[PDF] A New Paradigm for Individuals in the Information Age | Semantic Scholar

It turns out that many-time restrictive blind signatures meet the specification, and a first implementation of this new class of signature schemes is presented, which uses no hash function, is about half as efficient as previous one-time restricted blind signatures and its security rests on a similar assumption as selective unforgeability of the pure ElGamal signature scheme.

This work presents the first efficient cryptographic solution that prevents transfer of personal credentials under reasonable biometric assumptions, allows to use credentials arbitrarily often, and protects the individuals’ privacy unconditionally.

The notions of existential and universal untraceability are defined and the access to the communication channels from a set of oracles are modeled and it is shown that this formalisation fits the problem being considered and allows a formal analysis of the protocols in terms of traceability.