Threshold-based identity recovery for privacy enhanced applications
Joachim Biskup, Ulrich Flegel · 2000
Privacy and accountability are potentially conicting organizational and legal requirements which can be approached by allowing users to act pseudonymously.The reidentication of pseudonyms should be bound to a legal purpose requiring accountability.Existing solutions entrust this function to third parties.Upon good cause shown, these parties perform reidentication on demand.The ability to perform reidentication should be technically bound to the actual existence of a legal purpose, which in some applications can be interpreted as the transgression of a threshold.We present an approach for constructing transaction-based pseudonyms as shares for a suitably adapted version of Shamir's cryptographic approach to secret sharing.Only if pseudonymous actions exceed a threshold specied by a predetermined purpose, can the actor's identity b e r e c o vered.