An authenticated key agreement (AKA) protocol is extremely essential to secure communications over insecure public networks. It enables the communication parties to securely set up a shared session key in present of the malicious attackers. Certificate-based cryptography (CBC) is a novel public-key cryptographic primitive that has many attractive merits. It solves the certificate revocation problem in conventional public-key cryptography and the key-escrow problem in identity-based cryptography. Till now, four AKA protocols have been proposed in the setting of CBC. However, all of them adopt the costly bilinear pairings and are not suitable for the devices which have limited computing resources and battery power. So, it is interesting and worthwhile to design a certificate-based AKA protocol without using the bilinear pairings. In this paper, we develop a pairing-free certificate-based AKA protocol. The proposed protocol is proven secure under the classic computational Diffie-Hellman assumption in the random oracle model. Compared with the previous pairing-based certificate-based AKA protocols, the proposed protocol enjoys obvious advantage in the computation efficiency.DOI: http://dx.doi.org/10.5755/j01.itc.46.3.14968
An authenticated key agreement (AKA) protocol is extremely essential to secure communications over insecure public networks. It enables the communication parties to securely set up a shared session key in present of the malicious attackers. Certificate-based cryptography (CBC) is a novel public-key cryptographic primitive that has many attractive merits. It solves the certificate revocation problem in conventional public-key cryptography and the key-escrow problem in identity-based cryptography. Till now, four AKA protocols have been proposed in the setting of CBC. However, all of them adopt the costly bilinear pairings and are not suitable for the devices which have limited computing resources and battery power. So, it is interesting and worthwhile to design a certificate-based AKA protocol without using the bilinear pairings. In this paper, we develop a pairing-free certificate-based AKA protocol. The proposed protocol is proven secure under the classic computational Diffie-Hellman assumption in the random oracle model. Compared with the previous pairing-based certificate-based AKA protocols, the proposed protocol enjoys obvious advantage in the computation efficiency.DOI: http://dx.doi.org/10.5755/j01.itc.46.3.14968
Certificateless authenticated key agreement (CL-AKA) protocols neither suffer from a heavy certificate managementburden nor have the key escrow problem. Recently, many CL-AKA protocols have been proposed. However, manyof them need expensive bilinear pairings, which cannot be suitable for low-power devices such as sensors or mobile devices.To be implemented in practice, some pairing-free CL-AKA protocols have been built, however, very few of these pairing-freeCL-AKA protocols can be secure in the eCK model. In this paper, we present a pairing-free CL-AKA protocol and providea full proof of its security in the eCK model. Compared with the existing CL-AKA protocols, our protocol is more secure,practical and suitable for low-power devices.DOI: http://dx.doi.org/10.5755/j01.itc.42.2.1689
Certificate-based cryptography is a new public-key cryptographic paradigm that has very appealing features, namely it simplifies the certificate management problem in traditional public key cryptography while eliminating the key escrow problem in identity-based cryptography. So far, three authenticated key agreement (AKA) protocols in the setting of certificate-based cryptography have been proposed in the literature. Unfortunately, none of them are secure under the public key replacement (PKR) attack. In this paper, we first present a security model for certificate-based AKA protocols that covers the PKR attacks. We then explore the existing three certificate-based AKA protocols and show the concrete attacks against them respectively. To overcome the weaknesses in these protocols, we propose a new certificate-based AKA protocol and prove its security strictly in the random oracle model. Performance comparison shows that the proposed protocol outperforms all the previous certificate-based AKA protocols.
Internet of Things (IoT) applications have been increasingly developed. Authenticated key agreement (AKA) plays an essential role in secure communication in IoT applications. Without the PKI certificate and high time-complexity bilinear pairing operations, identity-based AKA (ID-AKA) protocols without pairings are more suitable for protecting the keys in IoT applications. In recent years, many pairing-free ID-AKA protocols have been proposed. Moreover, these protocols have some security flaws or relatively extensive computation and communication efficiency. Focusing on these problems, the security analyses of some recently proposed protocols have been provided first. We then proposed a family of eCK secure ID-AKA protocols without pairings to solve these security problems, which can be applied in IoT applications to guarantee communication security. Meanwhile, the security proofs of these proposed ID-AKA protocols are provided, which show they can hold provable eCK security. Some more efficient instantiations have been provided, which show the efficient performance of these proposed ID-AKA protocols. Moreover, comparisons with similar schemes have shown that these protocols have the least computation and communication efficiency at the same time.
Certificateless public key cryptography has appealing features,namely it does not require the use of certificates and does not have a private key escrow feature.This paper describes a certificateless key agreement protocol based on bilinear pairings.The identity authentication in the protocol depends on a digital signature scheme.This paper proves the security of the signature scheme.The results show that in the random oracle model with the discrete logarithm assumption,the signature scheme resists existential forgeries against adaptive chosen-message attacks.The results farther show that the protocol preserves the desired security properties,including known-key security,unknown key-share resilience,perfect forward secrecy,key-compromise impersonation resilience and leakage of ephemeral private key resilience.The protocol requires much lower computation overhead than related protocols,since it uses fewer bilinear pairing operations and no modular exponentiation.
Key agreement is one of the fundamental cryptographic primitives in public key cryptography. So far several certificateless two-party authenticated key agreement (CL-T-AKA) protocols have been proposed. However, all these protocols are based on bilinear map and most of them are without formal security proof. In this paper, we present a new formal security model of CL-T-AKA protocols and bring forward the first two-party key agreement protocol without the computation of expensive bilinear map. Our protocol is secure under the security model assuming the Gap-DH problem is intractable. With respect to efficiency, our protocol requires a single round of communication in which each party sends only one group element, and needs only five modular exponentiation computations. In addition, we point out that an existing certificateless two-party key agreement protocol cannot resist man-in-the-middle attack.
Through the group key agreement, all group members could negotiate a common session key which is used in later secure communication.While simple GKA cannot provide enough security to resist the adversary's attack, and the malicious damage during the agreement makes the authenticated key agreement particularly important.In identity-based authentication, user's unique identity information is used as the public key, which makes it exempt from a series of management of the certification in public-key infrastructure.Thereby, the identity-based key agreement can simplify the key management procedures and reduce the risk of failure at the certification authority.Recently, several identity-based group key agreement protocols have been proposed, however most of them are either vulnerable to impersonation and replay attack or inefficient and unscalable.This paper proposes a novel authenticated group key agreement protocol which is based on bilinear pairings.It needs two rounds to negotiate the session key, and the low computational complexity makes the protocol efficient and scalable.Meanwhile, our protocol also ensures the forward and backward secrecy and the key independence.Under the Decisional Diffie-Hellman assumption, our protocol is proved to be secure against the adversary. 1.