Research on Information-Theoretically Composable Security for Cryptographic Primitives

在这个研究项目中，我们研究了具有信息论组合安全性的密码原语。在这里，信息论可组合安全性意味着不依赖于任何计算模型的强安全性，并且具有这种安全性的密码原语可以与其他密码原语组合而不会失去它们的安全性。本研究的主要贡献是显示信息理论的组合安全和传统的信息理论的安全的密码原语，如加密，密钥协商，认证码的本质等价性。这一结果意味着具有传统信息论安全性的密码原语可以与其他原语组合而不会在信息社会的各种复杂系统中失去安全性，因此，我们的结果不仅从理论方面而且从实用的角度来看都被认为是重要的。

In this research project, we studied cryptographic primitives having information-theoretic composable security. Here, information-theoretic composable security implies the strong security which does not depend on any computational model, and cryptographic primitives having such a security can be composed with other ones without losing their security. The main contribution of this research is to show the essential equivalence of information-theoretic composable security and traditional information-theoretic security for cryptographic primitives such as encryption, key-agreement, and authentication codes. This result means that the cryptographic primitives having traditional information-theoretic security can be composed with other ones without losing security in various and complicated systems in information society, and therefore, our results are considered to be important not only from an theoretical aspect but also from a practical viewpoint.