A novel group signature scheme without one way hash

The group signatures scheme was introduced by Chaum and van Heijst which allow members of a group to sign messages anonymously on behalf of the whole group. Only a designated Group Manager is able to trace the identify of the group member who issued a valid signature. The group members sign a message with their secret key gsk and produce a signature that cannot be linked to the identities of the signers without the secret key of the manager. The group manager can open the signature to recover the identities of the signers in case of any legal dispute. Group signatures have been widely used in Electronic markets where the sellers are the group members, the buyers are the veriers and the market administrator is the group manager. We aim to propose a group signature scheme that is devoid of any one-way hash function and is based upon the Integer Factorization Problem (IFP). The scheme uses the concept of safe primes to further enhance the security of the scheme. The scheme supports message recovery and hence the overload of sending the message is avoided. The scheme satisfies security properties such as Anonymity (The verier cannot link a signature to the identity of the signer), Traceability (The Group Manager can trace the identity of the signer of any valid signature), Unforgeability (A valid signature cannot be produced without the group secret keys), Exculpability (Neither the GM nor any member can produce a signature on behalf of a group member)

A Blind Signature Scheme using Biometric Feature Value

Blind signature has been one of the most charming research fields of public key cryptography through which authenticity, data integrity and non-repudiation can be verified. Our research is based on the blind signature schemes which are based on two hard problems – Integer factorization and discrete logarithm problems. Here biological information like finger prints, iris, retina DNA, tissue and other features whatever its kind which are unique to an individual are embedded into private key and generate cryptographic key which consists of private and public key in the public key cryptosystem. Since biological information is personal identification data, it should be positioned as a personal secret key for a system. In this schemes an attacker intends to reveal the private key knowing the public key, has to solve both the hard problems i.e. for the private key which is a part of the cryptographic key and the biological information incorporated in it. We have to generate a cryptographic key using biometric data which is called biometric cryptographic key and also using that key to put signature on a document. Then using the signature we have to verify the authenticity and integrity of the original message. The verification of the message ensures the security involved in the scheme due to use of complex mathematical equations like modular arithmetic and quadratic residue as well

Primality test via quantum factorization

We consider a probabilistic quantum implementation of a variation of the Pocklington-Lehmer N-1 primality test using Shor's algorithm. \mbox{O}((\log N)^3 \log\log N \log\log\log N ) elementary q-bit operations are required to determine the primality of a number N, making it (asymptotically) the fastest known primality test. Thus, the potential power of quantum mechanical computers is once again revealed