Sonu Mariam Paulose, R. Venkatesan, K. Ramalakshmi
Conjunction of massive amount of idle computers or resources that may be loosely coupled, heterogeneous and geographically dispersed to reach a common goal leads to a virtual computing platform for sharing resources across the world. Resource management, application development and usage models in these environments has some dilemma in undertaking resources due to resource providers with multiple administrative domains having their own policies and terms. A ditch in the Grid computing environment is how to coordinate the distributed resources amongst a dynamic set of individuals and organizations where the requesters and providers are allowed to join and leave Grid environment at any time. Bidding model prevents single point of failure and server overload problems of match making model while minimizing turnaround time by using some set of deterministic and probabilistic selection heuristics where resource requesters and resource providers were given the privilege to take autonomous decisions regarding resource selection. Autonomous decision making is enabled via peer-to-peer decentralized scheduling frame work. In decentralized environment, lack of global information is a key challenge to facilitate optimum decision making which can lead to greedy selection of the best provider. Therefore some probabilistic selection is used to reduce the fairness deviation among processors while minimizing the turnaround time. Currently just various level of information about providers has been concentrated to minimize the turnaround time. Simply concentrating on various level of information may also leads to failure due to rejection factor resulted by number of failures occurred at provider. However by merging trust oriented mechanisms along with various level of information, rejection factor can also be minimized along with minimization of the turnaround time.
Harry Kalodner, Miles Carlsten, Paul Ellenbogen, Joseph Bonneau · 5 authors
Secure decentralized namespaces have recently become possible due to cryptocurrency technology. They enable a censorship-resistant domainname system outside the control of any single entity, among other applications. Namecoin, a fork of Bitcoin, is the most prominent example. We initiate the study of decentralized namespaces and the market for names in such systems. Our extensive empirical analysis of Namecoin reveals a system in disrepair. Indeed, our methodology for detecting “squatted” and otherwise inactive domains reveals that among Namecoin’s roughly 120,000 registered domain names, a mere 28 are not squatted and have nontrivial content. Further, we develop techniques for detecting transfers of domains in the Namecoin block chain and provide evidence that the market for domains is thin-tononexistent. We argue that the state of the art in mechanism design for decentralized namespace markets is lacking. We propose a model of utility of different names to different participants, and articulate desiderata of a decentralized namespace in terms of this utility function. We use this model to explore the design space of mechanisms and analyze the trade-offs.
Abstract. In resetting attacks against a proof system, a prover or a verifier is reset and enforced to use the same random tape on various inputs as many times as an adversary may want. Recent deployment of cloud computing gives these attacks a new importance. This paper shows that argument systems for any NP language that are both resettably-sound and resettable zero-knowledge are possible by a constant-round protocol in the BPK model. For that sake, we define and construct a resettablyextractable conditional commitment scheme.
In the standard definition of a commitment scheme, the sender commits to a message and immediately sends the commitment to the recipient interested in it. However the sender may not always know at the time of commitment who will become interested in it. Further, when the interested party does emerge, it could be critical to establish when the commitment was made. Employing a proof of work protocol at commitment time will later allow anyone to carbon date when the commitment was made, approximately, without trusting any external parties. We present CommitCoin, an instantiation of this approach that harnesses the existing computational power of the Bitcoin peer-to-peer network; a network used to mint and trade digital cash.
We present a method to compile Yao’s two-player garbled circuit protocol into one that is secure against malicious adversaries that relies on witness indistinguishability. Our approach can enjoy lower communication and computation overhead than methods based on cut-andchoose [13] and lower overhead than methods based on zero-knowledge proofs [8] (or Σ-protocols [14]). To do so, we develop and analyze new solutions to issues arising with this transformation: — How to guarantee the generator’s input consistency — How to support different outputs for each player without adding extra gates to the circuit of the function f being computed — How the evaluator can retrieve input keys but avoid selective failure attacks — Challenging 3/5 of the circuits is near optimal for cut-and-choose (and better than challenging 1/2) Our protocols require the existence of secure-OT and claw-free functions that have a weak malleability property. We discuss an experimental implementation of our protocol to validate our efficiency claims.
ICT-lawyer (partner) at time.lex, a Brussels based law firm with focus on business law in the information society. His areas of interest are legal management of ICT-projects, data protection and privacy, e-business, electronic contracting, outsourcing and service level agreements, intellectual property, security, electronic invoicing, copyright, trade marks, e-money, e-banking and payments etc. He is also an associate researcher at the Interdisciplinary Centre for Law and Information Technology (ICRI) at the University of Leuven, and assistant at the University of Antwerp. Bitcoin is a free open source peer-to-peer electronic cash system that is completely decentralised, without the need for a central server or trusted parties. This article focuses briefly on some legal issues related to financial regulatory aspects about e-money and payment services.
Abstract. In the standard definition of a commitment scheme, the sender commits to a message and immediately sends the commitment to the recipient interested in it. However the sender may not always know at the time of commitment who will become interested in verifying it. Further, when the interested party does emerge, it could be critical to establish when the commitment was made. Employing a proof of work protocol at commitment time will later allow anyone to “carbon date ” when the commitment was made, approximately, without trusting any external parties. We present CommitCoin, an instantiation of this approach that harnesses the existing processing power of the Bitcoin peer-to-peer network; a network used to mint and trade digital cash. 1 Introductory Remarks Consider the scenario where Alice makes an important discovery. It is important to her that she receives recognition for her breakthrough, however she would also like to keep it a secret until she can establish a suitable infrastructure for monetizing it. By forgoing publication of her discovery, she risks Bob independently making the same discovery and publicizing it as his own. Folklore suggests that Alice might mail herself a copy of her discovery and leave the letter sealed, with the postal service’s timestamp intact, for a later resolution time. If Bob later claims the same discovery, the
Traditional electricity meters are replaced by Smart Meters in customers' households. Smart Meters collects fine-grained utility consumption profiles from customers, which in turn enables the introduction of dynamic, time-of-use tariffs. However, the fine-grained usage data that is compiled in this process also allows to infer the inhabitant's personal schedules and habits. We propose a privacy-preserving protocol that enables billing with time-of-use tariffs without disclosing the actual consumption profile to the supplier. Our approach relies on a zero-knowledge proof based on Pedersen Commitments performed by a plug-in privacy component that is put into the communication link between Smart Meter and supplier's back-end system. We require no changes to the Smart Meter hardware and only small changes to the software of Smart Meter and back-end system. In this paper we describe the functional and privacy requirements, the specification and security proof of our solution and give a performance evaluation of a prototypical implementation.
Cloud computing provides a novel computing paradigm for enterprises to store programs and data in the Cloud in a transparent manner, which poses the challenge of security and privacy. In this paper, based on homomorphic cryptography and Zero-Knowledge Proof, we present a novel privacy-preserving scheme for Cloud publish/subscribe service, which achieve efficient privacy-preserving authentication, data integrity, and publish-subscribe confidentiality. The performance evaluation and security analysis demonstrate the practice and validity of the proposed scheme.
Based on the interactive proof of Hamiltonian Cycle (HC) of large directed graph, which is a $\Sigma$-protocol, we construct a perfectly hiding and computationally binding trapdoor commitment in 2-round from any one-way permutation. Then, based on this trapdoor commitment, we construct perfect zero-knowledge argument of knowledge with negligible error probability in 2-round for $\mathcal{NP}$, assuming only the existence of a one-way permutation.
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.
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.
As its own security risks of existing patent trading platform, on-line patent transaction can not be realized. The security problems are mainly embodied in the confidentiality of transaction information, and security of patent delivery areas. One of the important characteristics of zero-knowledge proof is zero-knowledge, which can enable the verifier to believe that the conclusion is correct without knowing the contents of it. This characteristic can solve the problems of current patent transaction security mentioned above. Based on zero-knowledge proof, through the framework and flow design, this paper builds a secure patent trading platform, which shows a new way of patent trading. What is more, the security and convenience of this trading platform are better than ever before.
The use of information system has spread rapidly along with the increasing need for well-integrated information. PKPU as one of social foundations in Surabaya gives facility in fundraising given by the donors and then distributes them to the poor, such as tsunami victims, flood victims, etc. Now, PKPU is still using excel to do their financial reports. The researcher found many weaknesses in using excel to do these. It needs a long time to find the donors’ data. PKPU does not produce profit and loss report, instead PKPU produces balance report. To solve the problems above, there should be a system that can help fundraiser and the person in the accounting department in making financial report. Based on the testing, the researcher concludes that information system for social funding general ledger supported by sms facility is the solution to the problems dealing with computerized financial report. This is because this system can create financial report automatically. For example, it can be used to make journal report, ledger report, etc. In addition, since this system is suppported by SMS facility, this system can give easier information to the donors. Kata Kunci: information system, ledger, accounting, sms
At the heart of many fair exchange problems is verifiable escrow: a sender encrypts some value using the public key of a trusted party (called the recovery agent), and then must convince the receiver of the ciphertext that the corresponding plaintext satisfies some property (e.g., it contains the sender’s signature on a contract). Previous solutions to this problem are interactive, and often rely on communication-intensive cut-and-choose zero-knowledge proofs. In this paper, we provide a solution that uses generic trusted hardware to create an efficient, non-interactive verifiable escrow scheme. Our solution allows the protocol to use a set of recovery agents with a threshold access structure, the verifiable group escrow notion which was informally introduced by Camenisch and Damgard and which is formalized here. Finally, this paper shows how this new non-interactive verifiable escrow scheme can be used to create an efficient optimistic protocol for fair exchange of signatures.
A publicly verifiable multi-secret sharing scheme is proposed, using non-interactive zero-knowledge proof protocol and Shamir’s sharing system. The security of the scheme is based on the intractability of integer factorization problem and discrete logarithm problem. The validity of the sharing distributed by the dealer can be verified by anyone. Recovering the secret, participants only need to provide a shadow of the sharing. It is difficult to get the sharing from the shadow. So the sharing can be reused to share the multi-secret. Moreover, the validity of the shadow can also be verified by anyone. So the scheme is secure, efficient, and can prevent both dealer and participant from cheating.