Paper 2022/272

Quantum-Secure Aggregate One-time Signatures with Detecting Functionality

Shingo Sato and Junji Shikata

Abstract

An aggregate signature (ASIG) scheme allows any user to compress multiple signatures into a short signature called an aggregate signature. While a conventional ASIG scheme cannot detect any invalid messages from an aggregate signature, an ASIG scheme with detecting functionality (D-ASIG) has an additional property which can identify invalid messages from aggregate signatures. Hence, D-ASIG is useful to reduce the total amount of signature-sizes on a channel. On the other hand, development of quantum computers has been advanced recently. However, all existing D-ASIG schemes are insecure against attacks using quantum algorithms, which we call quantum attacks. In this paper, we propose a D-ASIG scheme with quantum-security which means security in a quantum setting. Hence, we first introduce quantum-security notions of ASIGs and D-ASIGs because there is no research on such security notions for (D-)ASIGs. Second, we propose a lattice-based aggregate one-time signature scheme with detecting functionality, and prove that this scheme satisfies our quantum-security in the quantum random oracle model and the certified key model. Hence, this scheme is the first quantum-secure D-ASIG.