An Attribute-Based Encryption Scheme Secure against Malicious KGC
Guoyan Zhang, Lei Liu, Yang Liu · 2012
Different from identity-based encryption scheme, an attribute-based encryption scheme is a scheme in which each user is identified by a set of attributes, and some function of those attributes is used to determine decryption ability for each ciphertext. But key escrow problem is also the inherent problem in attribute-based encryption scheme. To avoid the problem of key escrow, this paper presents an attribute-based encryption scheme by use of another secret key that the KGC cannot obtain. Following, based on a concrete attribute-based encryption scheme insecure against malicious KGC, we give a scheme secure against malicious KGC. Furthermore, compared with the original scheme, our scheme doesn't increase the length of the public key and the ciphertext. The security of our scheme is obtained directly from the security of the original scheme.