Experimental Quantum Cryptography based on the BB84 Protocol

Main Article Content

S. Deachapunya
S. Chiangga
H. Weinfurter

Abstract

Quantum cryptography is a new technique that provides verifiable secure key exchange between the sender and the receiver. The security of the quantum cryptographic system is protected by the laws of quantum physics, which ensure that any eavesdropping can always be detected. This is in strong contrast with classical key exchange, where the security depends on (unprovable) assumptions. Recent experimental implementation of quantum cryptography achieved about 50 km point-to-point key exchange over optical fibers and about 1 km over a free space connection in daylight. Here we report the development of experimental free space quantum cryptographic systems based on the BB84 protocol. Our system does not use any active manipulation elements, resulting in compactness, reliability and easy handling.


Keywords:  quantum cryptography, quantum information


Corresponding author: E-mail: cast@kmitl.ac.th

Article Details

Section
Original Research Articles

References

[1] Charles H. Bennett and Gilles Brassard. Quantum cryptography: Public key distribution and coin tossing. pp. 175-179, December 10-12, 1984. Proceedings of the International Conference on Computers, Systems & Signal Processing, Bangalore, India.
[2] Charles H. Bennett and Gilles Brassard. An update on quantum cryptography. In G.R. Blakley and D.C. Chaum, editors, CRYPT084, pp. 475-480. Springer, 1985. Lecture Notes in Computer Science No.196.
[3] Gilles Brassard, Charles H. Bennett and Arthur K. Eckert. Quantum cryptography. Scientific American, pp. 26-33, October 1992.
[4] Richard J. Hughes et al., Secure communications using quantum cryptography, SPIE Proceedings 3076, 2(1997).