Simple and Tight Device-Independent Security Proofs
October 5th, 2017 ROTEM ARNON-FRIEDMAN ETH Zurich

Device-independent cryptography goes beyond quantum cryptography, providing security that holds (almost) independently of the quality of the underlying physical devices. Such protocols are based on the quantum phenomena of non-locality and the violations of Bell inequalities. The analysis of device-independent protocols is complex and so far could only be done in parameter regimes, e.g., a small amount of tolerable noise, not accessible with state-of-the-art technology. In our work, we present a new technique to prove security of device-independent cryptographic protocols. At a high level, our technique amounts to establishing a reduction to the scenario in which the untrusted device operates in an identical and independent way in each round of the protocol. This makes the proof much simpler and yields significantly better, essentially tight, quantitative results when considering general quantum adversaries, compared to what was known before. Recent experimental progress, as in loophole-free Bell test experiments, suggests that the achieved parameters are technologically accessible.

In this talk, I will explain the setting of device-independent cryptography and the main ideas and tools used in our security proof. No prior knowledge of quantum cryptography is required.

Seminar, October 5, 2017, 15:00. ICFO Seminar Room

Hosted by Antonio Acín