Security in Qtopia Phones  Trolltech's Qtopia SXE takes a stab
at making open-source phones more secure.  No one wants an
insecure system, especially on a mobile or VoIP phone. Both
users and operators want to feel confident that their phones
won't be used secretly to send thousands of spam messages or
viruses or to transfer huge files. Linux in the mobile space
opens doors to everyone—including developers of malicious code.
A locked-down and secure system does not necessarily mean the
source code is closed.  Figure 1. Qtopia's Home Screen  The last
thing people want on their phones is a malware application that
secretly sends their details somewhere or launches a DOS attack
using their costly GPRS account. Together with the Linux
Intrusion Detection System (LIDS), Trolltech's Safe Execution
Environment (SXE) delivers a safe environment in which to allow
untrusted applications to be executed. Without SXE and LIDS, an
unsuspecting user could install an unknown package. This could
launch Qtopia's QCop, which ha