IACR News item: 25 March 2015
Marco Tomamichel, Serge Fehr, J\\k{e}drzej Kaniewski, Stephanie Wehner
ePrint ReportIn this work, we show that the standard BB84 QKD scheme is one-sided device-independent. This means that security holds even if Bob\'s quantum device is arbitrarily malicious, as long as Alice\'s device behaves as it should. Thus, we can completely remove the trust into Bob\'s quantum device for free, without the need for changing the scheme, and without the need for hard-to-implement loophole-free violations of Bell inequality, as is required for fully (meaning two-sided) device-independent QKD.
For our analysis, we introduce a new quantum game, called a monogamy-of-entanglement game, and we show a strong parallel repetition theorem for this game. This new notion is likely to be of independent interest and to find additional applications. Indeed, besides the application to QKD, we also show a direct application to position-based quantum cryptography: we give the first security proof for a one-round position-verification scheme that requires only single-qubit operations.
Additional news items may be found on the IACR news page.