PIRSA:07060022

Approximate quantum encryption and entropic security

Dupuis, F. (2007). Approximate quantum encryption and entropic security. Perimeter Institute. https://pirsa.org/07060022

Dupuis, Frédéric. Approximate quantum encryption and entropic security. Perimeter Institute, Jun. 04, 2007, https://pirsa.org/07060022 

          @misc{ pirsa_PIRSA:07060022,
            doi = {10.48660/07060022},
            url = {https://pirsa.org/07060022},
            author = {Dupuis, Fr{\'e}d{\'e}ric},
            keywords = {Quantum Information},
            language = {en},
            title = {Approximate quantum encryption and entropic security},
            publisher = {Perimeter Institute},
            year = {2007},
            month = {jun},
            note = {PIRSA:07060022 see, \url{https://pirsa.org}}
          }

Frédéric Dupuis McGill University

DOI 10.48660/07060022
Collection
Talk Type Conference
Subject

Abstract

An approximate quantum encryption scheme uses a private key to encrypt a quantum state while leaking only a very small (though non-zero) amount of information to the adversary. Previous work has shown that while we need 2n bits of key to encrypt n qubits exactly, we can get away with only n bits in the approximate case, provided that we know that the state to be encrypted is not entangled with something that the adversary already has in his possession. In this talk I will show a generalization of this result: approximate quantum encryption requires roughly n-t bits of key, where t is a lower bound on the conditional min-entropy of the state to be encrypted given the adversary's prior knowledge. Along the way, I will introduce a quantum version of entropic security and show how the approximate quantum encryption scheme fits within this framework. This is joint work with Simon-Pierre Desrosiers.