Abstract

Quantum cryptography is a technique for establishing a fundamentally secure key for cryptography using the encoding of the key on single photon states in such a way that an eavesdropper cannot acquire any information about the key without impairing detectable errors in the communication channel [1]. In the recent years there has been a remarkable progress in experimental implementations at 850 nm and 1300 nm wavelengths with secret key generation at kbits/s up to 48 km distance. However, for 1550 nm wavelength, where fiber losses are as smallest, progress has been hampered by the lack of good single photon detectors.

© 1998 IEEE