Practical aspects of quantum cryptographic key distribution

Performance of various experimental realizations of quantum cryptographic p rotocols using polarization or phase coding are compared, including a new s elf-balanced interferometric setup using Faraday mirrors. The importance of detector noise is illustrated and means of reducing it are presented. Maxi mal distances and bit rates achievable with present day technologies are ev aluated. Practical eavesdropping strategies taking advantages of the optica l fiber that could open a gate into the transmitter's and receiver's office s are discussed.