Alexander Ling, Antia Lamas, Ilja Gerhardt and Christian Kurtsiefer
Quantum cryptography is the oldest and best developed application of the field of quantum information science. Although it is frequently perceived as an encryption method, it is really a scheme to securely distribute correlated random numbers between the communicating parties and thus better described as quantum key distribution (QKD). Any attempt at eavesdropping from a third party is guarantied to be detected by the laws of physics (quantum mechanics) and shows up as an increased error rate in the transmission (the QBER).