Matrix Access structure Policy used in Attribute-Based Proxy Re-encryption
This work addresses the need for more flexible and secure access control in encrypted data sharing for cloud or proxy-based systems, representing an incremental improvement over existing CP-AB-PRE schemes.
The paper tackles the problem of enhancing ciphertext policy attribute-based proxy re-encryption by proposing a new scheme based on LSSS matrix access structures, which retains key properties like unidirectionality and multi-use while allowing policy modifications by the proxy.
Proxy re-encryption (PRE) allows a semi-trusted proxy to convert a ciphertext originally intended for Alice into an encryption of the same message intended for Bob. Song Luo, Jianbin Hu, and Zhong Chen presented a novel ciphertext policy attribute-based proxy re-encryption (CP-AB-PRE) scheme. The ciphertext policy realized in their scheme is AND-gates policy supporting multi-value attributes, negative attributes and wildcards. We propose a new access policies based on LSSS matrix access structures. Our scheme still have the properties of both PRE and CP-AB-PRE, such as unidirectionality, non-interactivity, multi-use, allows the encryptor to decide whether the ciphertext can be re-encrypted and allows the proxy to add access policy. Furthermore, our scheme can be modified to outsource the policy of W2.