Impossibility on the Schnorr Signature from the One-more DL Assumption in the Non-programmable Random Oracle Model

Optimistic Fair Exchange protocol was designed for two parties to exchange in a fair way where an arbitrator always remains offline and will be referred only if any dispute happens. There are various optimistic fair exchange protocols with different security properties in the literature. Most of the optimistic fair exchange protocols satisfy resolution ambiguity where a signature signed by the signer is computational indistinguishable from the one resolved by the arbitrator. Huang et al. proposed the first generic framework for accountable optimistic fair exchange protocol in the random oracle model where it possesses resolution ambiguity and is able to reveal the actual signer when needed. Ganjavi et al. later proposed the first generic framework in the standard model. In this paper, we propose a new generic framework for accountable optimistic fair exchange protocol in the standard model using ordinary signature, convertible undeniable signature, and ring signature scheme as the underlying building blocks. We also provide an instantiation using our proposed generic framework to obtain an efficient pairing-based accountable optimistic fair exchange protocol with short signature.

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Fuzzy Identity-Based Ring Signature from Lattices

Security and Communication Networks ◽

10.1155/2021/6692608 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Chengtang Cao ◽

Lin You ◽

Gengran Hu

Keyword(s):

Large Scale ◽

Quantum Computer ◽

Random Oracle Model ◽

Random Oracle ◽

Small Integer ◽

Ring Signature ◽

Computer Attacks ◽

Identity Based ◽

The One ◽

Fuzzy Identity

In this paper, a construction of a fuzzy identity-based ring signature scheme (LFIBRS) is proposed. Our LFIBRS combines the characteristics of both the fuzzy identity-based signature (FIBS) and the ring signature. On the one hand, a signature issued under an identity ID can be verified by any identity ID ′ that is “close enough” to the identity ID . Since biometric identification is the well-known most popular and reliable identification method, our LFIBRS can be applied in such a situation whenever it is required for official audit or supervision that the signer’s real identity is needed to be authenticated. On the other hand, LFIBRS provides anonymity under the random oracle model. In addition, LFIBRS provides unforgeability under the small integer solution (SIS) lattice hardness assumption which can resist large-scale quantum computer attacks in the future.

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An Identity-Based Blind Signature Scheme Using Lattice with Provable Security

Mathematical Problems in Engineering ◽

10.1155/2020/7528571 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Quanrun Li ◽

Chingfang Hsu ◽

Debiao He ◽

Kim-Kwang Raymond Choo ◽

Peng Gong

Keyword(s):

Quantum Computer ◽

Rapid Development ◽

Random Oracle Model ◽

Random Oracle ◽

Mean Value ◽

Blind Signature ◽

Signature Scheme ◽

Practical Applications ◽

Universal Quantum ◽

Identity Based

With the rapid development of quantum computing and quantum information technology, the universal quantum computer will emerge in the near decades with a very high probability and it could break most of the current public key cryptosystems totally. Due to the ability of withstanding the universal quantum computer’s attack, the lattice-based cryptosystems have received lots of attention from both industry and academia. In this paper, we propose an identity-based blind signature scheme using lattice. We also prove that the proposed scheme is provably secure in the random oracle model. The performance analysis shows that the proposed scheme has less mean value of sampling times and smaller signature size than previous schemes. Thus, the proposed scheme is more suitable for practical applications.

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ID-based key-insulated signcryption with equality test in cloud computing

SN Applied Sciences ◽

10.1007/s42452-021-04469-9 ◽

2021 ◽

Vol 3 (4) ◽

Author(s):

Seth Alornyo ◽

Kingsford Kissi Mireku ◽

Mustapha Adamu Mohammed ◽

Daniel Adu-Gyamfi ◽

Michael Asante

Keyword(s):

Cloud Computing ◽

Random Oracle Model ◽

Random Oracle ◽

Harsh Environments ◽

Secret Key ◽

Secret Keys ◽

Security Property ◽

Equality Test ◽

Chosen Ciphertext Attack ◽

Chosen Message Attack

AbstractKey-insulated encryption reduces the problem of secret key exposure in hostile setting while signcryption cryptosystem attains the benefits of digitally signing a ciphertext and public key cryptosystem. In this study, we merge the primitives of parallel key-insulation cryptosystem and signcryption with equality test to construct ID-based parallel key-insulated signcryption with a test for equality (ID-PKSET) in cloud computing. The construction prevent data forgery, data re-play attacks and reduces the leakage of secret keys in harsh environments. Our scheme attains the security property of existential unforgeable chosen message attack (EUF-CMA) and indistinquishable identity chosen ciphertext attack (IND-ID-CCA2) using random oracle model.

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