Restrictive blinding of secret-key certificates

Many signature transporting mechanisms require a signer to issue triples, consisting of a secret key, a matching public key, and a certificate of the signer on the public key. Of particular interest are so-called restrictive blind signature issuing protocols, in which the receiver can blind the issued public key and the certificate but not a certain predicate of the secret key. This paper describes the first generally applicable technique for designing efficient such issuing protocols, based on the recently introduced notion of secret-key certificates. The resulting three-move issuing protocols require the receiver to perform merely a single on-line multiplication, and the property of restrictive blinding can be proved with respect to a plausible intractability assumption. Application of the new issuing protocols results in the most efficient and versatile off-line electronic cash systems known to date, without using the blind signature technique developed by Chaum

A note on parallel executions of restrictive blind issuing protocols for secret-key certificates

The receiver in a restrictive blind certificate issuing protocol can blind the issued public key and the certificate but not a certain blinding-invariant predicate of the secret key. Recently a generally applicable technique was described for designing restrictive blind issuing protocols for a certain type of secret-key certificates, and it was shown that the resulting issuing protocols should not be run in parallel since that would enable an attack in which completely blinded triples can be retrieved. To allow the signer in highly demanding applications to run the restrictive blind certificate issuing protocol in parallel mode, a simple technique for modifying the issuing protocols was proposed. In this note it is shown that the proposed modification technique does not overcome the parallel attack problem

Certificateless Blind Signature Based on DLP

The most widely used digital signature in the real word application such as e cash e-voting etc. is blind signature. Previously the proposed blind signature follow the foot steps of public key cryptography(PKC) but conventional public key cryptography uses an affirmation of a relationship between public key and identity for the holder of the corresponding private key to the user, so certificate management is very difficult. To overcome this problem Identity based cryptography is introduced. But Identity based cryptography is inherited with key escrow problem. Blind signature with certificateless PKC(CLBS) used widely because it eliminate the problem related to certificate management of cryptography and the key escrow problem of ID based PKC. Because of large requirement of CLBS scheme in different applications many CLBS scheme is proposed, but they were based on bilinear pairing. However, the CLBS scheme based on bilinear pairing is not very satisfiable because bilinear pairing operations are very complicated. In our proposed scheme, we designed a certificateless blind signature scheme based on the discrete logarithmic problem. The proposed scheme fulfills all the security requirements of blind signature as well as certificateless signature. We analyzed security properties such as blindness, unforgeability and unlinkability. The proposed scheme has less computational cost. The hardness of discrete logarithmic problem (DLP) is used to prove the security of the proposed scheme

A Novel Identity Based Blind Signature Scheme using DLP for E-Commerce

Abstract— Blind signatures are used in the most of the application where confidentiality and authenticity are the main issue. Blind signature scheme deals with concept where requester sends the request that the signer should sign on a blind message without looking at the content. Many ID based blind signature are proposed using bilinear pairings and elliptic curve. But the relative computation cost of the pairing in bilinear pairings and ID map into an elliptic curve are huge. In order to save the running time and the size of the signature, this paper proposed a scheme having the property of both concepts identity based blind signature that is based on Discrete Logarithm Problem, so as we know that DLP is a computational hard problem and hence the proposed scheme achieves all essential and secondary security prematurity. With the help of the proposed scheme, this paper implemented an E-commerce system in a secure way. E-commerce is one of the most concern applications of ID based blind signature scheme. E-commerce consisting selling and buying of products or services over the internet and open network. ID based blind signature scheme basically has been used enormously as a part of today’s focussed business. Our proposed scheme can be also be used in E-business, E-voting and E-cashing anywhere without any restriction DOI: 10.17762/ijritcc2321-8169.15060

Security and Privacy Issues in Wireless Mesh Networks: A Survey

This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio

Proceedings of the 2nd International Workshop on Security in Mobile Multiagent Systems

This report contains the Proceedings of the Second Workshop on Security on Security of Mobile Multiagent Systems (SEMAS2002). The Workshop was held in Montreal, Canada as a satellite event to the 5th International Conference on Autonomous Agents in 2001. The far reaching influence of the Internet has resulted in an increased interest in agent technologies, which are poised to play a key role in the implementation of successful Internet and WWW-based applications in the future. While there is still considerable hype concerning agent technologies, there is also an increasing awareness of the problems involved. In particular, that these applications will not be successful unless security issues can be adequately handled. Although there is a large body of work on cryptographic techniques that provide basic building-blocks to solve specific security problems, relatively little work has been done in investigating security in the multiagent system context. Related problems are secure communication between agents, implementation of trust models/authentication procedures or even reflections of agents on security mechanisms. The introduction of mobile software agents significantly increases the risks involved in Internet and WWW-based applications. For example, if we allow agents to enter our hosts or private networks, we must offer the agents a platform so that they can execute correctly but at the same time ensure that they will not have deleterious effects on our hosts or any other agents / processes in our network. If we send out mobile agents, we should also be able to provide guarantees about specific aspects of their behaviour, i.e., we are not only interested in whether the agents carry out-out their intended task correctly. They must defend themselves against attacks initiated by other agents, and survive in potentially malicious environments. Agent technologies can also be used to support network security. For example in the context of intrusion detection, intelligent guardian agents may be used to analyse the behaviour of agents on a firewall or intelligent monitoring agents can be used to analyse the behaviour of agents migrating through a network. Part of the inspiration for such multi-agent systems comes from primitive animal behaviour, such as that of guardian ants protecting their hill or from biological immune systems

Privacy considerations for secure identification in social wireless networks

This thesis focuses on privacy aspects of identification and key exchange schemes for mobile social networks. In particular, we consider identification schemes that combine wide area mobile communication with short range communication such as Bluetooth, WiFi. The goal of the thesis is to identify possible security threats to personal information of users and to define a framework of security and privacy requirements in the context of mobile social networking. The main focus of the work is on security in closed groups and the procedures of secure registration, identification and invitation of users in mobile social networks. The thesis includes an evaluation of the proposed identification and key exchange schemes and a proposal for a series of modifications that augments its privacy-preserving capabilities. The ultimate design provides secure and effective identity management in the context of, and in respect to, the protection of user identity privacy in mobile social networks