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9,005 results ¡ page 356 of 376
Andrew Chi-Chih Yao, Frances Yao, Yunlei Zhao
No abstract is available for this record.
Divyesh Shah, Sheng Zhong
No abstract is available for this record.
Akihiro Yamamura, Kurokawa Takashi, Junji Nakazato
No abstract is available for this record.
Guilin Wang, Joonsang Baek, Duncan S. Wong, Feng Bao
No abstract is available for this record.
Yuval Ishai, Eyal Kushilevitz, Rafail Ostrovsky, Amit Sahai
We present a general construction of a zero-knowledge proof for an NP relation R(x,w) which only makes a black-box use of a secure protocol for a related multi-partyfunctionality f. The latter protocol is only required to be secure against a small number of "honest but curious" players. As an application, we can translate previous results on the efficiency of secure multiparty computation to the domain of zero-knowledge, improving over previous constructions of efficient zero-knowledge proofs. In particular, if verifying R on a witness of length m can be done by a circuit C of size s, and assuming one-way functions exist, we get the following types of zero-knowledge proof protocols.
Sae-Ran Kwon, Sangho Lee
No abstract is available for this record.
Iftach Haitner, Omer Reingold
Interactive hashing, introduced by Naor, Ostrovsky, Venkatesan, and Yung (J. Cryptol. 11(2):87â108, 1998 ), plays an important role in many cryptographic protocols. In particular, interactive hashing is a major component in all known constructions of statistically hiding commitment schemes and of statistical zero-knowledge arguments based on general one-way permutations/functions. Interactive hashing with respect to a one-way function f is a two-party protocol that enables a sender who knows y = f ( x ) to transfer a random hash z = h ( y ) to a receiver such that the sender is committed to y : the sender cannot come up with x and x Ⲡsuch that f ( x )â f ( x â˛), but h ( f ( x ))= h ( f ( x â˛))= z . Specifically, if f is a permutation and h is a two-to-one hash function, then the receiver does not learn which of the two preimages { y , y â˛}= h â1 ( z ) is the one the sender can invert with respect to f . This paper reexamines the notion of interactive hashing, and proves the security of a variant of the Naor et al. protocol, which yields a more versatile interactive hashing theorem. When applying our new proof to (an equivalent variant of) the Naor et al. protocol, we get an alternative proof for this protocol that seems simpler and more intuitive than the original one, and achieves better parameters (in terms of how security preserving the reduction is).
Hoeteck Wee
No abstract is available for this record.
Hirotada Kobayashi
This paper studies the complexity classes QZK and HVQZK of problems having a quantum computational zero-knowledge proof system and an honest-verifier quantum computational zero-knowledge proof system, respectively. The results proved in this paper include: (a) HVQZK = QZK, (b) any problem in QZK has a public-coin quantum computational zero-knowledge proof system, (c) any problem in QZK has a quantum computational zero-knowledge proof system of perfect completeness, and (d) any problem in QZK has a three-message public-coin quantum computational zero-knowledge proof system of perfect completeness with arbitrarily small constant error in soundness. All the results above are unconditional and do not rely any computational assumptions. For the classes QPZK, HVQPZK, and QSZK of problems having a quantum perfect zero-knowledge proof system, an honest-verifier quantum perfect zero-knowledge proof system, and a quantum statistical zero-knowledge proof system, respectively, the following new properties are proved: (e) HVQPZK = QPZK, (f) any problem in QPZK has a public-coin quantum perfect zero-knowledge proof system, (g) any problem in QSZK has a quantum statistical zero-knowledge proof system of perfect completeness, and (h) any problem in QSZK has a three-message public-coin quantum statistical zero-knowledge proof system of perfect completeness with arbitrarily small constant error in soundness. It is stressed that our proofs are direct and do not use complete promise problems or those equivalents. This gives a unified framework that works well for all of quantum perfect, statistical, and computational zero-knowledge proofs, and enables us to prove properties even on the computational and perfect zero-knowledge proofs for which no complete promise problems are known.
Kun Peng, Colin Boyd, Ed Dawson
The batch verification technique of Bellare et al. is extended to verification of several frequently employed zero-knowledge proofs. The new techniques are correct, sound, efficient, and can be widely applied. Specific applications are discussed in detail, including batch ZK proof and verification of validity of encryption (or reencryption) and batch ZK proof and verification of validity of decryption. Considerable efficiency improvements are gained in these two applications without compromising security. As a result, efficiency of the practical cryptographic systems (such as mix networks) based on these two applications is dramatically improved.
Bernard Chazelle
No abstract is available for this record.
Oded Goldreich, Silvio Micali, Avi Wigderson
No abstract is available for this record.
Gilles Brassard, Claude CrĂŠpeau
A zero-knowledge interactive proof is a protocol by which Alice can convince a polynomially-bounded Bob of the truth of some theorem without giving him any hint as to how the proof might proceed. Under cryptographic assumptions, we give a general technique for achieving this goal for every problem in NP. This extends to a presumably larger class, which combines the powers of non-determinism and randomness. Our protocol is powerful enough to allow Alice to convince Bob of theorems for which she does not even have a proof: it is enough for Alice to convince herself probabilistically of a theorem, perhaps thanks to her knowledge of some trap-door information, in order for her to be able to convince Bob as well, without compromising the trap-door in any way. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Juan RamĂłn Troncoso, Fernando PĂŠrezâGonzĂĄlez
Zero-knowledge watermark detectors presented to date are based on a linear correlation between the asset features and a given secret sequence. This detection function is susceptible of being attacked by sensitivity attacks, for which zero-knowledge does not provide protection. In this paper, an efficient zero-knowledge version of the Generalized Gaussian Maximum Likelihood (ML) detector is introduced. The inherent robustness that this detector presents against sensitivity attacks, together with the security provided by the zero-knowledge protocol that conceals the keys that could be used to remove the watermark or to produce forged assets, results in a robust and secure protocol. Two versions of the zero-knowledge detector are presented; the first one makes use of two new zero-knowledge proofs for modulus and square root calculation; the second is an improved version applicable when the spreading sequence is binary, and it has minimum communication complexity. Completeness, soundness and zero-knowledge properties of the developed protocols are proved, and they are compared with previous zero-knowledge watermark detection protocols in terms of receiver operating characteristic, resistance to sensitivity attacks and communication complexity.
Dario Catalano, Ivan Visconti
No abstract is available for this record.
Wei Han, Dong Zheng, Kefei Chen
Abstract: Cryptography is an important tool in the design and implementation of electronic voting schemes for it provides the property of verifiability, which is not provided in the traditional voting. But in the real life, neither can most voters understand the profound theory of cryptographic e-voting nor can they perform the complicated cryptographic computation. An e-voting system is presented in this paper to leverage the use of cryptography between theory and practice. It combines the advantages of Moran-Naorâs voting scheme and voting schemes based on homomorphic encryption. It makes use of cryptographic techniques, but it hides the details of cryptographic computation from voters. Voters can be convinced that the ballot is cast as intended. The tally can be verified in public. Compared with Moran-Naorâs voting scheme, the new system has three advantages: the ballots can be recovered when the voting machine breaks down, the costly cut-and-choose zero-knowledge proofs for shuffling votes made by the voting machine are avoided and the partial tally result in each voting machine is kept secret. Key words: electronic voting, homomorphic commitment, homomorphic encryption, threshold decryption 1.
Gerald V. Post
The current political climate has almost ruled out the use of Internet voting.Many politicians, led by vocal computer scientists, are pushing for voter verified paper receipts; which is likely to push us even further away from even electronic voting systems.On the other hand, cryptographers have created homomorphic encryption and non-interactive zero-knowledge proofs with features that can support Internet voting.Adding a few more protocols, including an extended voting period and repeat voting can solve the remaining problems need to make Internet voting at least as secure as existing systems.
Zhengjun Cao
Abstract Whether a recipient can prove a signature to others is of great importance. The function is just one reason that we call a signature âsignature â rather than others. In this paper, we point out that one popular signcryption signature convinces only the designated documentâs recipient that the signer deliberately signed the document. The designated recipient can check the validity of a given signcryptext but cannot prove it to others. We also improve it using the efficient technique developed in Schnorrâs signature instead of a zero-knowledge proof such that the receiver can check the validity of a given signcryptext and can prove it to a third party.
Liusheng Huang
A Publicly Verifiable Secret Sharing(PVSS) scheme is a verifiable secret sharing scheme with the property that the validity of the shares distributed by the dealer can be verified by any party,hence verification is not limited to the respective participants receiving the shares.So there are more application fields than a verifiable secret sharing.A non-interactive and information-theoretic PVSS scheme based on public cryptography and the zero-knowledge proof of knowledge were presented.It is very simple to implement,extend and renew this scheme,which especially fits the publicly verifiable secret sharing for general access structure.
Xiao-Yun Jia, Shou-Shan Luo, Ping Chen, Chaowei Yuan
A publicly verifiable encryption scheme allows any entity to verify whether a ciphertext hides the same message as committed but without revealing it. This paper presents an efficient publicly verifiable encryption scheme based on RSA and extends zero-knowledge proof of knowledge, which is not only suitable for one-recipient RSA encryption, but also can be applied to multi-recipient situation. It is more efficient than other encryption schemes.
Yael Tauman Kalai, Ran Raz
An interactive-PCP (say, for the membership x â L) is a proof that can be verified by reading only one of its bits, with the help of a very short interactive-proof. We show that for membership in some languages L, there are interactive-PCPs that are significantly shorter than the known (non-interactive) PCPs for these languages. Our main result is that the satisfiability of a constant depth Boolean formula ÎŚ(z1, . . . , zk) of size n (over the gates â§,â¨, â,ÂŹ) can be proved by an interactive-PCP of size poly(k), followed by a short interactive proof of communication complexity polylog(n). That is, we obtain interactivePCPs of size polynomial in the size of the witness. This compares to the known (non-interactive) PCPs that are of size polynomial in the size of the instance. By reductions, this result extends to many other central NP languages (e.g., SAT, k-clique, Vertex-Cover, etc.). More generally, we show that the satisfiability of Vn i=1[ÎŚi(z1, . . . , zk) = 0], where each ÎŚi(z1, . . . , zk) is an arithmetic formula of size n (say, over GF[2]) that computes a polynomial of degree d, can be proved by an interactive-PCP of size poly(k, d), followed by a short interactive proof of communication complexity poly(d, log n). We give many cryptographic applications and motivations for our results. In particular, we show the following: 1. The satisfiability of a constant depth formula ÎŚ(z1, . . . , zk) of size n (as above) has an interactive zero-knowledge proof of communication complexity poly(k) (rather than poly(n))1 . As before, this result extends to many other central NP languages. This zero-knowledge proof has some additional desired properties that will be elaborated on in the body of the paper. 2. Alice can commit to a Boolean formula Î of size m, by a message of size poly(m), and later on prove to Bob any N statements of the form Î(x1) = z1, . . . ,Î(xN ) = zN by a zero-knowledge proof of communication complexity poly(m, log N). Moreover, if Î is a constant depth Boolean formula then the zero-knowledge proof has communication complexity poly(log m, log N). We further motivate this application in the body of the paper.
Jiawei Dou, Shundong Li
Non-malleable commitment is recently one of research focuses in international cryptographic community. It has many important applications in e-commerce, and plays important role in constructing other cryptographic protocols. Most existing non-malleable commitment schemes are constructed by requiring that a committer proves, by zero-knowledge proof, that he knows his committed secret. The attached zero-knowledge proof process makes existing non-malleable commitments have higher computational and communication complexity. More efficient schemes are appealing. This paper constructs three new efficient non-malleable commitment schemes which do not require that a committer proves he knows his committed secret by zero-knowledge proof, but rather require a committer proves, by other arguments, that he does know the secret at the same time he makes commitment. These non-malleable commitment schemes, without zero-knowledge proof, are much more efficient.
Dai Jun
In this paper, we describe a new zero-knowledge proof procotol based on the discrete logarithm and higherorder non-linear variable coefficient differential transformation. By using the high order differential state sequence, the casuality of the system and the capability of resistance to identity deception and differential attacks is enhanced. By introduction of differential transformation method and input-output table into zero-knowledge proof protocol, a new research field for cryptography of zero-knowledge proof identity authentication is thus opened up.
Huafei Zhu, Ying Qiu, Feng Bao
Ad-hoc networks formed by peers without relying on any preexisting infrastructure, have been a very attractive field of academic and industrial research in recent years due to their potential applications. An ad-hoc network allows a peer node further to form a task-driven sub-network such that each node in the generated sub-network may exchange data with each other but any other non-member node is prohibited to access the subnetwork. As a result, a task-driven subnetwork generated by a peer node definitely requires membership proof mechanism (in the scenario of anonymous communications, anonymous membership proof systems are required). In this paper, we provide a novel mechanism for anonymous access control (anonymous membership proof systems) in ad- hoc networks based on a new notion which we call or-protocols in the common reference string model. An or-protocol in essence is a three move zero-knowledge proof system that allows a peer node to prove its membership of a given set which is publicly verifiable. Our protocol is of constant size, i.e., the length of a proof is independent with number of users in a given set, and thus is suitable for practice. Furthermore we show that our protocol is provably secure assuming that the discrete logarithm problem defined over prime field is hard.