Notions, Definitions, and Models

In this chapter, we briefly revisit important knowledge including the cryptographic notions, algorithms, and security models of digital signatures, public-key encryption, and identity-based encryption. For convenience in the presentation, we split the traditional key generation algorithm of digital signatures and public-key encryption into the system parameter generation algorithm and the key generation algorithm, where the system parameters can be shared by all users. Each cryptosystem in this book is composed of four algorithms.