SQIAsignHD: SQIsignHD adaptor signature
Cryptography and Communications, vol.18, no.4, pp.1243-1279, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 18 Issue: 4
- Publication Date: 2026
- Doi Number: 10.1007/s12095-026-00912-z
- Journal Name: Cryptography and Communications
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Compendex, INSPEC, MathSciNet, zbMATH, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Page Numbers: pp.1243-1279
- Keywords: Adaptor signature, Isogeny-based cryptography, Post-quantum cryptography
- Open Archive Collection: AVESIS Open Access Collection
- Middle East Technical University Affiliated: Yes
Abstract
Adaptor signatures can be viewed as a generalized form of standard digital signature schemes by linking message authentication to the disclosure of a secret value. As a recent cryptographic scheme, they have become essential for blockchain applications, including cryptocurrencies, by reducing on-chain costs, improving fungibility, and enabling off-chain payments in payment-channel networks, payment-channel hubs, and atomic swaps. However, currently implemented adaptor signature constructions, which are based on the hardness of number-theoretic assumptions such as the discrete logarithm, are vulnerable to quantum attacks due to Shor’s algorithm. In this work, we introduce SQIAsignHD, a new quantum-resistant adaptor signature scheme based on isogenies of supersingular elliptic curves, using SQIsignHD - as the underlying signature scheme - and exploiting the idea of the artificial orientation on the supersingular isogeny Diffie-Hellman key exchange protocol, SIDH, to define the underlying hard relation. We, furthermore, formally prove the security of our proposed scheme.