Cryptanalysis and improvement of an efficient certificateless signature scheme

In traditional digital signature schemes, certificates signed by a trusted party are required to ensure the authenticity of the public key. In Asiacrypt 2003, the concept of certificateless signature scheme was introduced. The advantage of certificate-less public key cryptography successfully eliminates the necessity of certificates in the traditional public key cryptography and simultaneously solves the inherent key escrow problem suffered in identity-based cryptography. Recently, Yap et al. proposed an efficient certificateless signature scheme and claimed that their scheme is existentially unforgeable in the random oracle model. In this paper, we show that the certificateless signature scheme proposed by Yap et al. is insecure against public key replacement attacks. Furthermore, we propose an improved certificateless signature scheme, which is existentially unforgeable against adaptive chosen message attacks under the computational Diffie-Hellman assumption in the random oracle model and provide the security proof of the proposed scheme

Toward an RSU-unavailable lightweight certificateless key agreement scheme for VANETs

Vehicle ad-hoc networks have developed rapidly these years, whose security and privacy issues are always concerned widely. In spite of a remarkable research on their security solutions, but in which there still lacks considerations on how to secure vehicle-to-vehicle communications, particularly when infrastructure is unavailable. In this paper, we propose a lightweight certificateless and one-round key agreement scheme without pairing, and further prove the security of the proposed scheme in the random oracle model. The proposed scheme is expected to not only resist known attacks with less computation cost, but also as an efficient way to relieve the workload of vehicle-to-vehicle authentication, especially in no available infrastructure circumstance. A comprehensive evaluation, including security analysis, efficiency analysis and simulation evaluation, is presented to confirm the security and feasibility of the proposed scheme

Certificateless Signature Scheme Based on Rabin Algorithm and Discrete Logarithm

Certificateless signature can effectively immue the key escrow problem in the identity-based signature scheme. But the security of the most certificateless signatures usually depends on only one mathematical hard problem, which makes the signature vulnerable when the underlying hard problem has been broken. In order to strengthen the security, in this paper, a certificateless signature whose security depends on two mathematical hard problems, discrete logarithm and factoring problems, is proposed. Then, the proposed certificateless signature can be proved secure in the random oracle, and only both of the two mathematical hard problems are solved, can the proposed signature be broken. As a consequence, the proposed certificateless signature is more secure than the previous signatures. On the other hand, with the pre-computation of the exponential modular computation, it will save more time in the signature signing phase. And compared with the other schemes of this kind, the proposed scheme is more efficient

A Computationally Efficient Online/Offline Signature Scheme for Underwater Wireless Sensor Networks

Underwater wireless sensor networks (UWSNs) have emerged as the most widely used wireless network infrastructure in many applications. Sensing nodes are frequently deployed in hostile aquatic environments in order to collect data on resources that are severely limited in terms of transmission time and bandwidth. Since underwater information is very sensitive and unique, the authentication of users is very important to access the data and information. UWSNs have unique communication and computation needs that are not met by the existing digital signature techniques. As a result, a lightweight signature scheme is required to meet the communication and computa‑ tion requirements. In this research, we present a Certificateless Online/Offline Signature (COOS) mechanism for UWSNs. The proposed scheme is based on the concept of a hyperelliptic curves cryptosystem, which offers the same degree of security as RSA, bilinear pairing, and elliptic curve cryptosystems (ECC) but with a smaller key size. In addition, the proposed scheme was proven secure in the random oracle model under the hyperelliptic curve discrete logarithm problem. A se‑ curity analysis was also carried out, as well as comparisons with appropriate current online/offline signature schemes. The comparison demonstrated that the proposed scheme is superior to the exist‑ ing schemes in terms of both security and efficiency. Additionally, we also employed the fuzzy‑based Evaluation‑based Distance from Average Solutions (EDAS) technique to demonstrate the effective‑ ness of the proposed scheme.publishedVersio

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

An Efficient Online/Offline Signcryption Scheme for Internet of Things in Smart Home

publishedVersio

An Efficacious and Secure Registration for Internet Protocol Mobility

For the ample development of mobile internet protocol (IP) technology and the recurrent movement of a mobile device, it is necessary for the mobile device to inform their home network where initially registered through an efficient and secured procedure against any sort of attacks. The procedure of registration for IP mobility by the portable system must have a better performance by providing a certain level of security, such as authentication, integrity, replay attack protection, and location privacy. All at once, the extreme security in the registration of IP mobility may cause long registration time, principally for real-time systems. This paper mainly deals with a balanced effort for secure and efficient registration procedure which gives better security and efficiency in terms of registration delay. The proposed work provides an easy and fast registration procedure and lessens the registration delay through the usage of an identity based authenticated key exchange scheme that eliminates expensive pairing operations. The proposed protocol is verified by using AVISPA tool. The performance evaluation reveals that the proposed protocol significantly outperforms the existing protocols in terms of the registration delay.Defence Science Journal, 2013, 63(5), pp.502-507, DOI:http://dx.doi.org/10.14429/dsj.63.400