REALIZATION OF A MINIMUM-KNOWLEDGE IDENTIFICATION AND SIGNATURE SCHEME

A minimum-knowledge scheme allows a claimant to prove its identity to a verifier without disclosing any secret information. Minimum-knowledg e schemes, incorporating identity verification, signature generation a nd verification, are generally based on interactive proofs. The Ohta-O kamoto minimum-knowledge identification and signature scheme is charac terised by a good balance between the claimant's storage requirements and the time to perform a verification. This makes it particularly sui table for use with minimum storage devices such as smart cards. This p aper presents a realisation of an Ohta-Okamoto based minimum knowledge and signature scheme, ranging over identity verification, signature g eneration and verification. The modular arithmetic functions, such as: multiplication, division, exponentiation and multiplicative inverse, as well as prime number generation, pseudo random number generation an d hashing function are detailed. An analysis of the realised scheme is presented, including a comparison with the Fiat-Shamir identification scheme.