Fine-grained Privately Puncturable Signatures with Adaptive Security from Lattices
Junshuai Zhang, Zhenhua Liu, Dongdong Yao · 2025
Puncturable digital signatures, enable fine-grained revocation of signing authority but typically offer security only against static adversaries. To address this limitation, this paper construct a lattice-based signature scheme that supports private puncturing and achieves adaptive security in the random oracle model. This paper design integrates a private puncturable pseudorandom function (Private PRF), which allows secure secret key updates without revealing any information about the punctured messages or their corresponding signatures. This ensures existential unforgeability under adaptive chosen message attacks. The results demonstrate the feasibility of achieving adaptively secure, privacy-preserving puncturable signatures under post-quantum assumptions.