Cryptography — Open Access Journal

Wireless multimedia sensor networks will play a central role in the Internet of Things world, providing content-rich information for an uncountable number of monitoring and control scenarios. As more applications rely on multimedia data, security concerns gain attention, and new approaches arise to provide security for such networks. However, the usual resource constraints of processing, memory and the energy of multimedia-based sensors have brought different challenges for data encryption, which have driven the development of different security approaches. In this context, this article presents the state-of-the-art of cryptography in wireless multimedia sensor networks, surveying innovative works in this area and discussing promising research directions. Full article

This paper describes an authentication protocol using a Hardware-Embedded Delay PUF called HELP. HELP derives randomness from within-die path delay variations that occur along the paths within a hardware implementation of a cryptographic primitive, such as AES or SHA-3. The digitized timing values which represent the path delays are stored in a database on a secure server (verifier) as an alternative to storing PUF response bitstrings. This enables the development of an efficient authentication protocol that provides both privacy and mutual authentication. The security properties of the protocol are analyzed using data collected from a set of Xilinx Zynq FPGAs. Full article

The r-rounds Even–Mansour block cipher is a generalization of the well known Even–Mansour block cipher to r iterations. Attacks on this construction were described by Nikolić et al. and Dinur et al. for $r=2,3$. These attacks are only marginally better than brute force but are based on an interesting observation (due to Nikolić et al.): for a “typical” permutation P, the distribution of $P\left(x\right)\oplus x$ is not uniform. This naturally raises the following question. Let us call permutations for which the distribution of $P\left(x\right)\oplus x$ is uniformly “balanced” — is there a sufficiently large family of balanced permutations, and what is the security of the resulting Even–Mansour block cipher? We show how to generate families of balanced permutations from the Luby–Rackoff construction and use them to define a $2n$-bit block cipher from the 2-round Even–Mansour scheme. We prove that this cipher is indistinguishable from a random permutation of ${\{0,1\}}^{2n}$, for any adversary who has oracle access to the public permutations and to an encryption/decryption oracle, as long as the number of queries is $o(2^{n/2})$. As a practical example, we discuss the properties and the performance of a 256-bit block cipher that is based on our construction, and uses the Advanced Encryption Standard (AES), with a fixed key, as the public permutation. Full article

Cryptography has very long history, from ancient ciphers, such as Ceaser cipher, machine (or rotor) cipherx during WWI and WWII, and modern ciphers, which play a fundamental role in providing Confidentiality, Integrity, and Authentication services during transmission, processing, and storage of the sensitive data over the open or public networks. [...] Full article