Quantum computation and quantum information
Quantum computation and quantum information
Authentication of Quantum Messages
FOCS '02 Proceedings of the 43rd Symposium on Foundations of Computer Science
FOCS '00 Proceedings of the 41st Annual Symposium on Foundations of Computer Science
Universal classes of hash functions (Extended Abstract)
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
Encryption against Storage-Bounded Adversaries from On-Line Strong Extractors
Journal of Cryptology
Quantum Information & Computation
The universal composable security of quantum key distribution
TCC'05 Proceedings of the Second international conference on Theory of Cryptography
Universally composable privacy amplification against quantum adversaries
TCC'05 Proceedings of the Second international conference on Theory of Cryptography
Journal of the ACM (JACM)
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Assuming an insecure quantum channel and an authenticated classical channel, we propose an unconditionally secure scheme for encrypting classical messages under a shared key, where attempts to eavesdrop the ciphertext can be detected. If no eavesdropping is detected, we can securely re-use the entire key for encrypting new messages. If eavesdropping is detected, we must discard a number of key bits corresponding to the length of the message, but can re-use almost all of the rest. We show this is essentially optimal. Thus, provided the adversary does not interfere (too much) with the quantum channel, we can securely send an arbitrary number of message bits, independently of the length of the initial key. Moreover, the key-recycling mechanism only requires one-bit feedback. While ordinary quantum key distribution with a classical one time pad could be used instead to obtain a similar functionality, this would need more rounds of interaction and more communication.