Підвищення стійкості функцій хешування в схемах автентифікації

Розглянуто проблеми, пов’язані з використанням функцій хешування в схемах автентифікації. Запропоновано метод усунення атаки на подовження/скорочення повідомлення.Problems of using hash-function at authentification were considered. Elimination method of message lengthening/abridge attack was offered

Высокоскоростной UMAC алгоритм

Розглядається високошвидкістний UMAC алгоритм, характеристики, параметри та оцінка таємності.The high-speed UMAC algorithm, characteristics, parameters and an estimation of privacy are considered

Regular and almost universal hashing: an efficient implementation

Random hashing can provide guarantees regarding the performance of data structures such as hash tables---even in an adversarial setting. Many existing families of hash functions are universal: given two data objects, the probability that they have the same hash value is low given that we pick hash functions at random. However, universality fails to ensure that all hash functions are well behaved. We further require regularity: when picking data objects at random they should have a low probability of having the same hash value, for any fixed hash function. We present the efficient implementation of a family of non-cryptographic hash functions (PM+) offering good running times, good memory usage as well as distinguishing theoretical guarantees: almost universality and component-wise regularity. On a variety of platforms, our implementations are comparable to the state of the art in performance. On recent Intel processors, PM+ achieves a speed of 4.7 bytes per cycle for 32-bit outputs and 3.3 bytes per cycle for 64-bit outputs. We review vectorization through SIMD instructions (e.g., AVX2) and optimizations for superscalar execution.Comment: accepted for publication in Software: Practice and Experience in September 201