Anonymous Identity Based Encryption with Traceable Identities
Olivier Blazy, Laura Brouilhet, Duong Hieu Phan · 2019
We introduce Anonymous Identity Based Encryption with Traceable Identities, in which we provide a new feature to anonymous identity-based encryption schemes: lifting the anonymity of some specific recipients in necessary situations (such as when they are suspected as criminals). Our primitive allows a tracer, given a tracing key associated to an identity, to filter all the ciphertexts that are sent to this specific identity (and only those). As it is primordial to preserve the privacy of the law-abiding users, the security takes into account the collusion of tracers and corrupted users.