An efficient certificateless authenticated key agreement protocol without bilinear pairings

Certificateless public key cryptography simplifies the complex certificate management in the traditional public key cryptography and resolves the key escrow problem in identity-based cryptography. Many certificateless authenticated key agreement protocols using bilinear pairings have been proposed. But the relative computation cost of the pairing is approximately twenty times higher than that of the scalar multiplication over elliptic curve group. Recently, several certificateless authenticated key agreement protocols without pairings were proposed to improve the performance. In this paper, we propose a new certificateless authenticated key agreement protocol without pairing. The user in our just needs to compute five scale multiplication to finish the key agreement. We also show the proposed protocol is secure in the random oracle model

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

Secure pairing-free two-party certificateless authenticated key agreement protocol with minimal computational complexity

Key agreement protocols play a vital role in maintaining security in many critical applications due to the importance of the secret key. Bilinear pairing was commonly used in designing secure protocols for the last several years; however, high computational complexity of this operation has been the main obstacle towards its practicality. Therefore, implementation of Elliptic-curve based operations, instead of bilinear pairings, has become popular recently, and pairing-free key agreement protocols have been explored in many studies. A considerable amount of literatures has been published on pairing-free key agreement protocols in the context of Public Key Cryptography (PKC). Simpler key management and non-existence of key escrow problem make certificateless PKC more appealing in practice. However, achieving certificateless pairing-free two-party authenticated key agreement protocols (CL-AKA) that provide high level of security with low computational complexity, remains a challenge in the research area. This research presents a secure and lightweight pairingfree CL-AKA protocol named CL2AKA (CertificateLess 2-party Authenticated Key Agreement). The properties of CL2AKA protocol is that, it is computationally lightweight while communication overhead remains the same as existing protocols of related works. The results indicate that CL2AKA protocol is 21% computationally less complex than the most efficient pairing-free CL-AKA protocol (KKC-13) and 53% less in comparison with the pairing-free CL-AKA protocol with highest level of security guarantee (SWZ-13). Security of CL2AKA protocol is evaluated based on provable security evaluation method under the strong eCK model. It is also proven that the CL2AKA supports all of the security requirements which are necessary for authenticated key agreement protocols. Besides the CL2AKA as the main finding of this research work, there are six pairing-free CL-AKA protocols presented as CL2AKA basic version protocols, which were the outcomes of several attempts in designing the CL2AKA

A Strong and Efficient Certificateless Digital Signature Scheme

This paper extends the certificateless public key infrastructure model that was proposed by Hassouna et al by proposing new digital signature scheme to provide true non-repudiation, the proposed signature scheme is short and efficient, it is also has strength point that the KGC has no contribution in signature generation/verification process, therefore any compromise of the KGC does not affect the non-repudiation service of the system. Furthermore, even the KGC cannot do signature forgery by (temporary) replacing the user’s public key

Provably-Secure (Chinese Government) SM2 and Simplified SM2 Key Exchange Protocols

We revisit the SM2 protocol, which is widely used in Chinese commercial applications and by Chinese government agencies. Although it is by now standard practice for protocol designers to provide security proofs in widely accepted security models in order to assure protocol implementers of their security properties, the SM2 protocol does not have a proof of security. In this paper, we prove the security of the SM2 protocol in the widely accepted indistinguishability-based Bellare-Rogaway model under the elliptic curve discrete logarithm problem (ECDLP) assumption. We also present a simplified and more efficient version of the SM2 protocol with an accompanying security proof

An Authenticated Key Agreement Scheme using Vector Decomposition

Encryption using vector decomposition problem (VDP) on higher dimensional vector spaces is a novel method in cryptography. Yoshida has shown that the VDP on a two-dimensional vector space is at least as hard as the computational Diffie-Hellman problem on a one-dimensional subspace under certain conditions. Steven Galbraith has shown that for certain curves, the VDP is at most as hard as the discrete logarithm problem on a one-dimensional subspace. Okomoto and Takashima proposed encryption scheme and signature schemes using VDP. An authenticated key agreement scheme using vector decomposition problem is proposed in this pape

A performance improved certificateless key agreement scheme over elliptic curve based algebraic groups

Due to the importance of key in providing secure communication, various Key Agreement protocols have been proposed in the recent years. The latest generation of Public Key Cryptosystems (PKC) called Certificateless PKC played an important role in the transformation of Key Agreement protocols. In this scientific area, several Key Agreement protocols have been proposed based on Bilinear Pairings. However, pairing operation is known as an expensive cryptographic function. Hence, utilization of pairing operation in the mentioned works made them complex from overall computational cost perspective. In order to decrease the computational cost of Key Agreement protocols, several Certificateless Key Agreement protocols have been proposed by the use of operations over Elliptic Curve based Algebraic Groups instead of using Bilinear Pairings. In this paper, we propose a Pairing-free Certificateless two-party Key Agreement protocol. Our results indicate that our secure protocol is significantly more lightweight than existing related works