一种基于密钥回收的量子加密算法

An Efficient Quantum Cipher with Key Recycling Scheme

基于Damgard等人的密钥回收算法,提出了一种更有效的新型量子加密算法。使用通用的哈希函数来检测窃听,如果没有监测到窃听,加解密双方共享的密钥可以被安全地重复使用,否则需要抛弃并重新协商与明文等长的密钥串。在加密经典明文的同时,也为剩余未加密的明文协商密钥。当协商好的密钥量与剩余的明文相同时,就可以使用一次一密来加密从而避免反馈是否存在窃听以及重新协商密钥的过程,显著提高了加密效率。

Based on the quantum key recycling scheme, a novel efficient quantum cipher is proposed. Employing the universal hashing functions to detect eavesdropping, if there is no any eavesdropping detected, then the two parties can recycling the whole key without comprising security, otherwise a key string with the length of plaintext block has to be discarded. The keys used to encrypt the remaining plaintext block in classical one time pad are also generated to avoid the feedback on whether there exists eavesdropping during the process of quantum encryptions. Such strategy improves the efficiency of the quantum key recycling scheme greatly.