Physics

Cryptography

Public-key cryptography

Financial cryptography

Quantum cryptography

Encryption

Quantum information

Theoretical physics

Computer science

Quantum mechanics

Computer security

Quantum

Reviews of Modern Physics

Quantum cryptography exploits principles of quantum physics for the secure processing of information. A prominent example is secure communication, i.e., the task of transmitting confidential messages from one location to another. The cryptographic requirement here is that the transmitted messages remain inaccessible to anyone other than the designated recipients, even if the communication channel is untrusted. In classical cryptography, this can usually only be guaranteed under computational hardness assumptions, e.g., that factoring large integers is infeasible. In contrast, the security of quantum cryptography relies entirely on the laws of quantum mechanics. Here we review this physical notion of security, focusing on quantum key distribution and secure communication.

Security in quantum cryptography