Maintaining privacy for transactions performable by a user device having a security module

摘要

A method and system for maintaining privacy for transactions performable by a user device having a security module with a privacy certification authority and a verifier are disclosed. The system includes an issuer providing an issuer public key; a user device having a security module for generating a first set of attestation-signature values; a privacy certification authority computer for providing an authority public key and issuing second attestation values; and a verification computer for checking the validity of the first set of attestation signature values with the issuer public key and the validity of a second set of attestation-signature values with the authority public key, the second set of attestation-signature values being derivable by the user device from the second attestation values, where it is verifiable that the two sets of attestation-signature values relate to the user device.