A Revocable Online-Offline Certificateless Signature Scheme without Pairing

Certificateless Public key Cryptography is a widely studied paradigm due to its advantages of not having the key-escrow problem and the lack of use of certificates. Online-Offline signature schemes are extremely relevant today because of their great practical applications. In an online-offline signature scheme all the heavy computation is done on powerful processors and stored securely in the offline phase, and the online component requires only light computation. Hence, it is widely used in several low-resource devices like mobile phones, etc. Revocation is another important problem of wide interest as it helps to keep a check on misbehaving users. Currently, there are very few revocable certificateless signature schemes in the literature. We have addressed some of the limitations of the previously existing schemes and designed a new model for the same that involves periodic time generated keys. We present a revocable online-offline certificateless signature scheme without pairing. Pairing, though a very useful mathematical function, comes at the cost of heavy computation. Our scheme is proved secure in the random oracle model using a tight security reduction to the computational Diffie-Hellman problem

Cryptanalysis of a certificateless aggregate signature scheme

Recently, Nie et al. proposed a certificateless aggregate signature scheme. In the standard security model considered in certificateless cryptography, we are dealing with two types of adversaries. In this paper, we show that Nie et al.\u27s scheme is insecure against the adversary of the first type. In other words, although they claimed that their proposed scheme is existentially unforgeable against adaptive chosen message attack considering the adversaries in certificateless settings, we prove that such a forgery can be done

A Certificate-Based Proxy Signature with Message Recovery without Bilinear Pairing

In this paper, we propose the first provable secure certificate-based proxy signature with message recovery without bilinear pairing. The notion of certificate-based cryptography was initially introduced by Gentry in 2003, in order to simplify certificate management in traditional public key cryptography(PKC)and to solve the key escrow problem in identity-based cryptosystems. To date, a number of certificate-based proxy signature(CBPS)schemes from bilinear pairing have been proposed. Nonetheless, the total computation cost of a pairing is higher than that of scalar multiplication(e.g., over elliptic curve group). Consequently, schemes without pairings would be more appealing in terms of efficiency. According to the available research in this regard, our scheme is the first provable secure CBPS scheme with message recovery which is based on the elliptic curve discrete logarithm problem. We prove the security of the presented scheme against existential forgery under adaptive chosen message and ID attacks in the random oracle model. Moreover, the paper will also show how it would be possible to convert this scheme to the CBPS scheme without message recovery. This scheme has more applications in situations with limited bandwidth and power-constrained devices

A COMPREHENSIVE STUDY OF CRYPTOGRAPHY AND KEY MANAGEMENT BASED SECURITY IN CLOUD COMPUTING

Cloud computing is a cost effective flexible and proven delivery platform for providing consumer IT services or business services over internet. It has an ability to provide many services over internet. It not only provides computing services but additional computing resources. To interact with various services in the cloud and to store retrieve data from cloud several security mechanism is required. Cryptography and key management mechanism are one of the import services in the cloud to secure data. In this context, this paper investigates the basic problem of cloud computing with cryptography and key management system for enabling support of interoperability between cloud cryptography client and key management services

Certificateless Algorithm for Body Sensor Network and Remote Medical Server Units Authentication over Public Wireless Channels

Wireless sensor networks process and exchange mission-critical data relating to patients’ health status. Obviously, any leakages of the sensed data can have serious consequences which can endanger the lives of patients. As such, there is need for strong security and privacy protection of the data in storage as well as the data in transit. Over the recent past, researchers have developed numerous security protocols based on digital signatures, advanced encryption standard, digital certificates and elliptic curve cryptography among other approaches. However, previous studies have shown the existence of many security and privacy gaps that can be exploited by attackers to cause some harm in these networks. In addition, some techniques such as digital certificates have high storage and computation complexities occasioned by certificate and public key management issues. In this paper, a certificateless algorithm is developed for authenticating the body sensors and remote medical server units. Security analysis has shown that it offers data privacy, secure session key agreement, untraceability and anonymity. It can also withstand typical wireless sensor networks attacks such as impersonation, packet replay and man-in-the-middle. On the other hand, it is demonstrated to have the least execution time and bandwidth requirements

Secure and privacy-aware proxy mobile IPv6 protocol for vehicle-to-grid networks

Vehicle-to-Grid (V2G) networks have emerged as a new communication paradigm between Electric Vehicles (EVs) and the Smart Grid (SG). In order to ensure seamless communications between mobile EVs and the electric vehicle supply equipment, the support of ubiquitous and transparent mobile IP communications is essential in V2G networks. However, enabling mobile IP communications raises real concerns about the possibility of tracking the locations of connected EVs through their mobile IP addresses. In this paper, we employ certificate-less public key cryptography in synergy with the restrictive partially blind signature technique to construct a secure and privacy-aware proxy mobile IPv6 (SP-PMIPv6) protocol for V2G networks. SP-PMIPv6 achieves low authentication latency while protecting the identity and location privacy of the mobile EV. We evaluate the SP-PMIPv6 protocol in terms of its authentication overhead and the information-theoretic uncertainty derived by the mutual information metric to show the high level of achieved anonymity

A survey on wireless body area networks: architecture, security challenges and research opportunities.

In the era of communication technologies, wireless healthcare networks enable innovative applications to enhance the quality of patients’ lives, provide useful monitoring tools for caregivers, and allows timely intervention. However, due to the sensitive information within the Wireless Body Area Networks (WBANs), insecure data violates the patients’ privacy and may consequently lead to improper medical diagnosis and/or treatment. Achieving a high level of security and privacy in WBAN involves various challenges due to its resource limitations and critical applications. In this paper, a comprehensive survey of the WBAN technology is provided, with a particular focus on the security and privacy concerns along with their countermeasures, followed by proposed research directions and open issues