Aiming at the problem that current schemes can not protect the benefits of proxy signer and message owner at the same time,this paper presents a blind proxy blind signature scheme on elliptic curve. By using Elliptic Curve Cryptography(ECC) and zero-knowledge proof,it has small amount of computing,high security and high implementation efficiency. Security analysis proves that the scheme satisfies the security properties of blind proxy signature scheme and proxy blind signature scheme,and it has strong enforceability.
Markus Rückert, Michael Schneider, Dominique Schröder
Verifiably encrypted signature schemes (VES) allow a signer to encrypt his or her signature under the public key of a trusted third party, while maintaining public signature verifiability. With our work, we propose two generic constructions based on Merkle authentication trees that do not require non-interactive zero-knowledge proofs (NIZKs) for maintaining verifiability. Both are stateful and secure in the standard model. Furthermore, we extend the specification for VES, bringing it closer to real-world needs. We also argue that statefulness can be a feature in common business scenarios.
Our constructions rely on the assumption that CPA (even slightly weaker) secure encryption, maskable CMA secure signatures, and collision resistant hash functions exist. Maskable means that a signature can be hidden in a verifiable way using a secret masking value. Unmasking the signature is hard without knowing the secret masking value. We show that our constructions can be instantiated with a broad range of efficient signature and encryption schemes, including two lattice-based primitives. Thus, VES schemes can be based on the hardness of worstcase lattice problems, making them secure against subexponential and quantum-computer attacks. Among others, we provide the first efficient pairing-free instantiation in the standard model.
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.
This paper presents a property attestation protocol for the security chip TCM (trusted cryptographic module) via analyzing the problems of the current property attestation, which is built on the property attestation model with the online trust third party. In the protocol the prover utilizes the zero-knowledge proof by the attribute certificates, configuration commitment and TCM signature, and attests its configuration and status which are compliant with the declarative security property. The protocol is characterized by shorter signature length and lower computations. The security of the protocol is proved at the random oracle model. The protocol can help extend application and improve standard for security chip TCM, and it also has practical value and immediate significance.
Abstract- This paper introduces a new intractable security problem whose intractability is due to the NP completeness of multivariate quadratic problem. This novel problem uses quaternion algebra in conjunction with MQ. Starting with the simultaneous multivariate equations, we transform these equations into simultaneous quaternion based multivariate quadratic equations. A new scheme for computational zero knowledge proof based on this problem is proposed. It is proved that according to black box definition of zero knowledge proof (ZKP) system, the proposed scheme is ZKP. Our proof has two lemmas. The proof is done through two lemmas. In the first lemma it is shown that expected polynomial time machine *VM halts in a polynomial time. In the second lemma, it is showed that the probability ensembles
Abstract. The concept of zero-knowledge proofs has been around for about 25 years. It has been redefined over and over to suit the special security requirements of protocols and systems. Common among all definitions is the requirement of the existence of some efficient “device ” simulating the view of the verifier (or the transcript of the protocol), such that the simulation is indistinguishable from the reality. The definitions differ in many respects, including the type and power of the devices, the order of quantifiers, the type of indistinguishability, and so on. In this paper, we will scrutinize the definition of “black-box computational ” zero-knowledge, in which there exists one simulator for all verifiers, the simulator has black-box access to the verifier, and the quality of simulation is such that the real and simulated views cannot be distinguished by polynomial tests (computational indistinguisha-bility). Working in a theoretical model (the Random-Oracle Model), we show that the indistinguishability requirement is stated in a conceptually inappropriate way: Present definitions allow the knowledge of the verifier and distin-guisher to be independent, while the two entities are essentially coupled. Therefore, our main take on the problem will be conceptual and semantic, rather than literal. We formalize the concept by introducing a “knowledge ex-tractor ” into the model, which tries to extract the extra knowledge hard-coded into the distinguisher (if any), and then helps the simulator to construct the view of the verifier. The new paradigm is termed Simulation-Extraction
This paper presents a new zero-knowledge protocol for SDH pair,which based on TOO/BB-E encryption from DBDH as-sumption.This protocal's security is stronger than reference[1].
Ali Bagherzandi, Stanisław Jarecki, Nitesh Saxena, Yanbin Lu
We revisit the problem of protecting user’s private data against adversarial compromise of user’s device(s) which would normally store this data. We formalize an attractive solution to this problem as PasswordProtected Secret-Sharing (PPSS), which is a protocol that allows a user to secret-share her data among n trustees in such a way that (1) the user can retrieve the shared secret upon entering a correct password into a reconstruction protocol which succeeds as long as at least t+ 1 honest trustees participate, and (2) the shared data remains secret even against the adversary which corrupts at most t servers, with the level of protection expected of passwordauthentication, i.e. the probability that the adversary learns anything useful about the secret is at most negligibly greater than q/|D| where q is the number of reconstruction protocol instances in which adversary engages and |D| is the size of the dictionary from which the password was randomly chosen. We propose an efficient PPSS protocol in the public key model, i.e. where the device can remember a trusted public key, provably secure under the DDH assumption, using non-interactive zero-knowledge proofs which are efficiently instantiatable in the Random Oracle Model (ROM). The resulting protocol is robust and practical, with fewer than 4t + 12 exponentiations per party, and with only three messages exchanged between the user and each server, implying a single round of interaction in the on-line phase. As a side benefit our PPSS protocol yields a new Threshold Password Authenticated Key Exchange (T-PAKE) protocol in the public key model which is significantly faster than existing T-PAKE’s provably secure in the public key model in ROM.
Multiparty computation protocols have been known for more than twenty years now, but due to their lack of efficiency their use is still limited in real-world applications: the goal of this paper is the design of efficient two and multi party computation protocols aimed to fill the gap between theory and practice. We propose a new protocol to securely evaluate reactive arithmetic circuits, that offers security against an active adversary in the universally composable security framework. Instead of the “do-and-compile” approach (where the parties use zero-knowledge proofs to show that they are following the protocol) our key ingredient is an efficient version of the “cut-and-choose” technique, that allow us to achieve active security for just a (small) constant amount of work more than for passive security.