Design of Blind Signature Protocol Based upon DLP

Blind signature scheme is based on public key cryptosystem. Public-key cryptosystem is widely used these days for various security purposes. The use of public key cryptosystems received huge amount of attention. They are benecial in encipherment, authentication, non-repudiation as well as digital signature, which plays an essential role in electronic banking and nancial transactions. This project has proposed a new blind signature scheme based on ElGamal signature scheme. Blind signature schemes, rst introduced by David Chaum, allows a person to get a message signed by another party without revealing any information about the message to the other party. It is an extension of digital signature which can be implements using a number of common public key signing schemes, for instance RSA and ElGamal signature scheme. Blind signature is typically employed in privacy related protocols, where the signer and the requester are dierent person. In our project work we have taken an existing scheme based on ElGamal signature scheme as the reference scheme for comparison and proposed a new scheme. Aims of the proposed scheme is high security features and reduce the communication overhead, computation overhead, signature length. The proposed scheme aims to have lesser computation overhead and high security features than existing scheme [1, 2, 3, 5, 15, 16

Status of This Memo

This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards " (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2006). This document specifies how to establish secure connection-oriented media transport sessions over the Transport Layer Security (TLS) protocol using the Session Description Protocol (SDP). It defines a new SDP protocol identifier, ’TCP/TLS’. It also defines the syntax and semantics for an SDP ’fingerprint ’ attribute that identifies the certificate that will be presented for the TLS session. This mechanism allows media transport over TLS connections to b

"IMAGE DIGEST III: A NEAREST NEIGHBOUR DIFFERENTIAL BASED IMAGE DIGEST GENERATION ALGORITHM "

In this paper we present a methodology to generate a digest for an image based on the grayness value differentials that exist between neighboring pixels. Neighboring pixels are those that lie to the immediate left, immediate right, immediate above and immediate below of a given pixel plus the four pixels that lie in between. This algorithm works on the monochrome images of VGA resolution. Color images are converted to their monochrome equivalents. Images of resolution higher than VGA are converted to images of VGA resolution. The given image is divided into equal sized segments or regions. The pixels of the given image are sampled in such a way that each segment contributes equally to the sampled set for the image. This algorithm uses a histogram based statistical approach towards digest generation. Counters are maintained at the segment level, which keep the raw counts of the differentials for the sampled pixels. The counter values are composed to form the digest for the segment. Computing the digest at the segment level helps to preserve the locality information for the image. The digest for the entire image is a composition of the individual digests generated for each segment or region. The method also provides for the calculation of a lite version of the digest that saves digest space by ignoring the region or locality information

Multi-Stream Hashing on the PlayStation 3

With process technology providing more and more transistors per chip, still following Moore's \law", processor designers have used a number of techniques to make those transistors useful. Lately they have started placing multiple processor cores on each chip; an example is the Cell Broadband Engine, which serves as the heart of Sony's PlayStation 3 game console. We present high-performance multi-stream versions of cryptographic hash functions from the MD/SHA-family. Our implementations require 1.74, 3.51 and 8.18 cycles per byte per SPE when using the cryptographic hash functions MD5, SHA-1 and SHA-256 respectively. To the best of our knowledge these are the fastest implementations of these hash functions for the Cell processor. These implementations can be useful for cryptanalytic use as well as for utilizing the SPEs as cryptographic accelerators

Robustness of Affine and Extended Affine Equivalent Surjective S-Box(es) against Differential Cryptanalysis

A Feistel Network (FN) based block cipher relies on a Substitution Box (S-Box) for achieving the non-linearity. S-Box is carefully designed to achieve optimal cryptographic security bounds. The research of the last three decades shows that considerable efforts are being made on the mathematical design of an S-Box. To import the exact cryptographic profile of an S-Box, the designer focuses on the Affine Equivalent (AE) or Extended Affine (EA) equivalent S-Box. In this research, we argue that the Robustness of surjective mappings is invariant under AE and not invariant under EA transformation. It is proved that the EA equivalent of a surjective mapping does not necessarily contribute to the Robustness against the Differential Cryptanalysis (DC) in the light of Seberry\u27s criteria. The generated EA equivalent S-Box(es) of DES and other $6 \times 4$ mappings do not show a good robustness profile compared to the original mappings. This article concludes that a careful selection of affine permutation parameters is significant during the design phase to achieve high Robustness against DC and Differential Power Analysis (DPA) attacks

An improved preimage attack on MD2

This paper describes an improved preimage attack on the cryptographic hash function MD2. The attack has complexity equivalent to about $2^{73}$ evaluations of the MD2 compression function. This is to be compared with the previous best known preimage attack, which has complexity about $2^{97}$