Private information escrow bound to multiple conditions

Abstract

We propose two variants of a protocol that provides users' private information escrow capability bound to multiple set of conditions in a federated single sign-on environment using trusted platform module (TPM) and secure processor technologies. The first variant assumes the existence of a trusted anonymity revo-cation manager, while the second variant does not. Cryptographic techniques, such as identity-based re-encryption and custodian-hiding encryption, are ap-plied in our protocol. A performance analysis of our protocol is provided to show that our protocol achieves a better performance in comparison to the existing anonymous credential approach. This is es-pecially true when a user interacts with many service providers in a session. The security properties pro-vided by both variants of our protocol are discussed.