PhD Application Talk: Efficient long-term secure universally composable commitments

The notion of universal composability preserves the security of a cryptographic protocol when it is used in combination with any other protocols, in possibly complex systems. The research initiated by Müller-Quade and Unruh in the area of long-term universal composability has shown the existence of secure commitments in this model, under general cryptographic assumptions without having an emphasis on the efficiency of the protocols designed. Building on their work and using very efficient zero-knowledge proofs of knowledge techniques, we present a new long-term universally composable secure commitment protocol that is both efficient and plausible to use in practice.
The efficiency of our protocol stems from the fact that it requires only thirteen modular exponentiations from the sender and eleven modular exponentiations from the recipient.