Randomness Extraction via Delta-Biased Masking in the Presence of a Quantum Attacker

dc.creatorFehr, Serge
dc.creatorSchaffner, Christian
dc.date2007-06-18
dc.date2007-12-13
dc.date.accessioned2026-07-07T08:48:44Z
dc.date.available2026-07-07T08:48:44Z
dc.descriptionRandomness extraction is of fundamental importance for information-theoretic cryptography. It allows to transform a raw key about which an attacker has some limited knowledge into a fully secure random key, on which the attacker has essentially no information. Up to date, only very few randomness-extraction techniques are known to work against an attacker holding quantum information on the raw key. This is very much in contrast to the classical (non-quantum) setting, which is much better understood and for which a vast amount of different techniques are known and proven to work. We prove a new randomness-extraction technique, which is known to work in the classical setting, to be secure against a quantum attacker as well. Randomness extraction is done by XOR'ing a so-called delta-biased mask to the raw key. Our result allows to extend the classical applications of this extractor to the quantum setting. We discuss the following two applications. We show how to encrypt a long message with a short key, information-theoretically secure against a quantum attacker, provided that the attacker has enough quantum uncertainty on the message. This generalizes the concept of entropically-secure encryption to the case of a quantum attacker. As second application, we show how to do error-correction without leaking partial information to a quantum attacker. Such a technique is useful in settings where the raw key may contain errors, since standard error-correction techniques may provide the attacker with information on, say, a secret key that was used to obtain the raw key.
dc.description17 pages, v2: mainly editorial changes taking into account referee comments
dc.identifierhttps://arxiv.org/abs/0706.2606
dc.identifierhttp://arxiv.org/abs/0706.2606
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/144048
dc.subjectQuantum Physics
dc.subjectCryptography and Security
dc.titleRandomness Extraction via Delta-Biased Masking in the Presence of a Quantum Attacker
dc.typetext

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