Efficient Quantum Key Distribution

Ardehali, Mohammed ; Brassard, Gilles ; Chau, H.F. ; Lo, Hoi-Kwong

HP Development Company

关键词: quantum cryptography;    quantum key distribution;   

RP-ID  :  HPL-98-29

学科分类：计算机科学（综合）

美国|英语

来源: HP Labs

【 摘 要 】

We devise a simple modification that essentially doubles the efficiency of a well-known quantum key distribution scheme proposed by Bennett and Brassard (BB84). Our scheme assigns significantly different probabilities for the different polarisation bases during both transmission and reception to reduce the fraction of discarded data. The actual probabilities used in the scheme are announced in public. As the number of transmitted signals increases, the efficiency of our scheme can be made to approach 100%. An eavesdropper may try to break such a scheme by eavesdropping mainly along the predominant basis. To defeat such an attack, we perform a refined analysis of accepted data: instead of lumping all the accepted data together to estimate a single error rate, we separate the accepted data into various subsets according to the basis employed and estimate an error rate for each subset individually. 12 Pages