arXiv subjects

Juerg Wullschleger

Publications and source records attributed to Juerg Wullschleger.

4 recordsLinked to original sources

arXiv2011

Unconditional security from noisy quantum storage

We consider the implementation of two-party cryptographic primitives based on the sole assumption that no large-scale reliable quantum storage is available to the cheating party. We construct novel protocols for oblivious transfer and bit commitment, and prove that realistic noise levels provide security even against the most general attack. Such unconditional results were previously only known in the so-called bounded-storage model which is a special case of our setting. Our protocols can be implemented with present-day hardware used for quantum key distribution. In particular, no quantum storage is required for the honest parties.

quant-ph↗

arXiv2010

Bit Commitment from Weak Non-Locality

So-called non-local boxes, which have been introduced as an idealization-in different respects-of the behavior of entangled quantum states, have been known to allow for unconditional bit commitment between the two involved parties. We show that, actually, any possible non-local correlation which produces random bits on both sides can be used to implement bit commitment, and that this holds even when the parties are allowed to delay their inputs to the box. Since a particular example is the behavior of an EPR pair, this resource allows for implementing unconditionally secure bit commitment as long as the parties cannot entangle their Qbits with any other system.

quant-ph↗

arXiv2010

Bit Commitment from Non-Signaling Correlations

Central cryptographic functionalities such as encryption, authentication, or secure two-party computation cannot be realized in an information-theoretically secure way from scratch. This serves as a motivation to study what (possibly weak) primitives they can be based on. We consider as such starting points general two-party input-output systems that do not allow for message transmission, and show that they can be used for realizing unconditionally secure bit commitment as soon as they are non-trivial, i.e., cannot be securely realized from distributed randomness only.

quant-ph↗

arXiv2006

The single-serving channel capacity

In this paper we provide the answer to the following question: Given a noisy channel and epsilon>0, how many bits can be transmitted with an error of at most epsilon by a single use of the channel?

cs.IT↗