Information Gain in Quantum Eavesdropping

Abstract We analyse the information obtained by an eavesdropper during the various stages of a quantum cryptographic protocol associated with key distribution. We provide both an upper and a lower limit on the amount of information that may have leaked to the eavesdropper at the end of the key distribution procedure. These limits are restricted to intercept/resend eaves-dropping strategies. The upper one is higher than has been estimated so far, and should be taken into account in order to guarantee the secrecy of the final key, which is subsequently obtained via the so-called privacy amplification.

[1]  A. D. Wyner,et al.  The wire-tap channel , 1975, The Bell System Technical Journal.

[2]  Ekert,et al.  Eavesdropping on quantum-cryptographical systems. , 1994, Physical review. A, Atomic, molecular, and optical physics.

[3]  Ueli Maurer,et al.  Secret key agreement by public discussion from common information , 1993, IEEE Trans. Inf. Theory.

[4]  N. Gisin,et al.  Experimental Demonstration of Quantum Cryptography Using Polarized Photons in Optical Fibre over More than 1 km , 1993 .

[5]  Phoenix.  Quantum cryptography without conjugate coding. , 1993, Physical review. A, Atomic, molecular, and optical physics.

[6]  Stephen Wiesner,et al.  Conjugate coding , 1983, SIGA.

[7]  Markov Ciphers,et al.  Advances in Cryptology — CRYPTO ’91 , 1991, Lecture Notes in Computer Science.

[8]  Joan Feigenbaum,et al.  Advances in Cryptology-Crypto 91 , 1992 .

[9]  Barnett,et al.  Information-theoretic limits to quantum cryptography. , 1993, Physical review. A, Atomic, molecular, and optical physics.

[10]  Dominic J. A. Welsh,et al.  Codes and cryptography , 1988 .

[11]  Richard W. Hamming,et al.  Coding and Information Theory , 1980 .

[12]  Gilles Brassard,et al.  Privacy Amplification by Public Discussion , 1988, SIAM J. Comput..

[13]  Gilles Brassard,et al.  Modern Cryptology: A Tutorial , 1989 .