Biblio

In this article, we introduce the MACH-2K trust overlay network and its architecture. MACH-2K's objectives are to (a) enhance the resiliency of emergency response and public service networks and (b) help build such networks in places, or at times, where network infrastructure is limited. Resiliency may be enhanced in an economic manner by building new ad hoc networks of private mobile devices and joining these to public service networks at specific trusted points. The major barrier to building resiliency by using private devices is ensuring security. MACH-2K uses device location and communication utility patterns to assign trust to devices, after owner approval. After trust is established, message confidentiality, privacy, and integrity may be implemented by well-known cryptographic means. MACH-2K devices may be then requested to forward or consume different types of messages depending on their current level of trust and utility.

The symmetric block ciphers, which represent a core element for building cryptographic communications systems and protocols, are used in providing message confidentiality, authentication and integrity. Various limitations in hardware and software resources, especially in terminal devices used in mobile communications, affect the selection of appropriate cryptosystem and its parameters. In this paper, an implementation of three symmetric ciphers (DES, 3DES, AES) used in different operating modes are analyzed on Android platform. The cryptosystems' performance is analyzed in different scenarios using several variable parameters: cipher, key size, plaintext size and number of threads. Also, the influence of parallelization supported by multi-core CPUs on cryptosystem performance is analyzed. Finally, some conclusions about the parameter selection for optimal efficiency are given.