Browsing by Author "Mohammad, Zeyad"

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AN EFFICIENT AND SECURE THREE-PASS AUTHENTICATED KEY AGREEMENT ELLIPTIC CURVE BASED PROTOCOL
(2011-03-01)
Mohammad, Zeyad
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Hsu, Chien-Lung
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Chen, Yaw-Chung
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Lo, Chi-Chun
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資訊管理與財務金融系註：原資管所+財金所
Key agreement protocols are a fundamental building block of cryptography to establish a common secret key over public network. We propose an efficient and secure three-pass authenticated key agreement protocol based on elliptic curve where three-pass protocols have significant advantages over two-pass in terms of security properties and applications. The three-pass protocols can prevent denial of service attacks in complex and unpredictable communication environments such as wireless networks and Internet. We show the proposed protocol can withstand a stronger adversary under eCK security model by using a trick in its block of hashing a static secret key with an ephemeral secret key. Furthermore, it can provide an assurance of the identity authentication of its partner, thus it can withstand non-repudiation attacks. Therefore, it is suitable for electronic commerce to provide non-repudiation services. By comparing the security and computational complexity of the proposed protocol with other existing protocols in our study, we show that the proposed protocol not only satisfies all security attributes but also obtains computational efficiency with a cost of 3 point multiplications.
Cryptanalysis and Enhancement of Two-pass Authenticated Key Agreement with Key Confirmation Protocols
(2010-05-01)
Mohammad, Zeyad
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Chen, Yaw-Chung
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Hsu, Chien-Lung
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Lo, Chi-Chun
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資訊管理與財務金融系註：原資管所+財金所
In 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 Pours 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 indirect way. (iii) It can withstand denial of service attacks. In addition, we also propose a derivation one-pass protocol from the proposed two-pass protocol to fit a one-way communication channel, which is suitable for mobile stations and electronic business transactions. The security and the computational complexities of the proposed two protocols outperform those of previously proposed protocols.
Cryptanalysis of a Secure and Efficient Three-Pass Authenticated Key Agreement Protocol Based on Elliptic Curves
(2013-03-01)
Mohammad, Zeyad
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Hsu, Chien-Lung
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Chen, Yaw-Chung
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Lo, Chi-Chun
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資訊工程學系
Key agreement protocols are a foundation for distributing a common secret key over an insecure network. Lim et al. proposed a secure and efficient three-pass authenticated key agreement protocol based on elliptic curves to overcome the vulnerability of Yoon-Yoo protocol under extended Canetti-Krawczyk security model. In this letter, we show that Lim et al.'s protocol is vulnerable to leakage of responder's static private key by malicious party and cannot withstand known key security resilience attacks.
Vulnerability of an Improved Elliptic Curve Diffie-Hellman Key Agreement And Its Enhancement
(2009)
Mohammad, Zeyad
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Lo, Chi-Chun
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
Authenticated key agreement protocols are a foundation for delivering an authenticated session key between the intended two-party participants from a set of parties over an insecure network. Wang et al proposed protocol ECKE-1N to overcome KCI-R attacks in ECKE-1 as an implicit authenticated key agreement protocol based on Diffie-Hellman elliptic curve. In this paper, we show that ECKE-1N is vulnerable to both leakage of ephemeral private keys and KCI-R attacks. We present an enhanced protocol EECKE-1N, which can withstand KCI-R attacks and revelations both of ephemeral keys. Furthermore, EECKE-1N can provide desirable security proprieties.