Cipher

About: Cipher is a research topic. Over the lifetime, 9409 publications have been published within this topic receiving 110309 citations. The topic is also known as: cypher & cryptographic algorithm.

FIDES: lightweight authenticated cipher with side-channel resistance for constrained hardware

Abstract: In this paper, we present a novel lightweight authenticated cipher optimized for hardware implementations called Fides. It is an online nonce-based authenticated encryption scheme with authenticated data whose area requirements are as low as 793 GE and 1001 GE for 80-bit and 96-bit security, respectively. This is at least two times smaller than its closest competitors Hummingbird-2 and Grain-128a. While being extremely compact, Fides is both throughput and latency efficient, even in its most serial implementations. This is attained by our novel sponge-like design approach. Moreover, cryptographically optimal 5-bit and 6-bit S-boxes are used as basic nonlinear components while paying a special attention on the simplicity of providing first order side-channel resistance with threshold implementation.

Linear (Hull) and Algebraic Cryptanalysis of the Block Cipher PRESENT

Abstract: The contributions of this paper include the first linear hull and a revisit of the algebraic cryptanalysis of reduced-round variants of the block cipher PRESENT, under known-plaintext and ciphertext-only settings. We introduce a pure algebraic cryptanalysis of 5-round PRESENT and in one of our attacks we recover half of the bits of the key in less than three minutes using an ordinary desktop PC. The PRESENT block cipher is a design by Bogdanov et al. , announced in CHES 2007 and aimed at RFID tags and sensor networks. For our linear attacks, we can attack 25-round PRESENT with the whole code book, 296.68 25-round PRESENT encryptions, 240 blocks of memory and 0.61 success rate. Further we can extend the linear attack to 26-round with small success rate. As a further contribution of this paper we computed linear hulls in practice for the original PRESENT cipher, which corroborated and even improved on the predicted bias (and the corresponding attack complexities) of conventional linear relations based on a single linear trail.

Objects to be checked for authenticity, and method and apparatus for checking whether or not objects are authentic

Abstract: An object to be checked contains a large number of magnetic polymer elements scattered at random. Each of magnetic polymer elements is made up of an element main body formed of a high molecular material, and magnetic metal powder contained in the element main body. The magnetic polymer elements are integrally incorporated in paper and tangled with the wood pulp fibers of the paper three-dimensionally. In the manufacturing process of the object, a processing apparatus magnetically scans the magnetic polymer elements incorporated in the scanning region of the object while moving the scanning region at a predetermined speed, converts a detection signal obtained by the magnetic scan into a cipher code, and records the cipher code in a code indicator section. In the authenticity checking process, the processing apparatus magnetically scans the magnetic polymer elements once again, and a detection signal obtained thereby is collated with the cipher code recorded in the code indicator section. When the detection signal and the cipher code agree with each other, the object is determined as being authentic.

White Box Cryptography: Another Attempt ?

Abstract: At CMS 2006 Bringer et al. show how to conceal the alge- braic structure of a \traceable block cipher" by adding perturbations to its description. We here exploit and strengthen their ideas by further perturbing the representation of a cipher towards a white box implemen- tation. Our technique is quite general, and we apply it { as a challenging example in the domain of white box cryptography { to a variant of the block cipher AES.