Blockchain Papers

Bogdan Cărbunar, Radu Sion

No abstract is available for this record.

Kazi Md. Rokibul Alam, Shinsuke Tamura, Shuji Taniguchi, Tatsuro Yanase

This paper proposes a new electronic voting (e-voting) scheme that fulfills all the security requirements of e-voting i.e. privacy, accuracy, universal verifiability, fairness, receipt-freeness, incoercibility, dispute-freeness, robustness, practicality and scalability; usually some of which are found to be traded. When compared with other existing schemes, this scheme requires much more simple computations and weaker assumptions about trustworthiness of individual election authorities. The key mechanism is the one that uses confirmation numbers involved in individual votes to make votes verifiable while disabling all entities including voters themselves to know the linkages between voters and their votes. Many existing e-voting schemes extensively deploy zero-knowledge proof (ZKP) to achieve verifiability. However, ZKP is expensive and complicated. The confirmation numbers attain the verifiability requirement in a much more simple and intuitive way, then the scheme becomes scalable and practical.

Michael Backes, Stefan Lorenz, Matteo Maffei, Kim Pecina

No abstract is available for this record.

Ryan Henry, Kevin Henry, Ian Goldberg

No abstract is available for this record.

Ivan Damgård, Yuval Ishai, Mikkel Krøigaard

No abstract is available for this record.

Yang Yang, Ya-tao, Cao, LüLin · 6 authors

In order to solve the issue that existing direct anonymous attestation (DAA) scheme can not operate effectively in different domains,based on the original DAA scheme,a novel direct anonymous attestation protocol used in multi domains environment is proposed and designed,in which,the certificate issuer located in outside of domain can be considered as a proxy server to issue the DAA certificate for valid member nodes directly.Our designed mechanism accords with present trusted computing group (TCG) international specification,and can solve the problems of practical authentication and privacy information protection between different trusted domains efficiently.Compared with present DAA scheme,in our protocol,the anonymity,unforgeability can be guaranteed,and the replay-attack also can be avoided.It has important referenced and practical application value in trusted computing field.

Sławomir Grzonkowski

No abstract is available for this record.

Francesc Sebé, Josep M. Miret, Jordi Pujolàs, Jordi Puiggalı́

No abstract is available for this record.

Kazi Md. Rokibul Alam, Shinsuke Tamura

This paper proposes a new electronic voting (e-voting) scheme that fulfills all the security requirements of e-voting. The key mechanism is the one that uses confirmation numbers involved in individual votes to make votes verifiable while disabling all entities including voters themselves to know the linkages between voters and their votes. Unlike complicated zero knowledge proof involved in many e-voting schemes, the confirmation numbers attain the verifiability requirement in a much more simple and intuitive way, then the scheme becomes scalable and practical.

Tian Zhou, Li Li

A secure web-based watermarking scheme is proposed to allow the publisher or information provider to mark their copyrighted materials and identify an illegal distributor through the World Wide Web (WWW). In our proposed scheme, multi-watermark techniques and double encryption method is applied to make the scheme available in e-transaction and secure against collusion attacks even if the third party is not trusted. And the basic idea of zero knowledge proof is also used to make verification of an illegal distributor without the disclosure of any watermark information. Furthermore, a multiparty transaction scenario is also introduced by using our scheme in this paper. The analysis results indicate that our design goals are successfully achieved and some improvements are made over previously proposed schemes.

Xie Kang-le

The anonymous authentication schemes for Trusted Computing Platform(TCP) is studied in this paper, the advantages and disadvantages of the subsistent authentication schemes for TCP are analyzed. A new anonymous authentication scheme for TCP is proposed by using the method of zero-knowledge proof. The validity of a TPM platform is proved anonymously, and there is no trusted third party to participate in the authentication schemes. The new scheme has higher efficiency than others and satisfies forgery-resistance, anonymity and revocation under strong RSA assumption and Diffie-Hellman assumption in the random model.

Shlomi Dolev, Marina Kopeetsky

No abstract is available for this record.

Jian Wang

This paper first gives out definition of receipt-freeness,and prove necessary and sufficient condition of receipt-freeness. Then by employing homomorphic ElGamal encryption,threshold ElGamal encryption and zero-knowledge proof,this paper designs an efficient electronic voting scheme,which satisfies universal verifiability,receipt-freeness,also eligibility,privacy and so on. Different from the previous protocols,there needs less security requirement on trusted third party in the new scheme,which is more practical.

Matt Smart, Eike Ritter

No abstract is available for this record.

Man Ho Au

Digital signatures are fundamental cryptographic primitives. They are useful as a stand-alone application and building blocks of complex cryptographic systems. Accumulators are another useful cryptographic primitive which provide a way to combine a set of values into one short value. They are useful in improving efficiency of cryptographic systems. In particular, these two primitives are key components in privacy-preserving cryptographic systems. In this thesis, we study the use of digital signatures and accumulators in cryptographic applications. We design digital signature schemes and accumulators with different features that are suitable for a wide range of applications. We are interested in privacy-preserving cryptographic applications including anonymous electronic cash systems, anonymous authentication schemes and anonymous credential systems. We construct three different digital signature schemes, each with distinctive features. We also propose two novel constructions of accumulators. Based on our signature schemes and accumulators, we design two compact electronic cash schemes and a divisible electronic cash scheme. All our schemes are truly anonymous, meaning that privacy of the users is well-protected. We also explore other applications of our newly proposed signatures and accumulators. Specifically, we give a construction of k-times anonymous authentication schemes and attribute-based anonymous credential systems. During the course of the development of the thesis, we generalise existing techniques of zero-knowledge proof-of-knowledge protocol of double-discrete logarithms into zero-knowledge proof-of-knowledge protocol of representation of a committed value. Our protocol is compatible with existing zero-knowledge proof-of-knowledge protocols that demonstrate relationship amongst discrete logarithms. We believe that this protocol, together with the newly introduced primitives, are of independent interest.

Sebastiaan de Hoogh, Berry Schoenmakers, Boris Škorić, José Villegas

No abstract is available for this record.

Iftach Haitner, Alon Rosen, Ronen Shaltiel

No abstract is available for this record.

Ying Qiu, Huafei Zhu

This paper studies mobile devices mediated electronic voting system based on the distributed Pailler's encryptions; We apply the standard cut-of-the-choose technique to avoid the computational zero-knowledge proofs and show that the proposed scheme is efficient yet somewhat provably secure in the simulation-based paradigm.

Junhua Chen, Peng Wu

Combining the identification characteristics of zero-knowledge proof and blind watermark, an identity verification protocol is proposed. In this protocol, the public key encryption is used to encrypt the watermark and the watermarked data of the watermark embedding locations, and the verification of user's identity watermarking is achieved through estimating the relativity of them. Furthermore, a way which restricts the prover and verifierpsilas communication to a closed situation is put forward, and this way can resist such as brute force cheat-attack.

Jacek Cichoń, Marek Klonowski, Mirosław Kutyłowski

No abstract is available for this record.

Peter Y. A. Ryan

No abstract is available for this record.

Jens Groth, Yuval Ishai

No abstract is available for this record.

Liu Quan, Zheng Chen, Zhou Zude

A new buyer-seller watermarking protocol is proposed by applying a double encryption method and a novel mechanism of embedding a buyer's watermark. The protocol can effectively prevent against collusion attacks and the man in the middle attack if the third party is not trusted. Also, based on the proposed scheme for the first-hand transaction, a new buyer-reseller watermarking protocol and a formal multi-party watermarking protocol are also proposed. The proposed buyer-resell watermarking protocol only needs the original seller to provide transfer certificate and encryption-decryption service to support the second-hand transaction, and the multi-party watermarking protocol with distributed certificate authorities can overcome the difficulty in the combination of multicast mechanism with multiple unique watermarks and allow a seller to multicast the watermarked digital contents and key transaction information to n buyers. Furthermore, the idea of zero knowledge proof is also applied into the proposed scheme to allow the seller to take an effective control on the task performed by the third party.

Wei Han, Hao Tao, Dong Zheng, Kefei Chen · 5 authors

To provide a high level of security guarantee cryptography is introduced into the design of the voting machine. The voting machine based on cryptography is vulnerable to attacks through covert channels. An adversary may inject malicious codes into the voting machine and make it leak vote information unnoticeably by exploiting the randomness used in encryptions and zero-knowledge proofs. In this paper a voting machine resistant to covert channels is designed. It has the following properties: Firstly, it is tamper-evident. The randomness used by the voting machine is generated by the election authority. The inconsistent use of the randomness can be detected by the voter from examining a destroyable verification code. Even if malicious codes are run in the voting machine attacks through subliminal channels are thwarted. Next, it is voter-verifiable. The voter has the ability to verify if the ballot cast by the machine is consistent with her intent without doing complicated cryptographic computation. Finally, the voting system is receipt-free. Vote-buying and coercion are prevented.