In 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.Category / Keywords: foundations / quantum cryptography Original Publication (in the same form): IACR-EUROCRYPT-2013 Date: received 24 Mar 2015 Contact author: serge fehr at cwi nl Available format(s): PDF | BibTeX Citation Version: 20150325:124418 (All versions of this report) Short URL: ia.cr/2015/277 Discussion forum: Show discussion | Start new discussion