Patent ID: 7685125

Claim:
A method for a data provider to provide and prove an association between a first data value A and a second data value B, comprising: computing, by a computer, evidence E of an association between A and B; ensuring, by the computer, that a verifier has A, B and E; and running, by the computer, an interactive proof with the verifier to convince the verifier that the evidence is valid evidence of an association between A and B without enabling the verifier to provide proof of the validity of the evidence to a third party, wherein the evidence E is of the form E=H ( A∥B ) k*(p−1)/q mod ρ, where H is a secure hash function, k is a random number, p is a first prime, and q is a second prime, and wherein in running the interactive proof the provider convinces the verifier that the provider knows the value of k without disclosing the value of k to the verifier.