scholarly journals A Private Quantum Bit String Commitment

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 272 ◽  
Author(s):  
Mariana Gama ◽  
Paulo Mateus ◽  
André Souto
Keyword(s):  
Random Oracle Model ◽  
Random Oracle ◽  
Additional Property ◽  
Physical Unclonable Functions ◽  
Quantum Bit ◽  
Random Oracles ◽  
Man In The Middle

We propose an entanglement-based quantum bit string commitment protocol whose composability is proven in the random oracle model. This protocol has the additional property of preserving the privacy of the committed message. Even though this property is not resilient against man-in-the-middle attacks, this threat can be circumvented by considering that the parties communicate through an authenticated channel. The protocol remains secure and private (but not composable) if we realize the random oracles as physical unclonable functions (PUFs) in the so-called bad PUF model.

scholarly journals A Blockchain-Based Hierarchical Authentication Scheme for Multiserver Architecture

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Miqi Wu ◽  
Lin You ◽  
Gengran Hu ◽  
Liang Li ◽  
Chengtang Cao
Keyword(s):  
Secure Communication ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Authentication Scheme ◽  
Security Risks ◽  
Private Key ◽  
Blockchain Technology ◽  
Man In The Middle ◽  
User Revocation ◽  
Authentication Schemes

In a multiserver architecture, authentication schemes play an important role in the secure communication of the system. In many multiserver authentication schemes, the security of the mutual authentications among the participants is based on the security of the registration center’s private key. This centralized architecture can create security risks due to the leakage of the registration center’s private key. Blockchain technology, with its decentralized, tamper-proof, and distributed features, can provide a new solution for multiserver authentication schemes. In a lot of multiserver authentication schemes, users’ permission is generally controlled by the registration center (RC), but these permission control methods cannot be applied in the decentralized blockchain system. In this paper, a blockchain-based authentication scheme for multiserver architecture is proposed. Our scheme provides a hierarchical authentication method to solve the problems of user permission control and user revocation caused by no registration center. The security of our scheme is formally proved under the random oracle model. According to our analysis, our scheme is resistant to attacks such as impersonation attacks and man-in-the-middle attacks. In addition, our performance analysis shows that the proposed scheme has less computation overhead.

scholarly journals On Pseudo-Random Oracles

2012 ◽  
Vol 53 (1) ◽  
pp. 155-187
Author(s):  
Michal Rjaško
Keyword(s):  
Hash Function ◽  
Random Function ◽  
Hash Functions ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Public Image ◽  
Signature Schemes ◽  
Random Oracles ◽  
Random Behavior ◽  
Domain Extension

ABSTRACT Many cryptographic systems which involve hash functions have proof of their security in a so called random oracle model. Behavior of hash functions used in such cryptographic systems should be as close as possible to the behavior of a random function. There are several properties of hash functions dealing with a random behavior. A hash function is pseudo-random oracle if it is indifferentiable from a random oracle. However, it is well known that hash functions based on the popular Merkle-Damg˚ard domain extension transform do not satisfy the pseudo-random oracle property. On the other hand no attack is known for many concrete applications utilizing Merkle-Damg˚ard hash functions. Hence, a weakened notion called public-use pseudo random oracle was introduced. The property can be met by the Merkle-Damg˚ard construction and is sufficient for several important applications. A hash function is public use pseudo-random oracle if it is indifferentiable from a random oracle with public messages (i.e., all messages hashed so far are available to all parties). This is the case of most hash based signature schemes. In this paper we analyze relationship between the property pseudo-random oracle and its variant public image pseudo-random oracle. Roughly, a hash function is public image pseudo-random oracle if it is indifferentiable from a random oracle with public images (i.e., all images of messages hashed so far are available to all parties, messages are kept secret). We prove that the properties are equivalent.

scholarly journals Attacks on One Designated Verifier Proxy Signature Scheme

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Baoyuan Kang
Keyword(s):  
Standard Model ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Proxy Signature ◽  
Signature Scheme ◽  
Signature Schemes ◽  
Random Oracles ◽  
The Standard Model ◽  
New Construction ◽  
Designated Verifier

In a designated verifier proxy signature scheme, there are three participants, namely, the original signer, the proxy signer, and the designated verifier. The original signer delegates his or her signing right to the proxy signer, then the proxy signer can generate valid signature on behalf of the original signer. But only the designated verifier can verify the proxy signature. Several designated verifier proxy signature schemes have been proposed. However, most of them were proven secure in the random oracle model, which has received a lot of criticism since the security proofs in the random oracle model are not sound with respect to the standard model. Recently, by employing Water's hashing technique, Yu et al. proposed a new construction of designated verifier proxy signature. They claimed that the new construction is the first designated verifier proxy signature, whose security does not rely on the random oracles. But, in this paper, we will show some attacks on Yu et al.'s scheme. So, their scheme is not secure.

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

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.

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

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.

Tighter Security Proofs for GPV-IBE in the Quantum Random Oracle Model

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Shuichi Katsumata ◽  
Shota Yamada ◽  
Takashi Yamakawa
Keyword(s):  
Random Oracle Model ◽  
Random Oracle ◽  
Security Proofs

Tighter Proofs of CCA Security in the Quantum Random Oracle Model

2019 ◽  
pp. 61-90 ◽  
Author(s):  
Nina Bindel ◽  
Mike Hamburg ◽  
Kathrin Hövelmanns ◽  
Andreas Hülsing ◽  
Edoardo Persichetti
Keyword(s):  
Random Oracle Model ◽  
Random Oracle
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