Software Implementation of Ciphertext-Policy Functional Encryption with Simple Usability

In traditional public key encryption schemes, data encrypted by a public key pk can be decrypted only by a secret key sk corresponding to pk, and their relation between pk and sk is static.Therefore, the schemes are unsuited for control of access to several data.Meanwhile, functional encryption (FE) is an encryption scheme that provides more sophisticated and flexible relations between pk and sk.Thus, FE enables only one pk to encrypt each one of the data with any conditions for decryption, so it is considered to be a very useful tool for the access control of data on the cloud server.However, implementing the current FE scheme is a non-trivial task because deep knowledge about the scheme is required.This is an obstacle factor to deploy the FE scheme in the real-world security systems.In this paper, we propose an implementation of the Ciphertext-Policy FE (CP-FE, a useful variant of FE) library usable even for people who do not have the deep knowledge of the CP-FE scheme.