Towards secure mobile cloud computing: A survey
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paper_title: Above the Clouds: A Berkeley View of Cloud Computing

paper_content:

Cloud Computing, the long-held dream of computing as a utility, has the potential to transform a large part of the IT industry, making software even more attractive as a service and shaping the way IT hardware is designed and purchased. Developers with innovative ideas for new Internet services no longer require the large capital outlays in hardware to deploy their service or the human expense to operate it. They need not be concerned about overprovisioning for a service whose popularity does not meet their predictions, thus wasting costly resources, or underprovisioning for one that becomes wildly popular, thus missing potential customers and revenue. Moreover, companies with large batch-oriented tasks can get results as quickly as their programs can scale, since using 1000 servers for one hour costs no more than using one server for 1000 hours. This elasticity of resources, without paying a premium for large scale, is unprecedented in the history of IT. Cloud Computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the datacenters that provide those services. The services themselves have long been referred to as Software as a Service (SaaS). The datacenter hardware and software is what we will call a Cloud. When a Cloud is made available in a pay-as-you-go manner to the general public, we call it a Public Cloud; the service being sold is Utility Computing. We use the term Private Cloud to refer to internal datacenters of a business or other organization, not made available to the general public. Thus, Cloud Computing is the sum of SaaS and Utility Computing, but does not include Private Clouds. People can be users or providers of SaaS, or users or providers of Utility Computing. We focus on SaaS Providers (Cloud Users) and Cloud Providers, which have received less attention than SaaS Users. From a hardware point of view, three aspects are new in Cloud Computing.
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paper_title: Scientific Cloud Computing: Early Definition and Experience

paper_content:

Cloud computing emerges as a new computing paradigm which aims to provide reliable, customized and QoS guaranteed computing dynamic environments for end-users. This paper reviews recent advances of Cloud computing, identifies the concepts and characters of scientific Clouds, and finally presents an example of scientific Cloud for data centers
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paper_title: A survey of mobile cloud computing: architecture, applications, and approaches

paper_content:

Together with an explosive growth of the mobile applications and emerging of cloud computing concept, mobile cloud computing (MCC) has been introduced to be a potential technology for mobile services. MCC integrates the cloud computing into the mobile environment and overcomes obstacles related to the performance (e.g., battery life, storage, and bandwidth), environment (e.g., heterogeneity, scalability, and availability), and security (e.g., reliability and privacy) discussed in mobile computing. This paper gives a survey of MCC, which helps general readers have an overview of the MCC including the definition, architecture, and applications. The issues, existing solutions, and approaches are presented. In addition, the future research directions of MCC are discussed. Copyright © 2011 John Wiley & Sons, Ltd.
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paper_title: T-Alloc: A practical energy efficient resource allocation algorithm for traditional data centers

paper_content:

Even if the cloud computing data centers are emerging as new candidates for replacement, traditional data centers are still growing rapidly in both number and capacity to meet the increasing demands for highly responsive computing and massive storage. Making the data center more energy efficient is therefore a necessary task. A traditional data center has many distinguished features with heterogeneous hardware, heterogeneous workload, average load rate focused, intensive time and personal effort for administrative tasks. This paper will propose a way of saving energy for traditional data centers considering all the above features. The basic idea is rearranging the allocation in such a way that energy is saved with suitable human effort. The simulation results show the efficiency of the method.
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paper_title: A Survey of Research on Mobile Cloud Computing

paper_content:

The rapid development of mobile computing and cloud computing trigger novel computing paradigm-----Mobile Cloud Computing. This paper review current research effort towards Mobile Computing. First, we present several challenges for the design of Mobile Cloud Computing service. Second, a concept model has been proposed to analyze related research work. Third, we survey recent Mobile Cloud Computing architecture, application partition & offloading, and context-aware service.
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paper_title: A survey on security issues in service delivery models of cloud computing

paper_content:

Cloud computing is a way to increase the capacity or add capabilities dynamically without investing in new infrastructure, training new personnel, or licensing new software. It extends Information Technology's (IT) existing capabilities. In the last few years, cloud computing has grown from being a promising business concept to one of the fast growing segments of the IT industry. But as more and more information on individuals and companies are placed in the cloud, concerns are beginning to grow about just how safe an environment it is. Despite of all the hype surrounding the cloud, enterprise customers are still reluctant to deploy their business in the cloud. Security is one of the major issues which reduces the growth of cloud computing and complications with data privacy and data protection continue to plague the market. The advent of an advanced model should not negotiate with the required functionalities and capabilities present in the current model. A new model targeting at improving features of an existing model must not risk or threaten other important features of the current model. The architecture of cloud poses such a threat to the security of the existing technologies when deployed in a cloud environment. Cloud service users need to be vigilant in understanding the risks of data breaches in this new environment. In this paper, a survey of the different security risks that pose a threat to the cloud is presented. This paper is a survey more specific to the different security issues that has emanated due to the nature of the service delivery models of a cloud computing system.
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paper_title: Energy-efficient and multifaceted resource management for profit-driven virtualized data centers

paper_content:

As long as virtualization has been introduced in data centers, it has been opening new chances for resource management. Nowadays, it is not just used as a tool for consolidating underused nodes and save power; it also allows new solutions to well-known challenges, such as heterogeneity management. Virtualization helps to encapsulate Web-based applications or HPC jobs in virtual machines (VMs) and see them as a single entity which can be managed in an easier and more efficient way. We propose a new scheduling policy that models and manages a virtualized data center. It focuses on the allocation of VMs in data center nodes according to multiple facets to optimize the provider's profit. In particular, it considers energy efficiency, virtualization overheads, and SLA violation penalties, and supports the outsourcing to external providers. The proposed approach is compared to other common scheduling policies, demonstrating that a provider can improve its benefit by 30% and save power while handling other challenges, such as resource outsourcing, in a better and more intuitive way than other typical approaches do.
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paper_title: Addressing cloud computing security issues

paper_content:

The recent emergence of cloud computing has drastically altered everyone's perception of infrastructure architectures, software delivery and development models. Projecting as an evolutionary step, following the transition from mainframe computers to client/server deployment models, cloud computing encompasses elements from grid computing, utility computing and autonomic computing, into an innovative deployment architecture. This rapid transition towards the clouds, has fuelled concerns on a critical issue for the success of information systems, communication and information security. From a security perspective, a number of unchartered risks and challenges have been introduced from this relocation to the clouds, deteriorating much of the effectiveness of traditional protection mechanisms. As a result the aim of this paper is twofold; firstly to evaluate cloud security by identifying unique security requirements and secondly to attempt to present a viable solution that eliminates these potential threats. This paper proposes introducing a Trusted Third Party, tasked with assuring specific security characteristics within a cloud environment. The proposed solution calls upon cryptography, specifically Public Key Infrastructure operating in concert with SSO and LDAP, to ensure the authentication, integrity and confidentiality of involved data and communications. The solution, presents a horizontal level of service, available to all implicated entities, that realizes a security mesh, within which essential trust is maintained.
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paper_title: DENS: Data Center Energy-Efficient Network-Aware Scheduling

paper_content:

In modern data centers, energy consumption accounts for a considerably large slice of operational expenses. The state of the art in data center energy optimization is focusing only on job distribution between computing servers based on workload or thermal profiles. This paper underlines the role of communication fabric in data center energy consumption and presents a scheduling approach that combines energy efficiency and network awareness, termed DENS. The DENS methodology balances the energy consumption of a data center, individual job performance, and traffic demands. The proposed approach optimizes the tradeoff between job consolidation (to minimize the amount of computing servers) and distribution of traffic patterns (to avoid hotspots in the data center network).
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paper_title: Energy-aware fast scheduling heuristics in heterogeneous computing systems

paper_content:

In heterogeneous computing systems it is crucial to schedule tasks in a manner that exploits the heterogeneity of the resources and applications to optimize systems performance. Moreover, the energy efficiency in these systems is of a great interest due to different concerns such as operational costs and environmental issues associated to carbon emissions. In this paper, we present a series of original low complexity energy efficient algorithms for scheduling. The main idea is to map a task to the machine that executes it fastest while the energy consumption is minimum. On the practical side, the set of experimental results showed that the proposed heuristics perform as efficiently as related approaches, demonstrating their applicability for the considered problem and its good scalability.
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paper_title: Lightweight and Compromise Resilient Storage Outsourcing with Distributed Secure Accessibility in Mobile Cloud Computing

paper_content:

Abstract Mobile Cloud Computing usually consists of front-end users who possess mobile devices and back-end cloud servers. This paradigm empowers users to pervasively access a large volume of storage resources with portable devices in a distributed and cooperative manner. During the period between uploading and downloading files (data), the privacy and integrity of files need to be guaranteed. To this end, a family of schemes are proposed for different situations. All schemes are lightweight in terms of computational overhead, resilient to storage compromise on mobile devices, and do not assume that trusted cloud servers are present. Corresponding algorithms are proposed in detail for guiding off-the-shelf implementation. The evaluation of security and performance is also extensively analyzed, justifying the applicability of the proposed schemes.
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paper_title: Comparison and analysis of eight scheduling heuristics for the optimization of energy consumption and makespan in large-scale distributed systems

paper_content:

In this paper, we study the problem of scheduling tasks on a distributed system, with the aim to simultaneously minimize energy consumption and makespan subject to the deadline constraints and the tasks’ memory requirements. A total of eight heuristics are introduced to solve the task scheduling problem. The set of heuristics include six greedy algorithms and two naturally inspired genetic algorithms. The heuristics are extensively simulated and compared using an simulation test-bed that utilizes a wide range of task heterogeneity and a variety of problem sizes. When evaluating the heuristics, we analyze the energy consumption, makespan, and execution time of each heuristic. The main benefit of this study is to allow readers to select an appropriate heuristic for a given scenario.
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paper_title: Energy-Aware High Performance Computing: A Taxonomy Study

paper_content:

To reduce the energy consumption and build a sustainable computer infrastructure now becomes a major goal of the high performance community. A number of research projects have been carried out in the field of energy-aware high performance computing. This paper is devoted to categorize energy-aware computing methods for the high-end computing infrastructures, such as servers, clusters, data centers, and Grids/Clouds. Based on a taxonomy of methods and system scales, this paper reviews the current status of energy-aware HPC research and summarizes open questions and research directions of software architecture for future energy-aware HPC studies.
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paper_title: Scalable and Energy-Efficient Scheduling Techniques for Large-Scale Systems

paper_content:

The scalability of a computing system can be identified by at least three components: (a) size, (b) geographical distribution, and (c) administrative constraints. Newer paradigms, such as clouds, grids, and clusters bring in more parameters to the aforementioned list, namely heterogeneity, energy consumption, and transparency. To optimize the performance of a computing system, it is manner that exploits heterogeneity and is scalable. Moreover, newer systems also demand energy efficiency as an integral part of schedulers. In this paper, we evaluate the behavior of low complexity energy-efficient algorithms for scheduling. The set of experimental results showed that the evaluated heuristics perform as efficiently as related approaches, demonstrating their applicability and scalability for the considered problem.
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paper_title: A self-adaptive weighted sum technique for the joint optimization of performance and power consumption in data centers

paper_content:

With data centers, end-users can realize the pervasive- ness of services that will be one day the cornerstone of our lives. However, data centers are often classified as computing systems that consume the most amounts of power. To circumvent such a problem, we propose a self-adaptive weighted sum methodology that jointly optimizes the performance and power consumption of any given data center. Compared to traditional methodologies for multi-objective optimization problems, the proposed self-adaptive weighted sum technique does not rely on a systematical change of weights during the optimization procedure. The proposed technique is compared with the greedy and LR heuristics for large-scale problems, and the optimal solution for small-scale problems implemented in LINDO. the experimental results revealed that the proposed self- adaptive weighted sum technique outperforms both of the heuristics and projects a competitive performance compared to the optimal solution.
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paper_title: Mobile Cloud Computing: A Comparison of Application Models

paper_content:

Cloud computing is an emerging concept combining many fields of computing. The foundation of cloud computing is the delivery of services, software and processing capacity over the Internet, reducing cost, increasing storage, automating systems, decoupling of service delivery from underlying technology, and providing flexibility and mobility of information. However, the actual realization of these benefits is far from being achieved for mobile applications and open many new research questions. In order to better understand how to facilitate the building of mobile cloud-based applications, we have surveyed existing work in mobile computing through the prism of cloud computing principles. We give a definition of mobile cloud coputing and provide an overview of the results from this review, in particular, models of mobile cloud applications. We also highlight research challenges in the area of mobile cloud computing. We conclude with recommendations for how this better understanding of mobile cloud computing can help building more powerful mobile applications.
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paper_title: Lightweight and Compromise Resilient Storage Outsourcing with Distributed Secure Accessibility in Mobile Cloud Computing

paper_content:

Abstract Mobile Cloud Computing usually consists of front-end users who possess mobile devices and back-end cloud servers. This paradigm empowers users to pervasively access a large volume of storage resources with portable devices in a distributed and cooperative manner. During the period between uploading and downloading files (data), the privacy and integrity of files need to be guaranteed. To this end, a family of schemes are proposed for different situations. All schemes are lightweight in terms of computational overhead, resilient to storage compromise on mobile devices, and do not assume that trusted cloud servers are present. Corresponding algorithms are proposed in detail for guiding off-the-shelf implementation. The evaluation of security and performance is also extensively analyzed, justifying the applicability of the proposed schemes.
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paper_title: Towards trusted cloud computing

paper_content:

Cloud computing infrastructures enable companies to cut costs by outsourcing computations on-demand. However, clients of cloud computing services currently have no means of verifying the confidentiality and integrity of their data and computation. ::: ::: To address this problem we propose the design of a trusted cloud computing platform (TCCP). TCCP enables Infrastructure as a Service (IaaS) providers such as Amazon EC2 to provide a closed box execution environment that guarantees confidential execution of guest virtual machines. Moreover, it allows users to attest to the IaaS provider and determine whether or not the service is secure before they launch their virtual machines.
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paper_title: Securing elastic applications on mobile devices for cloud computing

paper_content:

Cloud computing provides elastic computing infrastructure and resources which enable resource-on-demand and pay-as-you-go utility computing models. We believe that new applications can leverage these models to achieve new features that are not available for legacy applications. In our project we aim to build elastic applications which augment resource-constrained platforms, such as mobile phones, with elastic computing resources from clouds. An elastic application consists of one or more weblets, each of which can be launched on a device or cloud, and can be migrated between them according to dynamic changes of the computing environment or user preferences on the device. This paper overviews the general concept of this new application model, analyzes its unique security requirements, and presents our design considerations to build secure elastic applications. As first steps we propose a solution for authentication and secure session management between weblets running device side and those on the cloud. We then propose secure migration and how to authorize cloud weblets to access sensitive user data such as via external web services. We believe some principles in our solution can be applied in other cloud computing scenarios such as application integration between private and public clouds in an enterprise environment.
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paper_title: AlfredO: An Architecture for Flexible Interaction with Electronic Devices

paper_content:

Mobile phones are rapidly becoming the universal access point for computing, communication, and digital infrastructures. In this paper we explore the software architectures necessary to make the mobile phone a truly universal access point to any electronic infrastructure. We propose AlfredO, a lightweight middleware architecture that allows developers to construct applications in a modular way, organizing the applications into detachable tiers that can be distributed at will to dynamically configure multi-tier architectures between mobile phones and service providers. Through AlfredO, a phone can lease on-the-fly the client side of an application and immediately become a fully tailored client. Our experimental results indicate that AlfredO has very little overhead, it is scalable, and yields very low latency. To demonstrate the feasibility and potential of the platform, in the paper we also describe AlfredOShop, a prototype application for spontaneously controlling information screens from a mobile phone.
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paper_title: Augmented Smartphone Applications Through Clone Cloud Execution

paper_content:

Smartphones enable a new, rich user experience in pervasive computing, but their hardware is still very limited in terms of computation, memory, and energy reserves, thus limiting potential applications. In this paper, we propose a novel architecture that addresses these challenges via seamlessly--but partially--off-loading execution from the smartphone to a computational infrastructure hosting a cloud of smartphone clones. We outline new augmented execution opportunities for smartphones enabled by our CloneCloud architecture.
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paper_title: Calling the cloud: Enabling mobile phones as interfaces to cloud applications

paper_content:

Mobile phones are set to become the universal interface to online services and cloud computing applications. However, using them for this purpose today is limited to two configurations: applications either run on the phone or run on the server and are remotely accessed by the phone. These two options do not allow for a customized and flexible service interaction, limiting the possibilities for performance optimization as well. In this paper we present a middleware platform that can automatically distribute different layers of an application between the phone and the server, and optimize a variety of objective functions (latency, data transferred, cost, etc.). Our approach builds on existing technology for distributed module management and does not require new infrastructures. In the paper we discuss how to model applications as a consumption graph, and how to process it with a number of novel algorithms to find the optimal distribution of the application modules. The application is then dynamically deployed on the phone in an efficient and transparent manner. We have tested and validated our approach with extensive experiments and with two different applications. The results indicate that the techniques we propose can significantly optimize the performance of cloud applications when used from mobile phones.
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paper_title: Provable Data Possession of Resource-constrained Mobile Devices in Cloud Computing

paper_content:

Benefited from cloud storage services, users can save their cost of buying expensive storage and application servers, as well as deploying and maintaining applications. Meanwhile they lost the physical control of their data. So effective methods are needed to verify the correctness of the data stored at cloud servers, which are the research issues the Provable Data Possession (PDP) faced. The most important features in PDP are: 1) supporting for public, unlimited numbers of times of verification; 2) supporting for dynamic data update; 3) efficiency of storage space and computing. In mobile cloud computing, mobile end-users also need the PDP service. However, the computing workloads and storage burden of client in existing PDP schemes are too heavy to be directly used by the resource-constrained mobile devices. To solve this problem, with the integration of the trusted computing technology, this paper proposes a novel public PDP scheme, in which the trusted third-party agent (TPA) takes over most of the calculations from the mobile end-users. By using bilinear signature and Merkle hash tree (MHT), the scheme aggregates the verification tokens of the data file into one small signature to reduce communication and storage burden. MHT is also helpful to support dynamic data update. In our framework, the mobile terminal devices only need to generate some secret keys and random numbers with the help of trusted platform model (TPM) chips, and the needed computing workload and storage space is fit for mobile devices. Our scheme realizes provable secure storage service for resource-constrained mobile devices in mobile cloud computing.
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paper_title: A Ciphertext-Policy Attribute-Based Encryption Scheme with Constant Ciphertext Length

paper_content:

An Attribute-Based Encryption (ABE) is an encryption scheme, where users with some attributes can decrypt ciphertexts associated with these attributes. However, the length of the ciphertext depends on the number of attributes in previous ABE schemes. In this paper, we propose a new Ciphertext-Policy Attribute-Based Encryption (CP-ABE) with constant ciphertext length. Moreover, the number of pairing computations is also constant.
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paper_title: Efficient and secure data storage operations for mobile cloud computing

paper_content:

In a mobile cloud computing system, lightweight wireless communication devices extend cloud services into the sensing domain. A common mobile cloud secure data service is to inquiry the data from sensing devices. The data can be collected from multiple requesters, which may drain out the power of sensing devices quickly. Thus, an efficient data access control model is desired. To this end, we present a comprehensive security data inquiry framework for mobile cloud computing. Our solution focuses on the following two research directions: First, we present a novel Privacy Preserving Cipher Policy Attribute-Based Encryption (PP-CP-ABE) to protect sensing data. Using PP-CP-ABE, light-weight devices can securely outsource heavy encryption and decryption operations to cloud service providers, without revealing the data content. Second, we propose an Attribute Based Data Storage (ABDS) system as a cryptographic group-based access control mechanism. Our performance assessments demonstrate the security strength and efficiency of the presented solution in terms of computation, communication, and storage.
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paper_title: Lightweight and Compromise Resilient Storage Outsourcing with Distributed Secure Accessibility in Mobile Cloud Computing

paper_content:

Abstract Mobile Cloud Computing usually consists of front-end users who possess mobile devices and back-end cloud servers. This paradigm empowers users to pervasively access a large volume of storage resources with portable devices in a distributed and cooperative manner. During the period between uploading and downloading files (data), the privacy and integrity of files need to be guaranteed. To this end, a family of schemes are proposed for different situations. All schemes are lightweight in terms of computational overhead, resilient to storage compromise on mobile devices, and do not assume that trusted cloud servers are present. Corresponding algorithms are proposed in detail for guiding off-the-shelf implementation. The evaluation of security and performance is also extensively analyzed, justifying the applicability of the proposed schemes.
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paper_title: SDSM: A secure data service mechanism in mobile cloud computing

paper_content:

To enhance the security of mobile cloud users, a few proposals have been presented recently. However we argue that most of them are not suitable for mobile cloud where mobile users might join or leave the mobile networks arbitrarily. In this paper, we design a secure mobile user-based data service mechanism (SDSM) to provide confidentiality and fine-grained access control for data stored in the cloud. This mechanism enables the mobile users to enjoy a secure outsourced data services at a minimized security management overhead. The core idea of SDSM is that SDSM outsources not only the data but also the security management to the mobile cloud in a trust way. Our analysis shows that the proposed mechanism has many advantages over the existing traditional methods such as lower overhead and convenient update, which could better cater the requirements in mobile cloud computing scenarios.
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paper_title: Ciphertext-Policy Attribute-Based Encryption

paper_content:

In several distributed systems a user should only be able to access data if a user posses a certain set of credentials or attributes. Currently, the only method for enforcing such policies is to employ a trusted server to store the data and mediate access control. However, if any server storing the data is compromised, then the confidentiality of the data will be compromised. In this paper we present a system for realizing complex access control on encrypted data that we call ciphertext-policy attribute-based encryption. By using our techniques encrypted data can be kept confidential even if the storage server is untrusted; moreover, our methods are secure against collusion attacks. Previous attribute-based encryption systems used attributes to describe the encrypted data and built policies into user's keys; while in our system attributes are used to describe a user's credentials, and a party encrypting data determines a policy for who can decrypt. Thus, our methods are conceptually closer to traditional access control methods such as role-based access control (RBAC). In addition, we provide an implementation of our system and give performance measurements.
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paper_title: Energy-efficient incremental integrity for securing storage in mobile cloud computing

paper_content:

We present an energy-efficient protocol for ensuring the integrity of storage services in mobile cloud computing. The proposed protocol applies the concepts of incremental cryptography and trusted computing to design secure integrity data structures that protect the customer data while highly reducing the mobile client energy consumption and efficiently supporting dynamic data operations. The system design is analytically analyzed and experimentally implemented to demonstrate the energy savings it provides on mobile clients.
---
paper_title: Above the Clouds: A Berkeley View of Cloud Computing

paper_content:

Cloud Computing, the long-held dream of computing as a utility, has the potential to transform a large part of the IT industry, making software even more attractive as a service and shaping the way IT hardware is designed and purchased. Developers with innovative ideas for new Internet services no longer require the large capital outlays in hardware to deploy their service or the human expense to operate it. They need not be concerned about overprovisioning for a service whose popularity does not meet their predictions, thus wasting costly resources, or underprovisioning for one that becomes wildly popular, thus missing potential customers and revenue. Moreover, companies with large batch-oriented tasks can get results as quickly as their programs can scale, since using 1000 servers for one hour costs no more than using one server for 1000 hours. This elasticity of resources, without paying a premium for large scale, is unprecedented in the history of IT. Cloud Computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the datacenters that provide those services. The services themselves have long been referred to as Software as a Service (SaaS). The datacenter hardware and software is what we will call a Cloud. When a Cloud is made available in a pay-as-you-go manner to the general public, we call it a Public Cloud; the service being sold is Utility Computing. We use the term Private Cloud to refer to internal datacenters of a business or other organization, not made available to the general public. Thus, Cloud Computing is the sum of SaaS and Utility Computing, but does not include Private Clouds. People can be users or providers of SaaS, or users or providers of Utility Computing. We focus on SaaS Providers (Cloud Users) and Cloud Providers, which have received less attention than SaaS Users. From a hardware point of view, three aspects are new in Cloud Computing.
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paper_title: Incremental cryptography and application to virus protection

paper_content:

The goal ofincremental cryptography is to design cryptographic algorithms with the property that having applied the algorithm to a document, it is possible to quickly update the result of the algorithm for a modifled document, rather than having to re-compute it from scratch. In settings where cryptographic algorithms such as encryption or signatures are frequently applied to changing documents, dramatic e‐ciency improvements can be achieved. One such setting is the use of authentication tags for virus protection. We consider documents that can be modifled by powerful (and realistic) document modiflcation operations such as insertion and deletion of character-strings (or equivalently cut and paste of text). We provide e‐cient incremental signature and message authentication schemes supporting the above document modiflcation operations. They meet a strong notion of tamper-proof security which is appropriate for the virus protection setting. We initiate a study of incremental encryption, providing deflnitions as well as solutions. Finally, we raise the novel issue of \privacy" of incremental authentication schemes.
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paper_title: Incremental Cryptography: The Case of Hashing and Signing

paper_content:

We initiate the investigation of a new kind of efficiency for cryptographic transformations. The idea is that having once applied the transformation to some document M, the time to update the result upon modification of M should be "proportional" to the "amount of modification" done to M. Thereby one obtains much faster cryptographic primitives for environments where closely related documents are undergoing the same cryptographic transformations.We provide some basic definitions enabling treatment of the new notion. We then exemplify our approach by suggesting incremental schemes for hashing and signing which are efficient according to our new measure.
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paper_title: Energy-efficient incremental integrity for securing storage in mobile cloud computing

paper_content:

We present an energy-efficient protocol for ensuring the integrity of storage services in mobile cloud computing. The proposed protocol applies the concepts of incremental cryptography and trusted computing to design secure integrity data structures that protect the customer data while highly reducing the mobile client energy consumption and efficiently supporting dynamic data operations. The system design is analytically analyzed and experimentally implemented to demonstrate the energy savings it provides on mobile clients.
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paper_title: Achieving Secure, Scalable, and Fine-grained Data Access Control in Cloud Computing

paper_content:

Cloud computing is an emerging computing paradigm in which resources of the computing infrastructure are provided as services over the Internet. As promising as it is, this paradigm also brings forth many new challenges for data security and access control when users outsource sensitive data for sharing on cloud servers, which are not within the same trusted domain as data owners. To keep sensitive user data confidential against untrusted servers, existing solutions usually apply cryptographic methods by disclosing data decryption keys only to authorized users. However, in doing so, these solutions inevitably introduce a heavy computation overhead on the data owner for key distribution and data management when fine-grained data access control is desired, and thus do not scale well. The problem of simultaneously achieving fine-grainedness, scalability, and data confidentiality of access control actually still remains unresolved. This paper addresses this challenging open issue by, on one hand, defining and enforcing access policies based on data attributes, and, on the other hand, allowing the data owner to delegate most of the computation tasks involved in fine-grained data access control to untrusted cloud servers without disclosing the underlying data contents. We achieve this goal by exploiting and uniquely combining techniques of attribute-based encryption (ABE), proxy re-encryption, and lazy re-encryption. Our proposed scheme also has salient properties of user access privilege confidentiality and user secret key accountability. Extensive analysis shows that our proposed scheme is highly efficient and provably secure under existing security models.
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paper_title: SDSM: A secure data service mechanism in mobile cloud computing

paper_content:

To enhance the security of mobile cloud users, a few proposals have been presented recently. However we argue that most of them are not suitable for mobile cloud where mobile users might join or leave the mobile networks arbitrarily. In this paper, we design a secure mobile user-based data service mechanism (SDSM) to provide confidentiality and fine-grained access control for data stored in the cloud. This mechanism enables the mobile users to enjoy a secure outsourced data services at a minimized security management overhead. The core idea of SDSM is that SDSM outsources not only the data but also the security management to the mobile cloud in a trust way. Our analysis shows that the proposed mechanism has many advantages over the existing traditional methods such as lower overhead and convenient update, which could better cater the requirements in mobile cloud computing scenarios.
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paper_title: Identity-based proxy re-encryption

paper_content:

In a proxy re-encryption scheme a semi-trusted proxy converts a ciphertext for Alice into a ciphertext for Bob without seeing the underlying plaintext. A number of solutions have been proposed in the public-key setting. In this paper, we address the problem of Identity-Based proxy re-encryption, where ciphertexts are transformed from one identityto another. Our schemes are compatible with current IBE deployments and do not require any extra work from the IBE trusted-party key generator. In addition, they are non-interactive and one of them permits multiple re-encryptions. Their security is based on a standard assumption (DBDH) in the random oracle model.
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paper_title: Protocols for Public Key Cryptosystems

paper_content:

New Cryptographic protocols which take full advantage of the unique properties of public key cryptosystems are now evolving. Several protocols for public key distribution and for digital signatures are briefly compared with each other and with the conventional alternative.
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paper_title: Provable Data Possession of Resource-constrained Mobile Devices in Cloud Computing

paper_content:

Benefited from cloud storage services, users can save their cost of buying expensive storage and application servers, as well as deploying and maintaining applications. Meanwhile they lost the physical control of their data. So effective methods are needed to verify the correctness of the data stored at cloud servers, which are the research issues the Provable Data Possession (PDP) faced. The most important features in PDP are: 1) supporting for public, unlimited numbers of times of verification; 2) supporting for dynamic data update; 3) efficiency of storage space and computing. In mobile cloud computing, mobile end-users also need the PDP service. However, the computing workloads and storage burden of client in existing PDP schemes are too heavy to be directly used by the resource-constrained mobile devices. To solve this problem, with the integration of the trusted computing technology, this paper proposes a novel public PDP scheme, in which the trusted third-party agent (TPA) takes over most of the calculations from the mobile end-users. By using bilinear signature and Merkle hash tree (MHT), the scheme aggregates the verification tokens of the data file into one small signature to reduce communication and storage burden. MHT is also helpful to support dynamic data update. In our framework, the mobile terminal devices only need to generate some secret keys and random numbers with the help of trusted platform model (TPM) chips, and the needed computing workload and storage space is fit for mobile devices. Our scheme realizes provable secure storage service for resource-constrained mobile devices in mobile cloud computing.
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paper_title: A Review of the Diffie-Hellman Algorithm and its Use in Secure Internet Protocols

paper_content:

This paper will present an overview of the Diffie-Hellman Key Exchange algorithm and review several common cryptographic techniques in use on the Internet today that incorporate Diffie-Hellman.
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paper_title: Enabling public verifiability and data dynamics for storage security in cloud computing

paper_content:

Cloud Computing has been envisioned as the next-generation architecture of IT Enterprise. It moves the application software and databases to the centralized large data centers, where the management of the data and services may not be fully trustworthy. This unique paradigm brings about many new security challenges, which have not been well understood. This work studies the problem of ensuring the integrity of data storage in Cloud Computing. In particular, we consider the task of allowing a third party auditor (TPA), on behalf of the cloud client, to verify the integrity of the dynamic data stored in the cloud. The introduction of TPA eliminates the involvement of client through the auditing of whether his data stored in the cloud is indeed intact, which can be important in achieving economies of scale for Cloud Computing. The support for data dynamics via the most general forms of data operation, such as block modification, insertion and deletion, is also a significant step toward practicality, since services in Cloud Computing are not limited to archive or backup data only. While prior works on ensuring remote data integrity often lacks the support of either public verifiability or dynamic data operations, this paper achieves both. We first identify the difficulties and potential security problems of direct extensions with fully dynamic data updates from prior works and then show how to construct an elegant verification scheme for seamless integration of these two salient features in our protocol design. In particular, to achieve efficient data dynamics, we improve the Proof of Retrievability model [1] by manipulating the classic Merkle Hash Tree (MHT) construction for block tag authentication. Extensive security and performance analysis show that the proposed scheme is highly efficient and provably secure.
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paper_title: Lightweight and Compromise Resilient Storage Outsourcing with Distributed Secure Accessibility in Mobile Cloud Computing

paper_content:

Abstract Mobile Cloud Computing usually consists of front-end users who possess mobile devices and back-end cloud servers. This paradigm empowers users to pervasively access a large volume of storage resources with portable devices in a distributed and cooperative manner. During the period between uploading and downloading files (data), the privacy and integrity of files need to be guaranteed. To this end, a family of schemes are proposed for different situations. All schemes are lightweight in terms of computational overhead, resilient to storage compromise on mobile devices, and do not assume that trusted cloud servers are present. Corresponding algorithms are proposed in detail for guiding off-the-shelf implementation. The evaluation of security and performance is also extensively analyzed, justifying the applicability of the proposed schemes.
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paper_title: Efficient and secure data storage operations for mobile cloud computing

paper_content:

In a mobile cloud computing system, lightweight wireless communication devices extend cloud services into the sensing domain. A common mobile cloud secure data service is to inquiry the data from sensing devices. The data can be collected from multiple requesters, which may drain out the power of sensing devices quickly. Thus, an efficient data access control model is desired. To this end, we present a comprehensive security data inquiry framework for mobile cloud computing. Our solution focuses on the following two research directions: First, we present a novel Privacy Preserving Cipher Policy Attribute-Based Encryption (PP-CP-ABE) to protect sensing data. Using PP-CP-ABE, light-weight devices can securely outsource heavy encryption and decryption operations to cloud service providers, without revealing the data content. Second, we propose an Attribute Based Data Storage (ABDS) system as a cryptographic group-based access control mechanism. Our performance assessments demonstrate the security strength and efficiency of the presented solution in terms of computation, communication, and storage.
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paper_title: An Optimal Key Distribution Scheme for Secure Multicast Group Communication

paper_content:

Many IP multicast-based applications, such as multimedia conferencing, multiplayer games, require controlling the group memberships of senders and receivers. One common solution is to encrypt the data with a session key shared with all authorized senders/receivers. To efficiently update the session key in the event of member removal, many rooted-tree based group key distribution schemes have been proposed. However, most of the existing rooted-tree based schemes are not optimal. In other words, given the O(logN) storage overhead, the communication overhead is not minimized. On the other hand, although Flat Table scheme [1] achieves optimality [2], it is rather dismissed due to the vulnerability to collusion attacks. In this paper, we propose a key distribution scheme - EGK that attains the same optimality as Flat Table without collusion vulnerability. Additionally, EGK provides constant message size and requires O(logN) storage overhead at the group controller, which makes EGK suitable for applications containing a large number of multicasting group members. Moreover, adding members in EGK requires just one multicasting message. EGK is the first work with such features and out- performs all existing schemes.
---
paper_title: Ciphertext-Policy Attribute-Based Encryption

paper_content:

In several distributed systems a user should only be able to access data if a user posses a certain set of credentials or attributes. Currently, the only method for enforcing such policies is to employ a trusted server to store the data and mediate access control. However, if any server storing the data is compromised, then the confidentiality of the data will be compromised. In this paper we present a system for realizing complex access control on encrypted data that we call ciphertext-policy attribute-based encryption. By using our techniques encrypted data can be kept confidential even if the storage server is untrusted; moreover, our methods are secure against collusion attacks. Previous attribute-based encryption systems used attributes to describe the encrypted data and built policies into user's keys; while in our system attributes are used to describe a user's credentials, and a party encrypting data determines a policy for who can decrypt. Thus, our methods are conceptually closer to traditional access control methods such as role-based access control (RBAC). In addition, we provide an implementation of our system and give performance measurements.
---
paper_title: A Security Framework of Group Location-Based Mobile Applications in Cloud Computing

paper_content:

In this paper, we present a secure frame-work when the location information of mobile terminals is utilized in a cloud computing environment. Because cloud computing provides powerful storage capability and scalability, many application providers start migrating the data stored in their original databases to outsourced databases (ODB), such as AMAZONSIMPLEDB. However, because of the multiple tenants and multiple replicas of data in the cloud databases, the security issues of location-based services (LBS)become more serious in cloud computing. In this paper, we propose a security model for LBS using ODB and demonstrate how we can use distributed storage and international mobile subscriber identity (IMSI) as user identification to secure the location data. Enhanced privacy and authentication mechanisms on top of the suggested security framework are also proposed, which achieve significant improvements in privacy, authentication, and continuity when providing LBS in cloud computing. Simulation results show that network coding scheme has better performance than hash function scheme.
---
paper_title: Mobility Can Help: Protect User Identity with Dynamic Credential

paper_content:

Security becomes a prominent issue for mobile cloud computing since valuable information moves to the cloud. An important security problem is how the users identify themselves to the cloud. If an attacker is capable of faking or stealing user credentials, such as passwords and digital certificates, current security measures are not sufficient to safe-guard user’s valuable information in the cloud. This paper proposes a set of light weight algorithms to generate dynamic credential to defend against such powerful attackers. Many communication randomness, like the user mobility, were commonly believed harmful for security. In this paper, they are converted to helpful elements to generate dynamic credentials. Dynamic credential introduces interesting security properties.
---
paper_title: Securing elastic applications on mobile devices for cloud computing

paper_content:

Cloud computing provides elastic computing infrastructure and resources which enable resource-on-demand and pay-as-you-go utility computing models. We believe that new applications can leverage these models to achieve new features that are not available for legacy applications. In our project we aim to build elastic applications which augment resource-constrained platforms, such as mobile phones, with elastic computing resources from clouds. An elastic application consists of one or more weblets, each of which can be launched on a device or cloud, and can be migrated between them according to dynamic changes of the computing environment or user preferences on the device. This paper overviews the general concept of this new application model, analyzes its unique security requirements, and presents our design considerations to build secure elastic applications. As first steps we propose a solution for authentication and secure session management between weblets running device side and those on the cloud. We then propose secure migration and how to authorize cloud weblets to access sensitive user data such as via external web services. We believe some principles in our solution can be applied in other cloud computing scenarios such as application integration between private and public clouds in an enterprise environment.
---
paper_title: MobiCloud: Building Secure Cloud Framework for Mobile Computing and Communication

paper_content:

Cloud services can greatly enhance the computing capability of mobile devices. Mobile users can rely on the cloud to perform computationally intensive operations such as searching, data mining, and multimedia processing. In this paper, we propose a new mobile cloud framework called MobiCloud. In addition to providing traditional computation services, MobiCloud also enhances the operation of the ad hoc network itself by treating mobile devices as service nodes. The MobiCloud framework will enhance communication by addressing trust management, secure routing, and risk management issues in the network. A new class of applications can be developed using the enhanced processing power and connectivity provided by MobiCloud. Open research issues for MobiCloud are also discussed to outline future research directions.
---
paper_title: Towards a DL-based Additively Homomorphic Encryption Scheme

paper_content:

ElGamal scheme has been the first encryption scheme based on discrete logarithm. One of its main advantage is that it is simple, natural and efficient, but also that its security is clearly understood. However, one of its -- often forgotten -- disadvantages is that this scheme requires the encoding of messages into group elements, in order to be semantically secure. Unfortunately, this need prevents the scheme to be fully practical. ::: ::: In this paper, we propose a new way to deal with the problem of message encoding, which offers several advantages though some disadvantages. Our scheme is based on a quite simple combination of the standard ElGamal scheme with a message encoding inspired by the Naccache-Stern cryptosystem. We consider our solution as a new step towards the open problem of designing a discrete-logarithm based encryption scheme with the property of being additively homomorphic. Unfortunately, our construction is still not a complete solution. We hope however that it might give clues for a possible full solution.
---
paper_title: In-Device Spatial Cloaking for Mobile User Privacy Assisted by the Cloud

paper_content:

Spatial cloaking has been proposed and studied to protect mobile user privacy when using location based services (LBS). Traditional spatial cloaking methods are carried out by a trusted proxy known as location trusted server (LTS) to generate a region that contains at least k users for every request. The LTS is assumed to know the location of all users at all times, and perform the cloaking for all user requests. There are a number of disadvantages of relying on a single service for privacy preservation, including the scalability concern and the appropriate worry that this service “knows too much”. To ameliorate this single-service problem, in-device spatial cloaking may be more desirable. However, the sticky problem is that the device does not know, at the time of the request, the locations of all other users, which are necessary to obtain an appropriate cloaked region. With cloud services, it may be appropriate to assume that user-density information is available from cloud servers. These servers may collect user location information for different regions, or may use sophisticated method to estimate user densities for different places. When a request needs to be anonymized, the device goes to the cloud to acquire appropriate user density information to perform spatial cloaking. In this operating environment, traditional spatial cloaking methods such as Casper [9] need to be modified in order to guarantee safety. This paper proposes and studies a new algorithm and reports performance evaluation of the new algorithm and its optimized version, aiming at provably safe cloaking with minimized communication cost. Experimental results show that the new algorithms work well in the realistic evaluation environment.
---
paper_title: Meetings through the cloud: Privacy-preserving scheduling on mobile devices

paper_content:

Abstract: Mobile devices are increasingly being used to store and manage users' personal information, as well as to access popular third-party context-based services. Very often, these applications need to determine common availabilities among a set of user schedules, in order to allow colleagues, business partners and people to meet. The privacy of the scheduling operation is paramount to the success of such applications, as often users do not want to share their personal schedule details with other users or third-parties. In this paper, we propose practical and privacy-preserving solutions for mobile devices to the server-based scheduling problem. Our three novel algorithms take advantage of the homomorphic properties of well-known cryptosystems in order to privately and efficiently compute common user availabilities. We also formally outline the privacy requirements in such scheduling applications and we implement our solutions on real mobile devices. The experimental measurements and analytical results show that the proposed solutions not only satisfy the privacy properties but also fare better, in regard to computation and communication efficiency, compared to other well-known solutions. Finally, we assess the utility and expectations, in terms of privacy and usability, of the proposed solutions by means of a targeted survey and user-study of mobile-phone users.
---
paper_title: Authentication in the clouds: a framework and its application to mobile users

paper_content:

Cloud computing is a natural fit for mobile security. Typical handsets have input constraints and practical computational and power limitations, which must be respected by mobile security technologies in order to be effective. We describe how cloud computing can address these issues. Our approach is based on a flexible framework for supporting authentication decisions we call TrustCube (to manage the authentication infrastructure) and on a behavioral authentication approach referred to as implicit authentication (to translate user behavior into authentication scores). The combination results in a new authentication paradigm for users of mobile technologies, one where an appropriate balance between usability and trust can be managed through flexible policies and dynamic tuning.
---
paper_title: Securing elastic applications on mobile devices for cloud computing

paper_content:

Cloud computing provides elastic computing infrastructure and resources which enable resource-on-demand and pay-as-you-go utility computing models. We believe that new applications can leverage these models to achieve new features that are not available for legacy applications. In our project we aim to build elastic applications which augment resource-constrained platforms, such as mobile phones, with elastic computing resources from clouds. An elastic application consists of one or more weblets, each of which can be launched on a device or cloud, and can be migrated between them according to dynamic changes of the computing environment or user preferences on the device. This paper overviews the general concept of this new application model, analyzes its unique security requirements, and presents our design considerations to build secure elastic applications. As first steps we propose a solution for authentication and secure session management between weblets running device side and those on the cloud. We then propose secure migration and how to authorize cloud weblets to access sensitive user data such as via external web services. We believe some principles in our solution can be applied in other cloud computing scenarios such as application integration between private and public clouds in an enterprise environment.
---
paper_title: Towards an Elastic Application Model for Augmenting Computing Capabilities of Mobile Platforms

paper_content:

We propose a new elastic application model that enables the seamless and transparent use of cloud resources to augment the capability of resource-constrained mobile devices. The salient features of this model include the partition of a single application into multiple components called weblets, and a dynamic adaptation of weblet execution configuration. While a weblet can be platform independent (e.g., Java or .Net bytecode or Python script) or platform dependent (native code), its execution location is transparent – it can be run on a mobile device or migrated to the cloud, i.e., run on one or more nodes offered by an IaaS provider. Thus, an elastic application can augment the capabilities of a mobile device including computation power, storage, and network bandwidth, with the light of dynamic execution configuration according to device’s status including CPU load, memory, battery level, network connection quality, and user preferences. This paper presents the motivations, concepts, typical elasticity patterns, and cost consideration of elastic applications. We validate the augmentation capabilities with an implemented reference architecture and example applications.
---
paper_title: Mobility Can Help: Protect User Identity with Dynamic Credential

paper_content:

Security becomes a prominent issue for mobile cloud computing since valuable information moves to the cloud. An important security problem is how the users identify themselves to the cloud. If an attacker is capable of faking or stealing user credentials, such as passwords and digital certificates, current security measures are not sufficient to safe-guard user’s valuable information in the cloud. This paper proposes a set of light weight algorithms to generate dynamic credential to defend against such powerful attackers. Many communication randomness, like the user mobility, were commonly believed harmful for security. In this paper, they are converted to helpful elements to generate dynamic credentials. Dynamic credential introduces interesting security properties.
---
paper_title: Efficient processing of window queries in the pyramid data structure

paper_content:

Window operations serve as the basis of a number of queries that can be posed in a spatial database. Examples of these window-based queries include the exist query (i.e., determining whether or not a spatial feature exists inside a window) and the report query, (i.e., reporting the identity of all the features that exist inside a window). Algorithms are described for answering window queries in O ( n log log T ) time for a window of size n x n in a feature space (e.g., an image) of size T x T (e.g., pixel elements). The significance of this result is that even though the window contains n 2 pixel elements, the worst-case time complexity of the algorithms is almost linearly proportional (and not quadratic) to the window diameter, and does not depend on other factors. The above complexity bounds are achieved via the introduction of the incomplete pyramid data structure (a variant of the pyramid data structure) as the underlying representation to store spatial features and to answer queries on them.
---
paper_title: In-Device Spatial Cloaking for Mobile User Privacy Assisted by the Cloud

paper_content:

Spatial cloaking has been proposed and studied to protect mobile user privacy when using location based services (LBS). Traditional spatial cloaking methods are carried out by a trusted proxy known as location trusted server (LTS) to generate a region that contains at least k users for every request. The LTS is assumed to know the location of all users at all times, and perform the cloaking for all user requests. There are a number of disadvantages of relying on a single service for privacy preservation, including the scalability concern and the appropriate worry that this service “knows too much”. To ameliorate this single-service problem, in-device spatial cloaking may be more desirable. However, the sticky problem is that the device does not know, at the time of the request, the locations of all other users, which are necessary to obtain an appropriate cloaked region. With cloud services, it may be appropriate to assume that user-density information is available from cloud servers. These servers may collect user location information for different regions, or may use sophisticated method to estimate user densities for different places. When a request needs to be anonymized, the device goes to the cloud to acquire appropriate user density information to perform spatial cloaking. In this operating environment, traditional spatial cloaking methods such as Casper [9] need to be modified in order to guarantee safety. This paper proposes and studies a new algorithm and reports performance evaluation of the new algorithm and its optimized version, aiming at provably safe cloaking with minimized communication cost. Experimental results show that the new algorithms work well in the realistic evaluation environment.
---
paper_title: MobiCloud: Building Secure Cloud Framework for Mobile Computing and Communication

paper_content:

Cloud services can greatly enhance the computing capability of mobile devices. Mobile users can rely on the cloud to perform computationally intensive operations such as searching, data mining, and multimedia processing. In this paper, we propose a new mobile cloud framework called MobiCloud. In addition to providing traditional computation services, MobiCloud also enhances the operation of the ad hoc network itself by treating mobile devices as service nodes. The MobiCloud framework will enhance communication by addressing trust management, secure routing, and risk management issues in the network. A new class of applications can be developed using the enhanced processing power and connectivity provided by MobiCloud. Open research issues for MobiCloud are also discussed to outline future research directions.
---
paper_title: NetFPGA--An Open Platform for Gigabit-Rate Network Switching and Routing

paper_content:

The NetFPGA platform enables students and researchers to build high-performance networking systems in hardware. A new version of the NetFPGA platform has been developed and is available for use by the academic community. The NetFPGA 2.1 platform now has interfaces that can be parameterized, therefore enabling development of modular hardware designs with varied word sizes. It also includes more logic and faster memory than the previous platform. Field Programmable Gate Array (FPGA) logic is used to implement the core data processing functions while software running on embedded cores within the FPGA and/or programs running on an attached host computer implement only control functions. Reference designs and component libraries have been developed for the CS344 course at Stanford University. Open-source Verilog code is available for download from the project website.
---
paper_title: Identity-based proxy re-encryption

paper_content:

In a proxy re-encryption scheme a semi-trusted proxy converts a ciphertext for Alice into a ciphertext for Bob without seeing the underlying plaintext. A number of solutions have been proposed in the public-key setting. In this paper, we address the problem of Identity-Based proxy re-encryption, where ciphertexts are transformed from one identityto another. Our schemes are compatible with current IBE deployments and do not require any extra work from the IBE trusted-party key generator. In addition, they are non-interactive and one of them permits multiple re-encryptions. Their security is based on a standard assumption (DBDH) in the random oracle model.
---
paper_title: MobiCloud: Building Secure Cloud Framework for Mobile Computing and Communication

paper_content:

Cloud services can greatly enhance the computing capability of mobile devices. Mobile users can rely on the cloud to perform computationally intensive operations such as searching, data mining, and multimedia processing. In this paper, we propose a new mobile cloud framework called MobiCloud. In addition to providing traditional computation services, MobiCloud also enhances the operation of the ad hoc network itself by treating mobile devices as service nodes. The MobiCloud framework will enhance communication by addressing trust management, secure routing, and risk management issues in the network. A new class of applications can be developed using the enhanced processing power and connectivity provided by MobiCloud. Open research issues for MobiCloud are also discussed to outline future research directions.
---
paper_title: Authentication in the clouds: a framework and its application to mobile users

paper_content:

Cloud computing is a natural fit for mobile security. Typical handsets have input constraints and practical computational and power limitations, which must be respected by mobile security technologies in order to be effective. We describe how cloud computing can address these issues. Our approach is based on a flexible framework for supporting authentication decisions we call TrustCube (to manage the authentication infrastructure) and on a behavioral authentication approach referred to as implicit authentication (to translate user behavior into authentication scores). The combination results in a new authentication paradigm for users of mobile technologies, one where an appropriate balance between usability and trust can be managed through flexible policies and dynamic tuning.
---
paper_title: Provable Data Possession of Resource-constrained Mobile Devices in Cloud Computing

paper_content:

Benefited from cloud storage services, users can save their cost of buying expensive storage and application servers, as well as deploying and maintaining applications. Meanwhile they lost the physical control of their data. So effective methods are needed to verify the correctness of the data stored at cloud servers, which are the research issues the Provable Data Possession (PDP) faced. The most important features in PDP are: 1) supporting for public, unlimited numbers of times of verification; 2) supporting for dynamic data update; 3) efficiency of storage space and computing. In mobile cloud computing, mobile end-users also need the PDP service. However, the computing workloads and storage burden of client in existing PDP schemes are too heavy to be directly used by the resource-constrained mobile devices. To solve this problem, with the integration of the trusted computing technology, this paper proposes a novel public PDP scheme, in which the trusted third-party agent (TPA) takes over most of the calculations from the mobile end-users. By using bilinear signature and Merkle hash tree (MHT), the scheme aggregates the verification tokens of the data file into one small signature to reduce communication and storage burden. MHT is also helpful to support dynamic data update. In our framework, the mobile terminal devices only need to generate some secret keys and random numbers with the help of trusted platform model (TPM) chips, and the needed computing workload and storage space is fit for mobile devices. Our scheme realizes provable secure storage service for resource-constrained mobile devices in mobile cloud computing.
---
paper_title: Achieving Secure, Scalable, and Fine-grained Data Access Control in Cloud Computing

paper_content:

Cloud computing is an emerging computing paradigm in which resources of the computing infrastructure are provided as services over the Internet. As promising as it is, this paradigm also brings forth many new challenges for data security and access control when users outsource sensitive data for sharing on cloud servers, which are not within the same trusted domain as data owners. To keep sensitive user data confidential against untrusted servers, existing solutions usually apply cryptographic methods by disclosing data decryption keys only to authorized users. However, in doing so, these solutions inevitably introduce a heavy computation overhead on the data owner for key distribution and data management when fine-grained data access control is desired, and thus do not scale well. The problem of simultaneously achieving fine-grainedness, scalability, and data confidentiality of access control actually still remains unresolved. This paper addresses this challenging open issue by, on one hand, defining and enforcing access policies based on data attributes, and, on the other hand, allowing the data owner to delegate most of the computation tasks involved in fine-grained data access control to untrusted cloud servers without disclosing the underlying data contents. We achieve this goal by exploiting and uniquely combining techniques of attribute-based encryption (ABE), proxy re-encryption, and lazy re-encryption. Our proposed scheme also has salient properties of user access privilege confidentiality and user secret key accountability. Extensive analysis shows that our proposed scheme is highly efficient and provably secure under existing security models.
---
paper_title: MobiCloud: Building Secure Cloud Framework for Mobile Computing and Communication

paper_content:

Cloud services can greatly enhance the computing capability of mobile devices. Mobile users can rely on the cloud to perform computationally intensive operations such as searching, data mining, and multimedia processing. In this paper, we propose a new mobile cloud framework called MobiCloud. In addition to providing traditional computation services, MobiCloud also enhances the operation of the ad hoc network itself by treating mobile devices as service nodes. The MobiCloud framework will enhance communication by addressing trust management, secure routing, and risk management issues in the network. A new class of applications can be developed using the enhanced processing power and connectivity provided by MobiCloud. Open research issues for MobiCloud are also discussed to outline future research directions.
---
paper_title: A Review of the Diffie-Hellman Algorithm and its Use in Secure Internet Protocols

paper_content:

This paper will present an overview of the Diffie-Hellman Key Exchange algorithm and review several common cryptographic techniques in use on the Internet today that incorporate Diffie-Hellman.
---
paper_title: Identity-based proxy re-encryption

paper_content:

In a proxy re-encryption scheme a semi-trusted proxy converts a ciphertext for Alice into a ciphertext for Bob without seeing the underlying plaintext. A number of solutions have been proposed in the public-key setting. In this paper, we address the problem of Identity-Based proxy re-encryption, where ciphertexts are transformed from one identityto another. Our schemes are compatible with current IBE deployments and do not require any extra work from the IBE trusted-party key generator. In addition, they are non-interactive and one of them permits multiple re-encryptions. Their security is based on a standard assumption (DBDH) in the random oracle model.
---
paper_title: A Security Framework of Group Location-Based Mobile Applications in Cloud Computing

paper_content:

In this paper, we present a secure frame-work when the location information of mobile terminals is utilized in a cloud computing environment. Because cloud computing provides powerful storage capability and scalability, many application providers start migrating the data stored in their original databases to outsourced databases (ODB), such as AMAZONSIMPLEDB. However, because of the multiple tenants and multiple replicas of data in the cloud databases, the security issues of location-based services (LBS)become more serious in cloud computing. In this paper, we propose a security model for LBS using ODB and demonstrate how we can use distributed storage and international mobile subscriber identity (IMSI) as user identification to secure the location data. Enhanced privacy and authentication mechanisms on top of the suggested security framework are also proposed, which achieve significant improvements in privacy, authentication, and continuity when providing LBS in cloud computing. Simulation results show that network coding scheme has better performance than hash function scheme.
---
paper_title: MobiCloud: Building Secure Cloud Framework for Mobile Computing and Communication

paper_content:

Cloud services can greatly enhance the computing capability of mobile devices. Mobile users can rely on the cloud to perform computationally intensive operations such as searching, data mining, and multimedia processing. In this paper, we propose a new mobile cloud framework called MobiCloud. In addition to providing traditional computation services, MobiCloud also enhances the operation of the ad hoc network itself by treating mobile devices as service nodes. The MobiCloud framework will enhance communication by addressing trust management, secure routing, and risk management issues in the network. A new class of applications can be developed using the enhanced processing power and connectivity provided by MobiCloud. Open research issues for MobiCloud are also discussed to outline future research directions.
---
paper_title: Location-Based Services for Mobile Telephony: a Study of Users' Privacy Concerns

paper_content:

Context-aware computing often involves tracking peoples' location. Many studies and applications highlight the importance of keeping people's location information private. We discuss two types of location- based services; location-tracking services that are based on other parties tracking the user's location and position-aware services that rely on the device's knowledge of its own location. We present an experimental case study that examines people's concern for location privacy and compare this to the use of location-based services. We find that even though the perceived usefulness of the two different types of services is the same, location- tracking services generate more concern for privacy than position-aware services. We conclude that development emphasis should be given to position-aware services but that location-tracking services have a potential for success if users are given a simple option for turning the location-tracking off.
---
paper_title: Meetings through the cloud: Privacy-preserving scheduling on mobile devices

paper_content:

Abstract: Mobile devices are increasingly being used to store and manage users' personal information, as well as to access popular third-party context-based services. Very often, these applications need to determine common availabilities among a set of user schedules, in order to allow colleagues, business partners and people to meet. The privacy of the scheduling operation is paramount to the success of such applications, as often users do not want to share their personal schedule details with other users or third-parties. In this paper, we propose practical and privacy-preserving solutions for mobile devices to the server-based scheduling problem. Our three novel algorithms take advantage of the homomorphic properties of well-known cryptosystems in order to privately and efficiently compute common user availabilities. We also formally outline the privacy requirements in such scheduling applications and we implement our solutions on real mobile devices. The experimental measurements and analytical results show that the proposed solutions not only satisfy the privacy properties but also fare better, in regard to computation and communication efficiency, compared to other well-known solutions. Finally, we assess the utility and expectations, in terms of privacy and usability, of the proposed solutions by means of a targeted survey and user-study of mobile-phone users.
---
paper_title: Public-Key Cryptosystems Based on Composite Degree Residuosity Classes

paper_content:

This paper investigates a novel computational problem, namely the Composite Residuosity Class Problem, and its applications to public-key cryptography. We propose a new trapdoor mechanism and derive from this technique three encryption schemes : a trapdoor permutation and two homomorphic probabilistic encryption schemes computationally comparable to RSA. Our cryptosystems, based on usual modular arithmetics, are provably secure under appropriate assumptions in the standard model.
---
paper_title: Authentication in the clouds: a framework and its application to mobile users

paper_content:

Cloud computing is a natural fit for mobile security. Typical handsets have input constraints and practical computational and power limitations, which must be respected by mobile security technologies in order to be effective. We describe how cloud computing can address these issues. Our approach is based on a flexible framework for supporting authentication decisions we call TrustCube (to manage the authentication infrastructure) and on a behavioral authentication approach referred to as implicit authentication (to translate user behavior into authentication scores). The combination results in a new authentication paradigm for users of mobile technologies, one where an appropriate balance between usability and trust can be managed through flexible policies and dynamic tuning.
---

Title: Towards secure mobile cloud computing: A survey

Section 1: Introduction
Description 1: Provide an in-depth understanding of Mobile Cloud Computing (MCC) and its background in cloud computing.

Section 2: Security threats and counter measures
Description 2: Discuss the challenges and security issues in MCC along with potential counter measures and existing research.

Section 3: Evaluation criteria for security frameworks
Description 3: Introduce the parameters used for evaluating different security frameworks for MCC.

Section 4: Evaluation criteria for data security frameworks
Description 4: Detail the criteria such as basic theory, data protection, data integrity, scalability, and others, specific to data security frameworks.

Section 5: Evaluation criteria for application security frameworks
Description 5: Detail the criteria such as application type, security features, assumptions, etc., specific to application security frameworks.

Section 6: Survey of existing security frameworks for MCC
Description 6: Present and review various proposed security frameworks categorized into data security frameworks and application security frameworks.

Section 7: Data security frameworks
Description 7: Discuss various proposed data security frameworks in detail, providing countermeasure solutions and analysis.

Section 8: Application security frameworks
Description 8: Discuss various proposed application security frameworks in detail, addressing security for mobile applications or models in the MCC environment.

Section 9: Conclusion
Description 9: Summarize the findings, discuss the most critical security issues, and suggest future research directions.