Quantum key distribution with classical Bob.
Secure key distribution among two remote parties is impossible when both are classical, unless some unproven computation-complexity assumptions are made, such as the difficulty of factorizing large numbers. On the other hand, a secure key distribution is possible when both parties are quantum. What is possible when only one party (Alice) is quantum, yet the other (Bob) has only classical capabilities? We present a protocol with this constraint and prove its robustness against attacks: we prove that any attempt of an adversary to obtain information necessarily induces some errors that the legitimate users could notice.
Boyer
Michel
M
Département IRO, Université de Montréal, Montréal (Québec), Canada.
Kenigsberg
Dan
D
Mor
Tal
T