Fuzzy Identity-Based Key-Insulated Cryptosystem
Fuzzy Identity-Based Encryption (FIBE) has found many applications, such as biometric-based encryption, since its notion was firstly proposed by Sahai and Waters. In this paper, the authors show how to minimize the damage of secret key exposure in FIBE. They introduce a new notion which the authors call Fuzzy Identity-Based Key-Insulated Encryption (FIBKIE). In FIB-KIE, the secret key associated with an identity is shared between the user and a tamper-proof device. The master key is stored on a tamper-proof device and a temporary secret key used to perform cryptographic operations is stored in an insecure device and updated regularly with the help of a tamper-proof device that stores a master key.