Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Lecture notes in computer science

Post-quantum Adaptor Signatures with Strong Security from Cryptographic Group Actions

Ryann Cartor, Nathan Daly, Giulia Gaggero, Jason T. LeGrow, Andrea Sanguineti, Silvia Sconza

Published Jan 1, 2026• 0 citations
Publisher
DOI
10.1007/978-3-032-22695-2_13

Related papers

Tightly Secure Identity-Based Signature from Cryptographic Group Actions

Xuan Thanh Khuc, Willy Susilo, Dung Hoang Duong +3 more

Lecture notes in computer science•Jan 1, 2025•0 citations

Lattices, Isogenies and Adaptor Signatures in Post-Quantum Cryptography

Andrea Sanguineti

In this thesis we give an analysis of the hierarchical identity-based broadcast encryption scheme proposed by C. Yang, Zheng, Wang, Lu and Y. Yang. The interest in this scheme is due to the fact that it is one of the few of its kind to be Post-Quantum, and relies on the hardness of the LWE, i.e. on lattice-based problems. For the first time we give a detailed description of the scheme and we present a full introduction to the mathematical and cryptographic background needed to describe it. The main result of the thesis is the construction of an adaptor signature for CSI-FiSh that we called ORCAS. Cryptographic group actions are a promising technique that underlie several Post-Quantum digital signatures, including CSI-FiSh. Our proposal, ORCAS, which stands for One-Round "Cheating" Adaptor Signatures (so named because its pre-signing algorithm resembles how cheating signer might try to forge a Fiat-Shamir-based signature), is directly compatible with CSI-FiSh. While the signatures are produced in a different manner and follow a slightly different distribution, they can still be verified by a blockchain which supports only CSI-FiSh.

•Sep 15, 2026•0 citations

Post-Quantum Secure Group Signatures

Laurens Porzenheim

•Jan 1, 2019•0 citations

A Survey on Exotic Signatures for Post-quantum Blockchain: Challenges and Research Directions

Maxime Buser, Rafael Dowsley, Muhammed F. Esgin +9 more

Blockchain technology provides efficient and secure solutions to various online activities by utilizing a wide range of cryptographic tools. In this article, we survey the existing literature on post-quantum secure digital signatures that possess exotic advanced features and that are crucial cryptographic tools used in the blockchain ecosystem for (1) account management, (2) consensus efficiency, (3) empowering scriptless blockchain, and (4) privacy. The exotic signatures that we particularly focus on in this work are the following: multi-/aggregate, threshold, adaptor, blind, and ring signatures. Herein the term ”exotic” refers to signatures with properties that are not just beyond the norm for signatures, e.g., unforgeability, but also imbue new forms of functionalities. Our treatment of such exotic signatures includes discussions on existing challenges and future research directions in the post-quantum space. We hope that this article will help to foster further research to make post-quantum cryptography more accessible so that blockchain systems can be made ready in advance of the approaching quantum threats.

ACM Computing Surveys•Dec 1, 2022•47 citations

Post - Quantum Cryptography and Authentication: Enhancing Security for the Quantum Era

Nguyễn Thị Phượng Hằng, Lưu Hồng Dũng

•Jan 1, 2025•0 citations

Tanuki: New Frameworks for (Concurrently Secure) Blind Signatures from Post-Quantum Groups Actions.

Lucjan Hanzlik, Yi-Fu Lai, Marzio Mula +3 more

Blind signatures are fundamental cryptographic primitives enabling privacy-preserving authentication and have seen renewed interest in the post-quantum literature. Existing efficient constructions predominantly rely on Fischlin’s generic paradigm instantiated over lattice assumptions, while blinding techniques for Σ-protocol-based blind signatures remain sparse beyond lattices. Moreover, achieving provable concurrent security under polynomially many sessions has been a longstanding open challenge for this approach in the post-quantum literature as evidenced by the recent attacks in EC’24 and PKC’24. This work broadens the landscape of post-quantum blind signatures by introducing novel techniques and proposing four frameworks based on general cryptographic group actions, without requiring commutativity. Our constructions admit instantiations under diverse post-quantum assumptions, including CSIDH (isogeny-based), LESS (code-based, NIST round-two), and more. These frameworks offer flexible trade-offs in assumptions (from interactive one-more to the standard inversion problem) and key/signature sizes, and culminate in a construction that achieves security under polynomially many concurrent sessions. This enables the first efficient blind signatures from isogenies and codes with provable concurrent security with 4.5 and 64.7 KB respectively. We also outline several directions for optimization and further instantiations for future work.

•Jan 1, 2025•0 citations
In this thesis we give an analysis of the hierarchical identity-based broadcast encryption scheme proposed by C. Yang, Zheng, Wang, Lu and Y. Yang. The interest in this scheme is due to the fact that it is one of the few of its kind to be Post-Quantum, and relies on the hardness of the LWE, i.e. on lattice-based problems. For the first time we give a detailed description of the scheme and we present a full introduction to the mathematical and cryptographic background needed to describe it. The main result of the thesis is the construction of an adaptor signature for CSI-FiSh that we called ORCAS. Cryptographic group actions are a promising technique that underlie several Post-Quantum digital signatures, including CSI-FiSh. Our proposal, ORCAS, which stands for One-Round "Cheating" Adaptor Signatures (so named because its pre-signing algorithm resembles how cheating signer might try to forge a Fiat-Shamir-based signature), is directly compatible with CSI-FiSh. While the signatures are produced in a different manner and follow a slightly different distribution, they can still be verified by a blockchain which supports only CSI-FiSh.
Blockchain technology provides efficient and secure solutions to various online activities by utilizing a wide range of cryptographic tools. In this article, we survey the existing literature on post-quantum secure digital signatures that possess exotic advanced features and that are crucial cryptographic tools used in the blockchain ecosystem for (1) account management, (2) consensus efficiency, (3) empowering scriptless blockchain, and (4) privacy. The exotic signatures that we particularly focus on in this work are the following: multi-/aggregate, threshold, adaptor, blind, and ring signatures. Herein the term ”exotic” refers to signatures with properties that are not just beyond the norm for signatures, e.g., unforgeability, but also imbue new forms of functionalities. Our treatment of such exotic signatures includes discussions on existing challenges and future research directions in the post-quantum space. We hope that this article will help to foster further research to make post-quantum cryptography more accessible so that blockchain systems can be made ready in advance of the approaching quantum threats.
Blind signatures are fundamental cryptographic primitives enabling privacy-preserving authentication and have seen renewed interest in the post-quantum literature. Existing efficient constructions predominantly rely on Fischlin’s generic paradigm instantiated over lattice assumptions, while blinding techniques for Σ-protocol-based blind signatures remain sparse beyond lattices. Moreover, achieving provable concurrent security under polynomially many sessions has been a longstanding open challenge for this approach in the post-quantum literature as evidenced by the recent attacks in EC’24 and PKC’24. This work broadens the landscape of post-quantum blind signatures by introducing novel techniques and proposing four frameworks based on general cryptographic group actions, without requiring commutativity. Our constructions admit instantiations under diverse post-quantum assumptions, including CSIDH (isogeny-based), LESS (code-based, NIST round-two), and more. These frameworks offer flexible trade-offs in assumptions (from interactive one-more to the standard inversion problem) and key/signature sizes, and culminate in a construction that achieves security under polynomially many concurrent sessions. This enables the first efficient blind signatures from isogenies and codes with provable concurrent security with 4.5 and 64.7 KB respectively. We also outline several directions for optimization and further instantiations for future work.