Secure Anonymous Signature-Based Transactions

Electronic commerce protocols often require users to reveal their identities and other information not necessary for reasons of security. Some applications such as contract signing are often argued to require a signer's authenticated identity; but this authentication may give the recipient a false feeling of security if certificate registration procedures do not guarantee a mapping to a liable person or the correctness of certificate data. In this paper, we propose a separation of identity from liability. Liability-aware certificates allow certificate issuers to make explicit which liabilities it accepts with respect to the transaction, the certificate data or the signer's identity. We illustrate their use in the design of a pseudonym service that provides pseudonym certificates for secure anonymous transactions.

Keywords: anonymity, pseudonymity, privacy, liability, certification.