Showing papers on "Merkle signature scheme published in 1985"

A public key cryptosystem and a signature scheme based on discrete logarithms

Abstract: A new signature scheme is proposed, together with an implementation of the Diffie-Hellman key distribution scheme that achieves a public key cryptosystem. The security of both systems relies on the difficulty of computing discrete logarithms over finite fields.

A Fast Signature Scheme Based on Quadratic Inequalities

Abstract: A new digital signature scheme is proposed in which the computation time is several hundred times faster than the RSA scheme and in which the key length and signature length are almost comparable to those for the RSA. Moreover, the scheme can be easily implemented and is, therefore, most practical for many digital signature applications. This new scheme is based on both a quadratic congruent inequality and a one-way hash function. The secret key consists of two large prime numbers p and q, and the public key is their product, n=p2q. An inequality is used for signature verification. Although the degree of security in this scheme has not been proved, it is shown that security seems to be equivalent to the difficulty of factoring a large number.

An attack on a signature scheme proposed by Okamoto and Shiraishi

Abstract: Recently Okamoto and Shiraishi proposed a public key authentication system [1]. The security of the scheme is based on the difficulty of solving quadratic inequalities. This new system is interesting since the amount of computing needed for the proposed scheme is significantly less than that needed for an RSA encryption.This report is an investigation into the security of the proposed digital signature scheme. We demonstrate that if the system is used as it is presented, an opponent could sign messages without factoring the modulus. Further, we suggest a modification which may not have the same flaw as the proposed scheme.