Abstract: As an unbreakable cryptography, one-time-pad cryptography is an important issue in the field of information security. However, it is very difficult to achieve this goal for the difficulties in the process of secret key generation, storage and distribution. As a novel computing paradigm based on molecule biology, DNA computing, possessing the great information storage capacity and the parallel computing ability, can be applied to the field of cryptography. Nonspecific hybridization reaction has seriously affected the encryption and decryption process. Keys are distributed by PCR. XOR operation is completed by computer and then the influence of the nonspecific hybridization reaction to encrypt and decrypt the results is effectively eliminated.

Key words: one-time-pad cryptography, DNA cryptography, Polymerase Chain Reaction（PCR）

摘要： 作为不可破译的密码，一次一密密码是信息安全领域的一个重要研究课题，但密钥生成、存储和分配时存在较大困难，使得一次一密密码很难实现。以生物分子为基础的DNA计算，因其巨大的信息存储能力和高度的并行计算能力，可用于一次一密密码。非特异性杂交反应严重影响了加密过程和解密过程，通过PCR实现密钥分配，通过电子计算机实现异或运算，有效消除了非特异性杂交反应对加密结果和解密结果的影响。

关键词: 一次一密密码, DNA密码, 聚合酶链反应