Non-malleable non-interactive zero knowledge and adaptive chosen-ciphertext security

2003 ◽  
Author(s):  
A. Sahai
Keyword(s):  
Zero Knowledge ◽  
Chosen Ciphertext Security ◽  
Adaptive Chosen Ciphertext Security

New technique for chosen-ciphertext security based on non-interactive zero-knowledge

2019 ◽  
Vol 490 ◽  
pp. 18-35
Author(s):  
Minhye Seo ◽  
Michel Abdalla ◽  
Dong Hoon Lee ◽  
Jong Hwan Park
Keyword(s):  
New Technique ◽  
Zero Knowledge ◽  
Chosen Ciphertext Security

scholarly journals Revisiting NIZK-Based Technique for Chosen-Ciphertext Security: Security Analysis and Corrected Proofs

2021 ◽  
Vol 11 (8) ◽  
pp. 3367
Author(s):  
Youngkyung Lee ◽  
Dong Hoon Lee ◽  
Jong Hwan Park
Keyword(s):  
Recent Work ◽  
Security Analysis ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Previous Method ◽  
Zero Knowledge ◽  
Conversion Method ◽  
Security Proof ◽  
Chosen Ciphertext Security ◽  
Proof Strategy

Non-interactive zero-knowledge (NIZK) proofs for chosen-ciphertext security are generally considered to give an impractical construction. An interesting recent work by Seo, Abdalla, Lee, and Park (Information Sciences, July 2019) proposed an efficient semi-generic conversion method for achieving chosen-ciphertext security based on NIZK proofs in the random oracle model. The recent work by Seo et al. demonstrated that the semi-generic conversion method transforms a one-way (OW)-secure key encapsulation mechanism (KEM) into a chosen-ciphertext secure KEM while preserving tight security reduction. This paper shows that the security analysis of the semi-generic conversion method has a flaw, which comes from the OW security condition of the underlying KEM. Without changing the conversion method, this paper presents a revised security proof under the changed conditions that (1) the underlying KEM must be chosen-plaintext secure in terms of indistinguishability and (2) an NIZK proof derived from the underlying KEM via the Fiat–Shamir transform must have the properties of zero-knowledge and simulation soundness. This work extended the security proof strategy to the case of identity-based KEM (IBKEM) and also revise the security proof for IBKEM of previous method by Seo et al. Finally, this work gives a corrected security proof by applying the new proofs to several existing (IB)KEMs.

Publicly auditable conditional blind signatures

2021 ◽  
Vol 29 (2) ◽  
pp. 229-271
Author(s):  
Panagiotis Grontas ◽  
Aris Pagourtzis ◽  
Alexandros Zacharakis ◽  
Bingsheng Zhang
Keyword(s):  
Proof Of Concept ◽  
Equivalence Test ◽  
Zero Knowledge ◽  
Private Key ◽  
Blind Signatures ◽  
Cryptographic Primitive ◽  
Security Properties ◽  
Designated Verifier

This work formalizes Publicly Auditable Conditional Blind Signatures (PACBS), a new cryptographic primitive that allows the verifiable issuance of blind signatures, the validity of which is contingent upon a predicate and decided by a designated verifier. In particular, when a user requests the signing of a message, blinded to protect her privacy, the signer embeds data in the signature that makes it valid if and only if a condition holds. A verifier, identified by a private key, can check the signature and learn the value of the predicate. Auditability mechanisms in the form of non-interactive zero-knowledge proofs are provided, so that a cheating signer cannot issue arbitrary signatures and a cheating verifier cannot ignore the embedded condition. The security properties of this new primitive are defined using cryptographic games. A proof-of-concept construction, based on the Okamoto–Schnorr blind signatures infused with a plaintext equivalence test is presented and its security is analyzed.

scholarly journals An access control model for the Internet of Things based on zero-knowledge token and blockchain

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Lihua Song ◽  
Xinran Ju ◽  
Zongke Zhu ◽  
Mengchen Li
Keyword(s):  
Internet Of Things ◽  
Access Control ◽  
Single Point ◽  
Control Model ◽  
Third Party ◽  
Security Level ◽  
Zero Knowledge ◽  
Access Control Model ◽  
Test Analysis ◽  
Zero Knowledge Proof

AbstractInformation security has become a hot topic in Internet of Things (IoT), and traditional centralized access control models are faced with threats such as single point failure, internal attack, and central leak. In this paper, we propose a model to improve the access control security of the IoT, which is based on zero-knowledge proof and smart contract technology in the blockchain. Firstly, we deploy attribute information of access control in the blockchain, which relieves the pressure and credibility problem brought by the third-party information concentration. Secondly, encrypted access control token is used to gain the access permission of the resources, which makes the user's identity invisible and effectively avoids attribute ownership exposure problem. Besides, the use of smart contracts solves the problem of low computing efficiency of IoT devices and the waste of blockchain computing power resources. Finally, a prototype of IoT access control system based on blockchain and zero-knowledge proof technology is implemented. The test analysis results show that the model achieves effective attribute privacy protection, compared with the Attribute-Based Access Control model of the same security level, the access efficiency increases linearly with the increase of access scale.

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