New directions in cryptography

Abstract

In Distributed environment authentication and keyexchange mechanisms plays a major role. Generally in authentication a client and server agree upon a cryptographic key which is mutually exchanged. Earlier passwords were stored in a single server where if an intruder gains access of that server by some malicious attacks then all the passwords stored in the database are to be compromised and therefore the e-commerce application security is endangered. In-order to improve the efficiency and performance of the authentication mechanisms we involve multiple servers to store the passwords and participate in key-exchange and authentication process so as to ensure that even a single server is compromised the whole system's security is not in threat and also generating a nonce values randomly for every session corresponds to a two level security mechanism where the scope of an attacker to pretend as the legitimate user and login into the system is completely restricted.In this model the passwords are stored in their equivalent hash values and they are spitted into multiple servers. Making it even more difficult for the attacker to determine the password even by reverse engineering he cannot intercept the actual password form segments of hash value. Hence, we can present this model as safe and secure password based authentication scheme using key exchange mechanism.

An Iteration Obfuscation Based on Instruction Fragment Diversification and Control Flow Randomization

“…The first obfuscation was proposed by Diffie and Hellman [9] when they did not use the obfuscation word to describe the technique. Collberg et al introduced the technique to protect Java code program.…”

DP5: A Private Presence Service

“…This key can be computed through a Diffie-Hellman key agreement [23], assuming Alice and Bob can each learn discover each other's public key. An appropriate key derivation function can be used to extract K ab and a different K ba .…”

ID-Based Non-Interactive Universal Designated Verifier Signature for Privacy-Preserving Applications

“…The first public key system was introduced by Diffie and Hellman [1] in 1976. Such a cryptosystem provides two important mechanisms, i.e., encryption and digital signatures [1]- [5].…”

“…Such a cryptosystem provides two important mechanisms, i.e., encryption and digital signatures [1]- [5]. The former ensures confidentiality while the latter guarantees integrity, authenticity [6] and non-repudiation [7].…”