Lattice-based autonomous path proxy re-encryption in the standard model

Autonomous path proxy re-encryption (AP-PRE) is a type of PRE that implements control on the delegation path in a multi-hop PRE. AP-PRE forces the proxy to perform the transformation along a predefined path without revealing the underlying plaintext. There are several applications of AP-PRE, including electronic medical systems, data sharing, and email systems. However, as far as we know, the existing AP-PRE scheme is provably secure in the random oracle model under the classical number-theoretic assumption, which might be vulnerable to quantum computers. Therefore, it raises the intriguing question of how to construct a quantum-resistant AP-PRE scheme. In this study, we proposed an AP-PRE scheme based on the widely accepted quantum-resistant learning with errors (LWE) assumptions. Our scheme supports the polynomial length of the delegation path. Furthermore, our scheme is proved to be selective-path CPA (sCPA) secure in the standard model under LWE assumptions.