Study on the efficiency and security of information

在本研究中，我们对信息论密码学的效率和安全性进行了研究，主要结果如下。首先，在量子密钥分发协议中，我们阐明了单位信道类的最优偏振轴补偿方法。其次，我们阐明了文献中广泛使用的密钥生成方法在所谓的强安全准则意义上是不安全的。第三，在相关高斯源的密钥协商中，我们阐明了公开通信速率和密钥生成速率之间的权衡。

In this study, we investigated the efficiency and the security of information theoretic cryptography, and main results are summarized as follows. First, in the quantum key distribution protocols, we clarified the optimal polarization axis compensation method for the unital channel class. Second, we clarified that the key generation method widely used in literatures is not secure in the sense of the so-called strong security criterion. Third, in the secret key agreement from correlated Gaussian sources, we clarified the trade-off between the public communication rate and the key generation rate.