Abstract: This article firstly identifies the most important trend in the development of information security is that finding new security issues by introducing cryptographic techniques into the field of system security, which enables that cryptographic security has been increasingly applied in almost every aspect of the computer system. Besides, we present the new characteristics of modern cryptography resulted from this new application and new types of service mode, including that the entity has been transformed from single mode to multiparty mode, the position has been transformed from local mode to remote mode, and the security model has been transformed from channel security model to “channel security plus” model. Based on the new features given above, we mainly focus on discussing both the state-of-the-art and the future directions for theorectical research in the aspects of ciphertext access control, secure outsourced comutation, secure search, electronic currency and blockchain security, and privacy-preserving in artificial intelligence and machine learning. Finally, we also introduce some application results, including the hardware development of the mobile device for encrypted data sharing and the identity authentication based on biological information.

Key words: information security, ciphertext access control, secure outsourced computation, secure search, blockchain security, privacy-preserving in artificial intelligence