Anonymous Authentication Protocols for Vehicular Ad Hoc Networks: An Overview
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paper_title: A multi-channel VANET providing concurrent safety and commercial services

paper_content:

In this paper, we propose a medium access control (MAC) protocol to support the multi-channel operation for dedicated short range communication (DSRC). In particular, we focus on the challenge of providing potentially high-bandwidth for non-safety applications provided by roadside infrastructure, without compromising safety communication occurring in a separate channel. In our architecture, when a vehicle approaches a DSRC service hot-spot, it switches from the ad-hoc mode to the coordinated mode (and switches back to ad-hoc as it leaves the hotspot's range). This coordinated mode is a variant of IEEE 802.11 PCF, modified for multi-channel operation. The coordinated mode maximizes utilization of the DSRC "service channels" in the DSRC hot-spots while allowing safety-message broadcasts to be received with high probability in a distinct "safety channel". When a vehicle is not within the range of a DSRC hot-spot, the vehicle can use any of the previously-proposed ad-hoc protocols. Our approach can use any of these ad-hoc protocols for its ad-hoc mode. The MAC protocol is simulated with realistic mobility trace, and verified that it meets our safety and service objectives.
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paper_title: A Privacy Aware and Efficient Security Infrastructure for Vehicular Ad Hoc Networks

paper_content:

VANETs have the potential to dramatically increase road safety by giving drivers more time to react adequately to dangerous situations. To prevent abuse of VANETs, a security infrastructure is needed that ensures security requirements like message integrity, confidentiality, and availability. After giving more details on the requirements we propose a security infrastructure that uses asymmetric as well as symmetric cryptography and tamper resistant hardware. While fulfilling the requirements, our proposal is especially designed to protect privacy of the VANET users and proves to be very efficient in terms of computational needs and bandwidth overhead.
---
paper_title: Trustworthy Privacy-Preserving Car-Generated Announcements in Vehicular Ad Hoc Networks

paper_content:

Vehicular ad hoc networks (VANETs) allow vehicle-to-vehicle communication and, in particular, vehicle-generated announcements. Provided that the trustworthiness of such announcements can be guaranteed, they can greatly increase the safety of driving. A new system for vehicle-generated announcements is presented that is secure against external and internal attackers attempting to send fake messages. Internal attacks are thwarted by using an endorsement mechanism based on threshold signatures. Our system outperforms previous proposals in message length and computational cost. Three different privacy-preserving variants of the system are also described to ensure that vehicles volunteering to generate and/or endorse trustworthy announcements do not have to sacrifice their privacy.
---
paper_title: Balanced Trustworthiness, Safety, and Privacy in Vehicle-to-Vehicle Communications

paper_content:

Vehicular ad hoc networks (VANETs) are being designed to improve traffic safety and efficiency. To meet this goal, the messages disseminated in VANETs must be trustworthy. We propose a privacy-preserving system that guarantees message trustworthiness in vehicle-to-vehicle (V2V) communications. Vehicle privacy is provided as long as a vehicle does not attempt to endorse the same message more than once. In spite of a message having been validly endorsed, if it is later found to be false, the system offers the possibility of a posteriori tracing the message generator and its endorsers. Our proposal demonstrates a number of distinctive features. The system is equipped with both a priori and a posteriori countermeasures. The threshold used for a priori endorsement can adaptively change according to the message urgency and traffic context, rather than being preset in the system design stage as in existing schemes. The verification of authenticated V2V messages is accelerated by batch message-processing techniques. Simulation results illustrate that the system maintains its performance under various traffic conditions.
---
paper_title: GSIS: A Secure and Privacy-Preserving Protocol for Vehicular Communications

paper_content:

In this paper, we first identify some unique design requirements in the aspects of security and privacy preservation for communications between different communication devices in vehicular ad hoc networks. We then propose a secure and privacy-preserving protocol based on group signature and identity (ID)-based signature techniques. We demonstrate that the proposed protocol cannot only guarantee the requirements of security and privacy but can also provide the desired traceability of each vehicle in the case where the ID of the message sender has to be revealed by the authority for any dispute event. Extensive simulation is conducted to verify the efficiency, effectiveness, and applicability of the proposed protocol in various application scenarios under different road systems.
---
paper_title: Medium Access Control Protocol Design for Vehicle–Vehicle Safety Messages

paper_content:

We propose a medium access control protocol design for a vehicle to send safety messages to other vehicles. We develop a Quality-of-Service (QoS) model for safety messages that are consistent with the active vehicle safety systems literature. Each message has a range and useful lifetime. The QoS target has each message received with high probability within its specified lifetime by each vehicle within its specified range. The protocol design is based on rapidly rebroadcasting each message multiple times within its lifetime in combination with the 802.11 Distributed Coordination Function. This makes the design compatible with emerging standards for Dedicated Short-Range Communication. Six different design variations are proposed. We derive equations and develop a simulation tool to assess the performance of the designs. Using these, we identify the best and most easily implemented designs. Design performance depends on the number of rebroadcasts, power, modulation, coding, and vehicular traffic volumes. We show that under certain assumptions on the loss probability tolerated by safety applications, the design is able to transport safety messages in vehicular ad hoc networks
---
paper_title: Proving Reliability of Anonymous Information in VANETs

paper_content:

Advances in wireless communications allow setting up communication links between vehicles for the exchange of information between them. Such vehicular ad hoc networks (VANETs) are important to enhance traffic safety since critical environmental conditions, such as road or traffic conditions, can be rapidly exchanged between vehicles in VANETs. However, to be useful for the driver, the information must be reliable, i.e., with great probability, the received information indeed reflects the actual situation. One approach to this is to regard information as reliable if it is confirmed by various sources. To achieve this, messages received must be distinguishable. This may become a threat against the privacy of drivers since by observing messages, vehicles may be traced. In this paper, we address the mentioned problems. We base the reliability of information on the number of different sources that confirmed specific information, and that number must be greater than a given threshold. We address the nontraceability by letting vehicles change their identity frequently. Our approach scales with respect to storage on the vehicle, as well as management of identities at a certification authority.
---
paper_title: The security of vehicular ad hoc networks

paper_content:

Vehicular networks are likely to become the most relevant form of mobile ad hoc networks. In this paper, we address the security of these networks. We provide a detailed threat analysis and devise an appropriate security architecture. We also describe some major design decisions still to be made, which in some cases have more than mere technical implications. We provide a set of security protocols, we show that they protect privacy and we analyze their robustness, and we carry out a quantitative assessment of the proposed solution.
---
paper_title: Threshold Anonymous Announcement in VANETs

paper_content:

Vehicular ad hoc networks (VANETs) allow wireless communications between vehicles without the aid of a central server. Reliable exchanges of information about road and traffic conditions allow a safer and more comfortable travelling environment. However, such profusion of information may allow unscrupulous parties to violate user privacy. On the other hand, a degree of auditability is desired for law enforcement and maintenance purposes. In this paper we propose a Threshold Anonymous Announcement service using direct anonymous attestation and one-time anonymous authentication to simultaneously achieve the seemingly contradictory goals of reliability, privacy and auditability.
---
paper_title: A novel secure communication scheme in vehicular ad hoc networks

paper_content:

Vehicular networks are very likely to become the most pervasive and applicable of mobile ad hoc networks in this decade. Vehicular Ad hoc NETwork (VANET) has become a hot emerging research subject, but few academic publications describing its security infrastructure. In this paper, we review the secure infrastructure of VANET, some potential applications and interesting security challenges. To cope with these security challenges, we propose a novel secure scheme for vehicular communication on VANETs. The proposed scheme not only protects the privacy but also maintains the liability in the secure communications by using session keys. We also analyze the robustness of the proposed scheme.
---
paper_title: Multi-use unidirectional proxy re-signatures

paper_content:

In 1998, Blaze, Bleumer, and Strauss suggested a cryptographic primitive named proxy re-signatures where a proxy turns a signature computed under Alice's secret key into one from Bob on the same message. The semi-trusted proxy does not learn either party's signing key and cannot sign arbitrary messages on behalf of Alice or Bob. At CCS 2005, Ateniese and Hohenberger revisited the primitive by providing appropriate security definitions and efficient constructions in the random oracle model. Nonetheless, they left open the problem of designing a multi-use unidirectional scheme where the proxy is able to translate in only one direction and signatures can be re-translated several times. ::: This paper solves this problem, suggested for the first time 10 years ago, and shows the first multi-hop unidirectional proxy re-signature schemes. We describe a random-oracle-using system that is secure in the Ateniese-Hohenberger model. The same technique also yields a similar construction in the standard model (i.e. without relying on random oracles). Both schemes are efficient and require newly defined -- but falsifiable -- Diffie-Hellman-like assumptions in bilinear groups.
---
paper_title: Enforcing Privacy Using Symmetric Random Key-Set in Vehicular Networks

paper_content:

Vehicular networks have attracted extensive attentions in recent years for their promises in improving safety and enabling other value-added services. Security and privacy are two integrated issues in the deployment of vehicular networks. Privacy-preserving authentication is a key technique in addressing these two issues. We propose a random keyset based authentication protocol that preserves user privacy under the zero-trust policy, in which no central authority is trusted with the user privacy. We show that the protocol can efficiently authenticate users without compromising their privacy with theoretical analysis. Malicious user identification and key revocation are also described
---
paper_title: DCS: An Efficient Distributed-Certificate-Service Scheme for Vehicular Networks

paper_content:

In this paper, we propose an efficient distributed-certificate-service (DCS) scheme for vehicular networks. The proposed scheme offers flexible interoperability for certificate service in heterogeneous administrative authorities and an efficient way for any onboard units (OBUs) to update its certificate from the available infrastructure roadside units (RSUs) in a timely manner. In addition, the DCS scheme introduces an aggregate batch-verification technique for authenticating certificate-based signatures, which significantly decreases the verification overhead. Security analysis and performance evaluation demonstrate that the DCS scheme can reduce the complexity of certificate management and achieve excellent security and efficiency for vehicular communications.
---
paper_title: Security in vehicular ad hoc networks

paper_content:

Vehicular communication networking is a promising approach to facilitating road safety, traffic management, and infotainment dissemination for drivers and passengers. One of the ultimate goals in the design of such networking is to resist various malicious abuses and security attacks. In this article we first review the current standardization process, which covers the methods of providing security services and preserving driver privacy for wireless access in vehicular environments (WAVE) applications. We then address two fundamental issues, certificate revocation and conditional privacy preservation, for making the standards practical. In addition, a suite of novel security mechanisms are introduced for achieving secure certificate revocation and conditional privacy preservation, which are considered among the most challenging design objectives in vehicular ad hoc networks.
---
paper_title: A secure and efficient communication scheme with authenticated key establishment and privacy preserving for vehicular ad hoc networks

paper_content:

Privacy and security should be paid much more attention in secure vehicular ad hoc networks (VANETs). However, as far as we know, few researches on secure VANET protocols have addressed both the privacy issues and authenticated key establishment. Therefore, in this work, a lightweight authenticated key establishment scheme with privacy preservation to secure the communications between mobile vehicles and roadside infrastructure in a VANET is proposed, which is called SECSPP. Our proposed scheme not only accomplishes vehicle-to-vehicle and vehicle-to-roadside infrastructure authentication and key establishment for communication between members, but also integrates blind signature techniques into the scheme in allowing mobile vehicles to anonymously interact with the services of roadside infrastructure. We also show that our scheme is efficient in its implementation on mobile vehicles in comparison with other related proposals.
---
paper_title: GSIS: A Secure and Privacy-Preserving Protocol for Vehicular Communications

paper_content:

In this paper, we first identify some unique design requirements in the aspects of security and privacy preservation for communications between different communication devices in vehicular ad hoc networks. We then propose a secure and privacy-preserving protocol based on group signature and identity (ID)-based signature techniques. We demonstrate that the proposed protocol cannot only guarantee the requirements of security and privacy but can also provide the desired traceability of each vehicle in the case where the ID of the message sender has to be revealed by the authority for any dispute event. Extensive simulation is conducted to verify the efficiency, effectiveness, and applicability of the proposed protocol in various application scenarios under different road systems.
---
paper_title: The security of vehicular ad hoc networks

paper_content:

Vehicular networks are likely to become the most relevant form of mobile ad hoc networks. In this paper, we address the security of these networks. We provide a detailed threat analysis and devise an appropriate security architecture. We also describe some major design decisions still to be made, which in some cases have more than mere technical implications. We provide a set of security protocols, we show that they protect privacy and we analyze their robustness, and we carry out a quantitative assessment of the proposed solution.
---
paper_title: A Privacy Aware and Efficient Security Infrastructure for Vehicular Ad Hoc Networks

paper_content:

VANETs have the potential to dramatically increase road safety by giving drivers more time to react adequately to dangerous situations. To prevent abuse of VANETs, a security infrastructure is needed that ensures security requirements like message integrity, confidentiality, and availability. After giving more details on the requirements we propose a security infrastructure that uses asymmetric as well as symmetric cryptography and tamper resistant hardware. While fulfilling the requirements, our proposal is especially designed to protect privacy of the VANET users and proves to be very efficient in terms of computational needs and bandwidth overhead.
---
paper_title: Trustworthy Privacy-Preserving Car-Generated Announcements in Vehicular Ad Hoc Networks

paper_content:

Vehicular ad hoc networks (VANETs) allow vehicle-to-vehicle communication and, in particular, vehicle-generated announcements. Provided that the trustworthiness of such announcements can be guaranteed, they can greatly increase the safety of driving. A new system for vehicle-generated announcements is presented that is secure against external and internal attackers attempting to send fake messages. Internal attacks are thwarted by using an endorsement mechanism based on threshold signatures. Our system outperforms previous proposals in message length and computational cost. Three different privacy-preserving variants of the system are also described to ensure that vehicles volunteering to generate and/or endorse trustworthy announcements do not have to sacrifice their privacy.
---
paper_title: Balanced Trustworthiness, Safety, and Privacy in Vehicle-to-Vehicle Communications

paper_content:

Vehicular ad hoc networks (VANETs) are being designed to improve traffic safety and efficiency. To meet this goal, the messages disseminated in VANETs must be trustworthy. We propose a privacy-preserving system that guarantees message trustworthiness in vehicle-to-vehicle (V2V) communications. Vehicle privacy is provided as long as a vehicle does not attempt to endorse the same message more than once. In spite of a message having been validly endorsed, if it is later found to be false, the system offers the possibility of a posteriori tracing the message generator and its endorsers. Our proposal demonstrates a number of distinctive features. The system is equipped with both a priori and a posteriori countermeasures. The threshold used for a priori endorsement can adaptively change according to the message urgency and traffic context, rather than being preset in the system design stage as in existing schemes. The verification of authenticated V2V messages is accelerated by batch message-processing techniques. Simulation results illustrate that the system maintains its performance under various traffic conditions.
---
paper_title: Proving Reliability of Anonymous Information in VANETs

paper_content:

Advances in wireless communications allow setting up communication links between vehicles for the exchange of information between them. Such vehicular ad hoc networks (VANETs) are important to enhance traffic safety since critical environmental conditions, such as road or traffic conditions, can be rapidly exchanged between vehicles in VANETs. However, to be useful for the driver, the information must be reliable, i.e., with great probability, the received information indeed reflects the actual situation. One approach to this is to regard information as reliable if it is confirmed by various sources. To achieve this, messages received must be distinguishable. This may become a threat against the privacy of drivers since by observing messages, vehicles may be traced. In this paper, we address the mentioned problems. We base the reliability of information on the number of different sources that confirmed specific information, and that number must be greater than a given threshold. We address the nontraceability by letting vehicles change their identity frequently. Our approach scales with respect to storage on the vehicle, as well as management of identities at a certification authority.
---
paper_title: Threshold Anonymous Announcement in VANETs

paper_content:

Vehicular ad hoc networks (VANETs) allow wireless communications between vehicles without the aid of a central server. Reliable exchanges of information about road and traffic conditions allow a safer and more comfortable travelling environment. However, such profusion of information may allow unscrupulous parties to violate user privacy. On the other hand, a degree of auditability is desired for law enforcement and maintenance purposes. In this paper we propose a Threshold Anonymous Announcement service using direct anonymous attestation and one-time anonymous authentication to simultaneously achieve the seemingly contradictory goals of reliability, privacy and auditability.
---
paper_title: A novel secure communication scheme in vehicular ad hoc networks

paper_content:

Vehicular networks are very likely to become the most pervasive and applicable of mobile ad hoc networks in this decade. Vehicular Ad hoc NETwork (VANET) has become a hot emerging research subject, but few academic publications describing its security infrastructure. In this paper, we review the secure infrastructure of VANET, some potential applications and interesting security challenges. To cope with these security challenges, we propose a novel secure scheme for vehicular communication on VANETs. The proposed scheme not only protects the privacy but also maintains the liability in the secure communications by using session keys. We also analyze the robustness of the proposed scheme.
---
paper_title: A secure and efficient communication scheme with authenticated key establishment and privacy preserving for vehicular ad hoc networks

paper_content:

Privacy and security should be paid much more attention in secure vehicular ad hoc networks (VANETs). However, as far as we know, few researches on secure VANET protocols have addressed both the privacy issues and authenticated key establishment. Therefore, in this work, a lightweight authenticated key establishment scheme with privacy preservation to secure the communications between mobile vehicles and roadside infrastructure in a VANET is proposed, which is called SECSPP. Our proposed scheme not only accomplishes vehicle-to-vehicle and vehicle-to-roadside infrastructure authentication and key establishment for communication between members, but also integrates blind signature techniques into the scheme in allowing mobile vehicles to anonymously interact with the services of roadside infrastructure. We also show that our scheme is efficient in its implementation on mobile vehicles in comparison with other related proposals.
---
paper_title: Balanced Trustworthiness, Safety, and Privacy in Vehicle-to-Vehicle Communications

paper_content:

Vehicular ad hoc networks (VANETs) are being designed to improve traffic safety and efficiency. To meet this goal, the messages disseminated in VANETs must be trustworthy. We propose a privacy-preserving system that guarantees message trustworthiness in vehicle-to-vehicle (V2V) communications. Vehicle privacy is provided as long as a vehicle does not attempt to endorse the same message more than once. In spite of a message having been validly endorsed, if it is later found to be false, the system offers the possibility of a posteriori tracing the message generator and its endorsers. Our proposal demonstrates a number of distinctive features. The system is equipped with both a priori and a posteriori countermeasures. The threshold used for a priori endorsement can adaptively change according to the message urgency and traffic context, rather than being preset in the system design stage as in existing schemes. The verification of authenticated V2V messages is accelerated by batch message-processing techniques. Simulation results illustrate that the system maintains its performance under various traffic conditions.
---
paper_title: Short Group Signatures

paper_content:

We construct a short group signature scheme. Signatures in our scheme are approximately the size of a standard RSA signature with the same security. Security of our group signature is based on the Strong Diffie-Hellman assumption and a new assumption in bilinear groups called the Decision Linear assumption. We prove security of our system, in the random oracle model, using a variant of the security definition for group signatures recently given by Bellare, Micciancio, and Warinschi.
---
paper_title: Verifier-Local revocation group signature schemes with backward unlinkability from bilinear maps

paper_content:

An approach of membership revocation in group signatures is verifier-local revocation (VLR for short). In this approach, only verifiers are involved in the revocation mechanism, while signers have no involvement. Thus, since signers have no load, this approach is suitable for mobile environments. Although Boneh and Shacham recently proposed a VLR group signature scheme from bilinear maps, this scheme does not satisfy the backward unlikability. The backward unlikability means that even after a member is revoked, signatures produced by the member before the revocation remain anonymous. In this paper, we propose VLR group signature schemes with the backward unlinkability from bilinear maps.
---
paper_title: Security in vehicular ad hoc networks

paper_content:

Vehicular communication networking is a promising approach to facilitating road safety, traffic management, and infotainment dissemination for drivers and passengers. One of the ultimate goals in the design of such networking is to resist various malicious abuses and security attacks. In this article we first review the current standardization process, which covers the methods of providing security services and preserving driver privacy for wireless access in vehicular environments (WAVE) applications. We then address two fundamental issues, certificate revocation and conditional privacy preservation, for making the standards practical. In addition, a suite of novel security mechanisms are introduced for achieving secure certificate revocation and conditional privacy preservation, which are considered among the most challenging design objectives in vehicular ad hoc networks.
---
paper_title: 1-out-of-n signatures from a variety of keys

paper_content:

This paper addresses how to use public-keys of several different signature schemes to generate 1-out-of-n signatures. Previously known constructions are for either RSA-keys only or DL-type keys only. We present a widely applicable method to construct a 1-out-of-n signature scheme that allows mixture use of different flavors of keys at the same time. The resulting scheme is more efficient than previous schemes even if it is used only with a single type of keys. With all DL-type keys, it yields shorter signatures than the ones of the previously known scheme based on the witness indistinguishable proofs by Cramer, et al. With all RSA-type keys, it reduces both computational and storage costs compared to that of the Ring signatures by Rivest, et al.
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paper_title: Threshold Ring Signatures and Applications to Ad-hoc Groups

paper_content:

In this paper, we investigate the recent paradigm for group signatures proposed by Rivest et al. at Asiacrypt '01. We first improve on their ring signature paradigm by showing that it holds under a strictly weaker assumption, namely the random oracle model rather than the ideal cipher. Then we provide extensions to make ring signatures suitable in practical situations, such as threshold schemes or ad-hoc groups. Finally we propose an efficient scheme for threshold scenarios based on a combinatorial method and provably secure in the random oracle model.
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paper_title: On the RS-Code Construction of Ring Signature Schemes and a Threshold Setting of RST

paper_content:

We propose a Reed-Solomon (RS) code construction of the 1-out-n (ring) signature scheme. It is obtained from the observation of the equivalency between the erasure correction technique of the RS code and the polynomial interpolation. The structure is very simple and yields a ring equation that can appropriately denoted by Z 1 + ... + Z n =v, which represents the summation of n evaluations of a polynomial. We also show how to extend the generic RST scheme [6] to a t-out-n threshold ring signature scheme.
---
paper_title: Short Group Signatures

paper_content:

We construct a short group signature scheme. Signatures in our scheme are approximately the size of a standard RSA signature with the same security. Security of our group signature is based on the Strong Diffie-Hellman assumption and a new assumption in bilinear groups called the Decision Linear assumption. We prove security of our system, in the random oracle model, using a variant of the security definition for group signatures recently given by Bellare, Micciancio, and Warinschi.
---
paper_title: How to leak a secret

paper_content:

In this paper we formalize the notion of a ring signature, which makes it possible to specify a set of possible signers without revealing which member actually produced the signature. Unlike group signatures, ring signatures have no group managers, no setup procedures, no revocation procedures, and no coordination: any user can choose any set of possible signers that includes himself, and sign any message by using his secret key and the others' public keys, without getting their approval or assistance. Ring signatures provide an elegant way to leak authoritative secrets in an anonymous way, to sign casual email in a way which can only be verified by its intended recipient, and to solve other problems in multiparty computations. The main contribution of this paper is a new construction of such signatures which is unconditionally signer-ambiguous, provably secure in the random oracle model, and exceptionally efficient: adding each ring member increases the cost of signing or verifying by a single modular multiplication and a single symmetric encryption.
---
paper_title: Enforcing Privacy Using Symmetric Random Key-Set in Vehicular Networks

paper_content:

Vehicular networks have attracted extensive attentions in recent years for their promises in improving safety and enabling other value-added services. Security and privacy are two integrated issues in the deployment of vehicular networks. Privacy-preserving authentication is a key technique in addressing these two issues. We propose a random keyset based authentication protocol that preserves user privacy under the zero-trust policy, in which no central authority is trusted with the user privacy. We show that the protocol can efficiently authenticate users without compromising their privacy with theoretical analysis. Malicious user identification and key revocation are also described
---
paper_title: k-Times anonymous authentication

paper_content:

We propose an authentication scheme in which users can be authenticated anonymously so long as times that they are authenticated is within an allowable number. The proposed scheme has two features that allow 1) no one, not even an authority, identify users who have been authenticated within the allowable number, and that allow 2) anyone to trace, without help from the authority, dishonest users who have been authenticated beyond the allowable number by using the records of these authentications. Although identity escrow/group signature schemes allow users to be anonymously authenticated, the authorities in these schemes have the unnecessary ability to trace any user. Moreover, since it is only the authority who is able to trace users, one needs to make cumbersome inquiries to the authority to see how many times a user has been authenticated. Our scheme can be applied to e-voting, e-cash, electronic coupons, and trial browsing of content. In these applications, our scheme, unlike the previous one, conceals users' participation from protocols and guarantees that they will remain anonymous to everyone.
---
paper_title: Defense against misbehavior in anonymous vehicular ad hoc networks

paper_content:

Vehicular ad hoc network (VANET) can offer various services and benefits to VANET users and thus deserves deployment effort. Misusing such network could cause destructive consequences. It is therefore necessary to discourage misbehavior and defend VANET systems against it, in order to ensure correct and smooth operations of the network. In this paper, we review the techniques for handling misbehavior in VANETs, particularly where anonymous communications are desired to conserve user privacy since it adds more complexity to the defense against misbehavior. A new scheme is proposed to punish misbehaving users and can be employed in both inter-vehicle and vehicle-to-infrastructure anonymous communications. Our scheme leverages some threshold authentication technique that dynamically revokes a user's credential, while providing the flexibility of whether to reveal the user's identity and tolerating unintentional misbehavior such as hardware malfunctioning.
---
paper_title: Trustworthy Privacy-Preserving Car-Generated Announcements in Vehicular Ad Hoc Networks

paper_content:

Vehicular ad hoc networks (VANETs) allow vehicle-to-vehicle communication and, in particular, vehicle-generated announcements. Provided that the trustworthiness of such announcements can be guaranteed, they can greatly increase the safety of driving. A new system for vehicle-generated announcements is presented that is secure against external and internal attackers attempting to send fake messages. Internal attacks are thwarted by using an endorsement mechanism based on threshold signatures. Our system outperforms previous proposals in message length and computational cost. Three different privacy-preserving variants of the system are also described to ensure that vehicles volunteering to generate and/or endorse trustworthy announcements do not have to sacrifice their privacy.
---
paper_title: Proving Reliability of Anonymous Information in VANETs

paper_content:

Advances in wireless communications allow setting up communication links between vehicles for the exchange of information between them. Such vehicular ad hoc networks (VANETs) are important to enhance traffic safety since critical environmental conditions, such as road or traffic conditions, can be rapidly exchanged between vehicles in VANETs. However, to be useful for the driver, the information must be reliable, i.e., with great probability, the received information indeed reflects the actual situation. One approach to this is to regard information as reliable if it is confirmed by various sources. To achieve this, messages received must be distinguishable. This may become a threat against the privacy of drivers since by observing messages, vehicles may be traced. In this paper, we address the mentioned problems. We base the reliability of information on the number of different sources that confirmed specific information, and that number must be greater than a given threshold. We address the nontraceability by letting vehicles change their identity frequently. Our approach scales with respect to storage on the vehicle, as well as management of identities at a certification authority.
---
paper_title: The security of vehicular ad hoc networks

paper_content:

Vehicular networks are likely to become the most relevant form of mobile ad hoc networks. In this paper, we address the security of these networks. We provide a detailed threat analysis and devise an appropriate security architecture. We also describe some major design decisions still to be made, which in some cases have more than mere technical implications. We provide a set of security protocols, we show that they protect privacy and we analyze their robustness, and we carry out a quantitative assessment of the proposed solution.
---
paper_title: A novel secure communication scheme in vehicular ad hoc networks

paper_content:

Vehicular networks are very likely to become the most pervasive and applicable of mobile ad hoc networks in this decade. Vehicular Ad hoc NETwork (VANET) has become a hot emerging research subject, but few academic publications describing its security infrastructure. In this paper, we review the secure infrastructure of VANET, some potential applications and interesting security challenges. To cope with these security challenges, we propose a novel secure scheme for vehicular communication on VANETs. The proposed scheme not only protects the privacy but also maintains the liability in the secure communications by using session keys. We also analyze the robustness of the proposed scheme.
---
paper_title: Divertible protocols and atomic proxy cryptography

paper_content:

First, we introduce the notion of divertibility as a protocol property as opposed to the existing notion as a language property (see Okamoto, Ohta [OO90]). We give a definition of protocol divertibility that applies to arbitrary 2-party protocols and is compatible with Okamoto and Ohta's definition in the case of interactive zero-knowledge proofs. Other important examples falling under the new definition are blind signature protocols. We propose a sufficiency criterion for divertibility that is satisfied by many existing protocols and which, surprisingly, generalizes to cover several protocols not normally associated with divertibility (e.g., Diffie-Hellman key exchange). Next, we introduce atomic proxy cryptography, in which an atomic proxy function, in conjunction with a public proxy key, converts ciphertexts (messages or signatures) for one key into ciphertexts for another. Proxy keys, once generated, may be made public and proxy functions applied in untrusted environments. We present atomic proxy functions for discrete-log-based encryption, identification, and signature schemes. It is not clear whether atomic proxy functions exist in general for all public-key cryptosystems. Finally, we discuss the relationship between divertibility and proxy cryptography.
---
paper_title: Multi-use unidirectional proxy re-signatures

paper_content:

In 1998, Blaze, Bleumer, and Strauss suggested a cryptographic primitive named proxy re-signatures where a proxy turns a signature computed under Alice's secret key into one from Bob on the same message. The semi-trusted proxy does not learn either party's signing key and cannot sign arbitrary messages on behalf of Alice or Bob. At CCS 2005, Ateniese and Hohenberger revisited the primitive by providing appropriate security definitions and efficient constructions in the random oracle model. Nonetheless, they left open the problem of designing a multi-use unidirectional scheme where the proxy is able to translate in only one direction and signatures can be re-translated several times. ::: This paper solves this problem, suggested for the first time 10 years ago, and shows the first multi-hop unidirectional proxy re-signature schemes. We describe a random-oracle-using system that is secure in the Ateniese-Hohenberger model. The same technique also yields a similar construction in the standard model (i.e. without relying on random oracles). Both schemes are efficient and require newly defined -- but falsifiable -- Diffie-Hellman-like assumptions in bilinear groups.
---
paper_title: A Privacy Aware and Efficient Security Infrastructure for Vehicular Ad Hoc Networks

paper_content:

VANETs have the potential to dramatically increase road safety by giving drivers more time to react adequately to dangerous situations. To prevent abuse of VANETs, a security infrastructure is needed that ensures security requirements like message integrity, confidentiality, and availability. After giving more details on the requirements we propose a security infrastructure that uses asymmetric as well as symmetric cryptography and tamper resistant hardware. While fulfilling the requirements, our proposal is especially designed to protect privacy of the VANET users and proves to be very efficient in terms of computational needs and bandwidth overhead.
---
paper_title: A novel secure communication scheme in vehicular ad hoc networks

paper_content:

Vehicular networks are very likely to become the most pervasive and applicable of mobile ad hoc networks in this decade. Vehicular Ad hoc NETwork (VANET) has become a hot emerging research subject, but few academic publications describing its security infrastructure. In this paper, we review the secure infrastructure of VANET, some potential applications and interesting security challenges. To cope with these security challenges, we propose a novel secure scheme for vehicular communication on VANETs. The proposed scheme not only protects the privacy but also maintains the liability in the secure communications by using session keys. We also analyze the robustness of the proposed scheme.
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paper_title: A secure and efficient communication scheme with authenticated key establishment and privacy preserving for vehicular ad hoc networks

paper_content:

Privacy and security should be paid much more attention in secure vehicular ad hoc networks (VANETs). However, as far as we know, few researches on secure VANET protocols have addressed both the privacy issues and authenticated key establishment. Therefore, in this work, a lightweight authenticated key establishment scheme with privacy preservation to secure the communications between mobile vehicles and roadside infrastructure in a VANET is proposed, which is called SECSPP. Our proposed scheme not only accomplishes vehicle-to-vehicle and vehicle-to-roadside infrastructure authentication and key establishment for communication between members, but also integrates blind signature techniques into the scheme in allowing mobile vehicles to anonymously interact with the services of roadside infrastructure. We also show that our scheme is efficient in its implementation on mobile vehicles in comparison with other related proposals.
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paper_title: Identity-based encryption from the Weil pairing

paper_content:

We propose a fully functional identity-based encryption (IBE) scheme. The scheme has chosen ciphertext security in the random oracle model assuming a variant of the computational Diffie--Hellman problem. Our system is based on bilinear maps between groups. The Weil pairing on elliptic curves is an example of such a map. We give precise definitions for secure IBE schemes and give several applications for such systems.
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Title: Anonymous Authentication Protocols for Vehicular Ad Hoc Networks: An Overview

Section 1: Attack Model
Description 1: Describe the various potential security attacks in VANETs, such as fake information attacks, message replay attacks, and impersonation attacks.

Section 2: Security Requirements
Description 2: Outline the necessary security requirements to counteract the potential threats in the aforementioned attack models for VANETs.

Section 3: Network Model
Description 3: Explain the architecture of VANETs, detailing the roles and interactions between OBUs, RSUs, and the TA.

Section 4: Group Signature-Based Scheme
Description 4: Introduce group signature-based protocols, their features, and how they ensure privacy while allowing a trusted authority to reveal the identity if needed.

Section 5: Ring Signature-Based Scheme
Description 5: Explain ring signature-based schemes, their properties of anonymity and spontaneity, and how they function in the context of VANETs.

Section 6: k-TAA-Based Scheme
Description 6: Describe k-times anonymous authentication (k-TAA) mechanisms, their components, and how they allow for limited anonymous access while preventing dishonest behaviors.

Section 7: Basic Scheme
Description 7: Discuss the large number of anonymous key based (LAB) protocols and the pros and cons of using such methods for anonymous authentication in VANETs.

Section 8: TESLA-Based Scheme
Description 8: Explain the TESLA protocol and its application in VANETs for providing efficient broadcast authentication with low communication and computation overhead.

Section 9: Proxy Re-Signature-Based Scheme
Description 9: Introduce proxy re-signature schemes and how they can be utilized to implement anonymizable signatures in VANETs.

Section 10: Confidentiality-Oriented Scheme
Description 10: Highlight the importance of confidentiality in VANETs and describe different protocols designed to ensure secure and private communications.

Section 11: Priori-Based Approach
Description 11: Examine priori countermeasures designed to prevent fake message generation by requiring message endorsement by several vehicles.

Section 12: An Example of Ring-Signature Based Anonymous Authentication Protocols
Description 12: Provide an example of a ring-signature based authentication protocol, including system initialization, message generation, verification, and fast tracing processes.

Section 13: Using the Taxonomies
Description 13: Discuss how the taxonomies of anonymous authentication protocols can be used to map, explore, and understand various strategies and their constraints in the field.

Section 14: Conclusion
Description 14: Summarize the key points of the survey and the proposed taxonomies, and provide directions for future research in the field of anonymous authentication protocols for VANETs.