Summary Hao proposed the YAK as a robust key agreement based on public‐key authentication, and the author claimed that the YAK protocol withstands all known attacks and therefore is secure against an extremely strong adversary. However, Toorani showed the security flaws in the YAK protocol. This paper shows that the YAK protocol cannot withstand the known key security attack, and its consequences lead us to introduce a new key compromise impersonation attack, where an adversary is allowed to reveal both the shared static secret key between two‐party participation and the ephemeral private key of the initiator party in order to mount this attack. In addition, we present a new security model that covers these attacks against an extremely strong adversary. Moreover, we propose an improved YAK protocol to remedy these attacks and the previous attacks mentioned by Toorani on the YAK protocol, and the proposed protocol uses a verification mechanism in its block design that provides entity authentication and key confirmation. Meanwhile, we show that the proposed protocol is secure in the proposed formal security model under the gap Diffie‐Hellman assumption and the random oracle assumption. Moreover, we verify the security of the proposed protocol and YAK protocol by using an automatic verification method such as the Scyther tool, and the verification result shows that the security claims of the proposed protocol are proven, in contrast to those of the YAK protocol, which are not proven. The security and performance comparisons show that the improved YAK protocol outperforms previous related protocols.
This paper discusses public-key authenticated key agreement protocols. First, we critically analyze several authenticatedkey agreement protocols and uncover various theoretical and practical flaws. In particular, we present two new attacks onthe HMQV protocol, which is currently being standardized by IEEE P1363. These attacks suggest the caution one shouldtake when interpreting theoretical results from a formal model. We further point out that many of the protocol failures inthe past are caused by sidestepping an important engineering principle, namely “Do not assume that a message you receivehas a particular form (such as g^r for known r) unless you can check this”. Constructions in the past generally resistedthis principle on the grounds of efficiency: checking the knowledge of the exponent is commonly seen as too expensive.In a concrete example, we demonstrate how to effectively integrate the zero-knowledge proof primitive into the protocoldesign and meanwhile achieve good efficiency. Our new key agreement protocol, YAK, has comparable computationalefficiency to the MQV and HMQV protocols with clear advantages on security. Among all the related techniques, ourprotocol appears to be the simplest so far. We believe simplicity is also an important engineering principle.
As the fundamental building block for secure communication in the open network, authenticated key agreement protocols are usually constructed in the public key setting. Certificateless public key cryptography combines the advantage of the identity-based public key cryptography (ID-PKC) and the traditional PKI. In this paper, we present a secure and efficient two-party authenticated key agreement protocol based on the efficient certificateless public key encryption scheme due to Cheng and Comley. Security analysis shows that it achieves perfect forward secrecy, PKG forward secrecy and almost all the other known security attributes for authenticated key agreement protocol, such as known-key secrecy, key-compromise impersonation resilience, unknown key-share resilience, known session-specific temporary information security, message independence and no key control. Compared to other comparable schemes, it is more secure and has nice efficiency.
AbstractIn NRSC24, Elkamchouchi et al. proposed a new approach for key controlled agreement to provide key control in the Pour public key distribution system. In NRSC25, they further proposed an efficient and confirmed protocol for authenticated key agreement to provide forward secrecy in their previously proposed protocol. This paper, however, will show that Pour’s protocol and Elkamchouchi et al.’s two protocols cannot withstand key compromise impersonation resilience, and man-in-the-middle attacks, and do not have perfect forward secrecy resilience. To eliminate the pointed out security leaks, we further propose a new two-pass authenticated key agreement with a key confirmation protocol. The proposed protocol has the following properties: (i) it is proved to be secure against above attacks and stronger adversary attacks, and provides the desirable security properties as a three-pass authenticated key agreement protocol. (ii) It can provide entity authentication and assurance for key reception in an ind...
Authenticated key agreement protocol is the fundamental building block for secure communication in the open network to ensure authentication and confidentiality of e-commerce and e-government applications. Certificateless public key cryptography combines the advantage of the identity-based public key cryptography (ID-PKC) and the traditional PKI. In this paper, we present a secure and efficient two-party authenticated key agreement protocol based on an efficient and secure certificateless public key encryption scheme. It achieves almost all the known security attributes for authenticated key agreement protocol, such as perfect forward secrecy, PKG forward secrecy, key-compromise impersonation resilience, unknown key-share resilience, message independence and no key control. Compared to other comparable schemes, it is more secure and has nice efficiency.