Efficient Identification Schemes Using Two Prover Interactive Proofs

We present two efficient identification schemes based on the difficulty of solving the subset sum problem and the circuit satistiabiity problem. Both schemes use the two prover model introduced by [BGKW], where the verifier (e.g the Bank) interacts with two untrusted provers (e.g two bank identification cards) who have joiitly agreed on a strategy to convince the verifier of their identity. To b&eve the validity of their identity proving procedure, the verifier must make sure that the two provers can not communicate with each other during the course of the proof process. In addition to the simplicity and efficiency of the schemes, the resulting two prover interactive proofs can be shown to be perfect zero knowledge, making no intractability assumptions.