Chaotic Map Based Research On Hash Algorithm

With development of information technology and increasing frequency of information exchange, the research on information security engineering becomes more and more important. As a novel technology in cryptography, digital chaotic cipher has attracted researcher dense interest and been studied widely. Chaos, as a kind of nonlinear phenomenon, has many remarkable characteristics, such as pseudo-random, unpredictability of evolution of its orbits, properties of sensitivity to initial conditions and system parameters. These characteristics are in accordance with the requirements of cryptography.This paper introduces the development, rudimentary and relevant knowledge of chaos theory firstly. The relationship between chaos and cryptography is discussed in detail through the point view of chaotic stream cipher and chaotic block cipher. We focus on chaos Hash algorithm and chaotic cipher based on searching and imaging encryption of chaos. The main contribution is as follows: a new Hash function is constructed, and the advantages of the proposed Hash function are analyzed when chaotic map is used in one-way hash function, and the construction of one-way hash function based on Logistic map, which fulfills 128bit Hash of original one-way Hash of free length, is proposed. Through detailed analysis, the construction illustrates uncomplicated, highly sensitivity to initial conditions, and has excellent property of one-way Hash function.Since identity authentication is the gateway of a secure network system, the information security experts bring forward the technology of One-time Password Authentication in order to keep password away from detecting and transmission leaking. As an application of data encryption technology in network security, an improved One-time Password Authentication Scheme based on modern cryptology is proposed in this paper.In order to embody the superiority of this scheme, first of all, this paper describes the classical one-time password authentication scheme (S/KEY authentication scheme), then points out its security flaws. Thus, based on the Challenge/Response system and depending on the safe one-way Hash function, the novel scheme is designed, which can be applied in the network environment effectively. Since the mutual conversation key is produced, the security requirement of channel in which the key is transmitted is decreased. The security of the channel is increased by using different communicating key in each authentication process. This scheme can implement the two-way identity authentication. The expense of server is cut down by producing a random data in the clients. This scheme conquers the flaws of traditional Challenge/Response system, protects the customer's ID information effectively, and can avoid some common attacks such as replay attack, mini number attack, imitate attack and etc.The innovation in this paper is using key exchange mechanism to produce the mutual key, and using different key to encrypt the transmitted data in every authentication process. Thus, a new one-time password authentication design is proposed. This scheme has an excellent performance and an extreme increase of security as well.