Device-independent security of quantum cryptography against collective attacks.
We present the optimal collective attack on a quantum key distribution protocol in the "device-independent" security scenario, where no assumptions are made about the way the quantum key distribution devices work or on what quantum system they operate. Our main result is a tight bound on the Holevo information between one of the authorized parties and the eavesdropper, as a function of the amount of violation of a Bell-type inequality.
ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.
Antonio
A
Acín
Nicolas
N
Brunner
Nicolas
N
Gisin
Serge
S
Massar
Stefano
S
Pironio
Valerio
V
Scarani