In this paper, we analyze the hash functions Dynamic SHA and Dynamic SHA2, which have been selected as first round candidates in the NIST hash function competition. These hash functions rely heavily on data-dependent rotations, similar to certain block ciphers, e.g., RC5. Our analysis suggests that in the case of hash functions, where the attacker has more control over the rotations, this appro...

In this paper we describe improvements to the techniques used to cryptanalyze SHA-0 and introduce the first results on SHA1. The results include a generic multi-block technique that uses nearcollisions in order to find collisions, and a four-block collision of SHA-0 found using this technique with complexity 2. Then, extension of this and prior techniques are presented, that allow us to find co...

In this paper I describe the construction of Dynamic SHA-2 family of cryptographic hash functions. They are built with design components from the SHA-2 family, but I use the bits in message as parameters of function G, R and ROTR operation in the new hash function. It enabled us to achieve a novel design principle: When message is changed, the calculation will be different. It makes the system ...

The acquisition of a discrete-time signal is an important part compressive sensing problem. A high-accuracyalgorithm that could bring better recovery performance often called for. In this work, two thresholding algorithms involve soft decision are proposed using the Moore-Penrose inverse. Numerical examples conducted and illustrate in optimal case, both methods consume computational time same l...

HMAC is a widely used message authentication code and a pseudorandom function generator based on cryptographic hash functions such as MD5 and SHA-1. It has been standardized by ANSI, IETF, ISO and NIST. HMAC is proved to be secure as long as the compression function of the underlying hash function is a pseudorandom function. In this paper we devise two new distinguishers of the structure of HMA...

BACKGROUND AND PURPOSE Given the challenges posed by surgical clipping, endovascular techniques have been increasingly used to treat SHA aneurysms. The purpose of this study was to assess the safety and efficacy of endovascular techniques in the treatment of SHA aneurysms. MATERIALS AND METHODS Medical charts and initial and follow-up angiograms were reviewed retrospectively for all patients ...

HMAC is a widely used message authentication code and a pseudorandom function generator based on cryptographic hash functions such as MD5 and SHA-1. It has been standardized by ANSI, IETF, ISO and NIST. HMAC is proved to be secure as long as the compression function of the underlying hash function is a pseudorandom function. In this paper we devise two new distinguishers of the structure of HMA...