🤖 AI Summary
本文解决了大域子集谓词加密方案中CCA安全性和密文及密钥大小问题，提出首个具有常量大小密文和密钥的大域CCA安全子集谓词加密方案。
📝 Abstract
Katz et al. (CANS'17) introduced Subset Predicate Encryption (SPE).
This scheme is a generalization of broadcast encryption as it emulates the \emph{subset containment} predicate in the encrypted domain.
They proposed two selectively IND-CPA secure SPE constructions in the small universe setting.
They also showed some black-box transformations of SPE to well-known primitives like WIBE and ABE to establish the richness of the SPE structure.
Chatterjee and Mukherjee (RSA'19) proposed two SPE constructions in the large-universe setting.
Their first construction achieved constant-size ciphertexts and secret keys, but it is proven secure in a restricted version of selective security.
Although the second construction achieves adaptive security, the ciphertext size depends on the size of the data-attribute set.
Furthermore, neither of these two constructions achieves CCA security.
In this work, we propose the first large-universe CCA-secure subset predicate encryption with constant-size ciphertext and secret keys.
We prove this construction achieves standard selective security under the standard subgroup decision problems.
Finally, we transform our extremely efficient SPE into the first CCA-secure WIBE, WKD-IBE, etc., with constant-size ciphertexts and secret keys via black-box transformations.