53 research outputs found
Advances of Provable Security Techniques
Advances of Provable Security Technique
Envisioning the Future of Cyber Security in Post-Quantum Era: A Survey on PQ Standardization, Applications, Challenges and Opportunities
The rise of quantum computers exposes vulnerabilities in current public key
cryptographic protocols, necessitating the development of secure post-quantum
(PQ) schemes. Hence, we conduct a comprehensive study on various PQ approaches,
covering the constructional design, structural vulnerabilities, and offer
security assessments, implementation evaluations, and a particular focus on
side-channel attacks. We analyze global standardization processes, evaluate
their metrics in relation to real-world applications, and primarily focus on
standardized PQ schemes, selected additional signature competition candidates,
and PQ-secure cutting-edge schemes beyond standardization. Finally, we present
visions and potential future directions for a seamless transition to the PQ
era
Provably Secure Group Signature Schemes from Code-Based Assumptions
We solve an open question in code-based cryptography by introducing two
provably secure group signature schemes from code-based assumptions. Our basic
scheme satisfies the CPA-anonymity and traceability requirements in the random
oracle model, assuming the hardness of the McEliece problem, the Learning
Parity with Noise problem, and a variant of the Syndrome Decoding problem. The
construction produces smaller key and signature sizes than the previous group
signature schemes from lattices, as long as the cardinality of the underlying
group does not exceed , which is roughly comparable to the current
population of the Netherlands. We develop the basic scheme further to achieve
the strongest anonymity notion, i.e., CCA-anonymity, with a small overhead in
terms of efficiency. The feasibility of two proposed schemes is supported by
implementation results. Our two schemes are the first in their respective
classes of provably secure groups signature schemes. Additionally, the
techniques introduced in this work might be of independent interest. These are
a new verifiable encryption protocol for the randomized McEliece encryption and
a novel approach to design formal security reductions from the Syndrome
Decoding problem.Comment: Full extension of an earlier work published in the proceedings of
ASIACRYPT 201
A Survey on Exotic Signatures for Post-quantum Blockchain: Challenges and Research Directions
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
A Survey on Exotic Signatures for Post-Quantum Blockchain: Challenges & Research Directions
Blockchain technology provides efficient and secure solutions to various online activities by utilizing a wide range of cryptographic tools. In this paper, we survey the existing literature on post-quantum secure digital signatures that possess exotic advanced features and which are crucial cryptographic tools used in the blockchain ecosystem for (i) account management, (ii) consensus efficiency, (iii) empowering scriptless blockchain, and (iv) 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 which 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
A Provably Secure Group Signature Scheme from Code-Based Assumptions
We solve an open question in code-based cryptography by introducing the first provably secure group signature scheme from code-based assumptions. Specifically, the scheme satisfies the CPA-anonymity and traceability requirements in the random oracle model, assuming the hardness of the McEliece problem, the Learning Parity with Noise problem, and a variant of the Syndrome Decoding problem. Our construction produces smaller key and signature sizes than the existing post-quantum group signature schemes from lattices, as long as the cardinality of the underlying group does not exceed the population of the Netherlands ( users). The feasibility of the scheme is supported by implementation results. Additionally, the techniques introduced in this work might be of independent interest: a new verifiable encryption protocol for the randomized McEliece encryption and a new approach to design formal security reductions from the Syndrome Decoding problem
Report on evaluation of KpqC candidates
This report analyzes the 16 submissions to the Korean post-quantum cryptography (KpqC) competition
A Traceable Ring Signature Scheme based on Coding Theory
Traceable ring signatures are a variant of ring signatures which allows the identity of a user to be revealed, when it signs two different messages with respect to the same group of users. It has applications in e-voting and in cryptocurrencies, such as the well-known Monero. We propose the first traceable ring signature scheme whose security is based on the hardness of the Syndrome Decoding problem, a problem in coding theory which is conjectured to be unsolvable by both classical and quantum algorithms. To construct the scheme, we use a variant of Stern\u27s protocol and, by applying the Fiat-Shamir transform to it in an ingenious way, we obtain a ring signature that allows traceability. We prove that the resulting protocol has the standard security properties for traceable ring signatures in the random oracle model: tag-linkability, anonymity and exculpability. As far as we know, this is the first proposal for a traceable ring signature scheme in the post-quantum setting
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