Device-independent security of quantum cryptography against collective attacks

Therefore, the purification provides a method to analyze the security of our scheme in an entanglement-based picture, where Alice makes random BB84 measurements on one half of

We have shown that explicit, fairly loss-tolerant MDI-EWs can be systematically obtained from any standard entanglement witness (and, actually, from any particular decomposition

Security is then established by virtue of a relation between the violation of this CHSH test and the incompatibility of the two possible measurements carried out by Alice’s

We show in both cases that if Alice and Bob do not share a common reference frame but measure entangled pairs of quantum systems along randomly orientated measurement bases, they

It is thus possible to determine directly from the observed correlations whether a genuinely tripartite entangled state was measured, or whether these correlations are compatible

This seems not surprising since the maximal violation has already told us that the shared state contains the maximally two-qubit entangled state and Alice’s measurements form

The main contribution of this paper is the construction of a self-testing protocol that allows a classical verifier to certify that a single computationally bounded quantum prover

3 Bounding Eve’s information with generalized CHSH tests We are now ready to compute a bound on Eve’s information as a function of the generalized CHSH score given in Eq.. 6 by