A secure anonymous authentication scheme was proposed based on elliptic curve and zero-knowledge proof,which adopts a bidirectional anonymous authentication algorithm to preserve users’ privacy during the certification process.In the case of a high density traffic scenario,a message aggregation technology was proposed to realize fast authentication by the assistant of RSU,and to avoid the loss of massive messages unauthenticated promptly.The simulation and analytical results show that the proposed scheme yields a much better performance than previously reported counterparts with lower communication overhead,message loss rate and message delay.
In many applications, when communicating with a host, we may or may not be concerned about the privacy of the data but are mainly concerned about the integrity of data being transmitted. This paper presents a simple algorithm based on zero knowledge proof by which the receiver can confirm the integrity of data without the sender having to send the digital signature of the message directly. Also, if the same document is sent across by the same user multiple times, this scheme results in different digital signature each time thus making it a practical one-time signature scheme.
Radio frequency identification has enabled exciting new prospects in wireless ID services, particularly for personnel. Unfortunately, the earliest applications relied upon acquiescent mechanisms that accepted and returned data with no intermediary processing. The advent of smart cards made possible an on-chip revolution in the use of contact identification devices. What I explore here is the extension of these embedded systems to their non-contact counterparts (namely RFID). The processing layer is of utmost importance to us in the study of privacy controls, as it opens the discussion on how personnel ID in general may evolve from storage devices that may be intercepted and duplicated into cryptographically sound logic devices that can resist common attacks and directly participate in the decisions concerning disclosure. This brings us to one of the most vital aspects of the research, the zero-knowledge proof. Frequently RFID is applied as a convenient means of answering questions about discrete state (from a comfortable distance). Wherever possible, we wish to answer those questions without compromising user privacy in the process. The integration of RFID and embedded systems allows us to perform proofs based on internal comparisons and calculations rather than irrevocable release of the data. This is the security of the embedded systems used widely in electronic commerce with the convenience of near-field communications. It holds the promise of a better all-around user experience, with better protections, more control, and easier methods of performing common objectives.
In many applications, the password is sent as cleartext to the server to be authenticated thus providing the eavesdropper with opportunity to steal valuable data. This paper presents a simple protocol based on zero knowledge proof by which the user can prove to the authentication server that he has the password without having to send the password to the server as either cleartext or in encrypted format. Thus the user can authenticate himself without having to actually reveal the password to the server. Also, another version of this protocol has been proposed which makes use of public key cryptography thus adding one more level of security to the protocol and enabling mutual authentication between the client & server.
利用Cha-Cheon 的基于身份的签名方案提出了一个可证安全的基于身份的可验证加密签名(verifiablyencrypted signature,简称VES)方案,并利用该方案和基于身份的代理可验证加密签名(proxy verifiably encryptedsignature,简称PVES)方案提出了一个新颖的多元合同签署协议.信息交换过程中,原始签名者或代理签名者分别利用VES 或PVES 实现承诺消息的交换与认证,并未使用复杂的零知识证明系统,从而有效避免了大量运算.当争议发生时,可信第三方从VES 或PVES 中恢复出有效的合同签名,以保证签署者的公平性.安全性分析结果表明,协议满足不可否认性、时效性以及公平性.;Utilizing the Cha-Cheon’s identity-based signature scheme, a provably secure identity-based verifiably encrypted signature (VES) scheme is proposed. Utilizing the proposed scheme and identity-based proxy verifiably encrypted signature (PVES) scheme, a novel multiplex contract signing protocol is also proposed. The original signer or proxy signer uses VES or PVES to realize the interaction and certification of the commitment message in the information exchange process. The proposed scheme does not need the zero-knowledge proof and excessive computation. An optimized trusted third party who participates in the protocol extracts the formal signature from the VES or PVES only when problem occurs. The performance analysis results show that the scheme satisfies non-repudiation, timeliness and fairness.
In this thesis we present two new type systems for verifying the security of cryptographic protocol models expressed in a spi-calculus and, respectively, of protocol implementations expressed in a concurrent lambda calculus. In this thesis we present two new type systems for verifying the security of cryptographic protocol models expressed in a spi-calculus and, respectively, of protocol implementations expressed in a concurrent lambda calculus. The two type systems combine prior work on refinement types with union and intersection types and with the novel ability to reason statically about the disjointness of types. The increased expressivity enables the analysis of important protocol classes that were previously out of scope for the type-based analyses of cryptographic protocols. In particular, our type systems can statically analyze protocols that are based on zero-knowledge proofs, even in scenarios when certain protocol participants are compromised. The analysis is scalable and provides security proofs for an unbounded number of protocol executions. The two type systems come with mechanized proofs of correctness and efficient implementations.
In FOCS 2001, Barak, Goldreich, Goldwasser and Lindell conjectured that the existence of ZAPs, introduced by Dwork and Naor in FOCS 2000, could lead to the design of a zeroknowledge proof system that is secure against both resetting provers and resetting verifiers. Their conjecture has been proven true by Deng, Goyal and Sahai in FOCS 2009 where both ZAPs and collision-resistant hash functions (CRHFs, for short) play a fundamental role. In this paper, we present a new technique that allows us to prove that simultaneously resettable zero knowledge can be achieved by relying on CRHFs only. Our construction therefore goes beyond the conjecture of Barak et al. bypassing the (demanding) use of ZAPs, that in turn require double enhanced trapdoor permutations (DTPs, for short). More specifically, we present the following results: 1. We construct the first resettably-sound resettable witness indistinguishable (rsrWI, for short) argument for NP based on CRHFs. Our construction exploits a new technique that we call “soundness upgrade”. In order to upgrade stand-alone soundness to resettable soundness, we use the lower bound proved by Rosen in CRYPTO 2000 on the round complexity of black-box concurrent zero knowledge. Moreover our rsrWI argument is an argument of knowledge (AoK, for short). 2. As an application of the above result, we obtain the main theorem of this work: we prove (constructively) the existence of an argument system that is both resettable zero knowledge and resettably sound under the sole assumption that CRHFs exist. Our results improve the state-of-the-art, and, perhaps even more importantly, provide a novel tool for the design of resettably-secure protocols. We also show a novel way to use protocol lower bounds in constructive protocol design.
Malicious insider security of authenticated key exchange (AKE) protocol addresses the situation that an AKE protocol is secure even with existing dishonest parties established by adversary in corresponding security experiment. In the eCK model, the EstablishParty query is used to model the malicious insider setting. However such strong query is not clearly formalized so far. We show that the proof of possession assumptions for registering public keys are of prime importance to malicious insider security. In contrast to previous schemes, we present an eCK secure protocol in the standard model, without assuming impractical, strong, concurrent zero-knowledge proofs of knowledge of secret keys done to the CA at key registration. The security proof of our scheme is based on standard pairing assumption, collision resistant hash functions, bilinear decision Diffie-Hellman (BDDH) and decision linear Diffie-Hellman (DLIN) assumptions, and pseudo-random functions with pairwise independent random source πPRF [14].
Sebastian Faust, Markulf Kohlweiss, Giorgia Azzurra Marson, Daniele Venturi
The Fiat-Shamir transform is a well studied paradigm for removing interaction from publiccoin protocols. We investigate whether the resulting non-interactive zero-knowledge (NIZK) proof systems also exhibit non-malleability properties that have up to now only been studied for NIZK proof systems in the common reference string model: first, we formally define simulation soundness and a weak form of simulation extraction in the random oracle model (ROM). Second, we show that in the ROM the Fiat-Shamir transform meets these properties under lenient conditions. A consequence of our result is that, in the ROM, we obtain truly efficient non malleable NIZK proof systems essentially for free. Our definitions are sufficient for instantiating the Naor-Yung paradigm for CCA2-secure encryption, as well as a generic construction for signature schemes from hard relations and simulation-extractable NIZK proof systems. These two constructions are interesting as the former preserves both the leakage resilience and key-dependent message security of the underlying CPA-secure encryption scheme, while the latter lifts the leakage resilience of the hard relation to the leakage resilience of the resulting signature scheme.
Abstract. We present the first wide-strong RFID identification protocol that is based on zero-knowledge. Until now this notion has only been achieved by schemes based on IND-CCA2 encryption. Rigorous proofs in the standard model are provided for the security and privacy properties of our protocol. Furthermore our protocol is the most efficient solution presented in the literature. Using only Elliptic Curve Cryptography (ECC), the required circuit area can be minimized such that our protocol even fits on small RFID tags. Concerning computation on the tag, we only require two scalar-EC point multiplications. Keywords. RFID, Private Identification, Zero-Knowledge, Elliptic Curve Cryptography. 1
The abstraction of cryptographic operations by term algebras, called symbolic models, is essential in almost all tool-supported methods for analyzing security protocols. Significant progress was made in proving that symbolic models offering basic cryptographic operations such as encryption and digital signatures can be sound with respect to actual crypto- graphic realizations and security definitions. Even abstractions of sophisticated modern cryptographic primitives such as zero- knowledge (ZK) proofs were shown to have a computationally sound cryptographic realization, but only in ad-hoc formalisms and at the cost of placing strong assumptions on the underlying cryptography, which leaves only highly inefficient realizations. In this paper, we make two contributions to this problem space. First, we identify weaker cryptographic assumptions that we show to be sufficient for computational soundness of symbolic ZK proofs. These weaker assumptions are fulfilled by existing efficient ZK schemes as well as generic ZK constructions. Second, we conduct all computational soundness proofs in CoSP, a recent framework that allows for casting com- putational soundness proofs in a modular manner, independent of the underlying symbolic calculi. Moreover, all computational soundness proofs conducted in CoSP automatically come with mechanized proof support through an embedding of the applied π-calculus. Keywords-Symbolic zero-knowledge proofs; computational soundness; weaker assumptions; mechanized proofs
Networks and entity groupings requires entity authentication while preserving the privacy of the entity being authenticated. Zero-Knowledge Proof (ZKP) plays an important role in authentication without revealing secret information. Diffie–Hellman (D-H) key exchange algorithm was developed to exchange secret keys through unprotected channels. This paper discusses zero-knowledge protocols and Diffie– Hellman algorithm and analyzes their vulnerability against known attacks. Also it presents a proposed protocol based on modification of Diffie–Hellman algorithm into an interactive zero-knowledge proof protocol. The proposed protocol is designed and developed to satisfy the zero-knowledge proof properties and resists the known attacks
Rosemberg Silva, Pierre-Louis Cayrel, Richard Lindner
In this paper we propose a new 5-pass zero-knowledge identification scheme with soundness error close to 1/2. We use the hardness of the Inhomogeneous Small Integer Solution problem as security basis. Our protocol achieves lower communication costs compared with previous lattice-based zeroknowledge identification schemes. Besides, our construction allows smaller public and secret keys by applying the use of ideal lattices. We allow the prover to possess several pairs of secret and public keys, and choose randomly which pair is to be used in a given round of execution. We also dealt with nonces in zero-knowledge schemes in a new way, lowering the number of values exchanged between the prover and the verifier. Hence, our scheme has the good features of having a zero-knowledge security proof based on a well known hard problem of lattice theory, with worst to average-case reduction, and small size of secret and public keys.
Experts predict that in the next 10 to 100 years scientists will succeed in creating human-level artificial general intelligence. While it is most likely that this task will be accomplished by a government agency or a large corporation, the possibility remains that it will be done by a single inventor or a small team of researchers. In this paper, we address the question of safeguarding a discovery which could without hesitation be said to be worth trillions of dollars. Specifically, we propose a method based on the combination of zero knowledge proofs and provably AI-complete CAPTCHA problems to show that a superintelligent system has been constructed without having to reveal the system itself.
Sławomir Grzonkowski, Peter Corcoran, Thomas Coughlin
A number of well-known authentication protocols are considered in the context of next-generation mobile and CE network services. The potential weaknesses of current protocols can be overcome using Zero Knowledge Proof (ZKP) techniques to protect user passwords so an alternative ZKP protocol, SeDiCi 2.0, is described. This offers mutual and also two-factor authentication that is considered more secure against various phishing attempts than existing trusted third party protocols. The suitability of such a ZKP protocol for various CE-based cloud computing applications is demonstrated.