Browsing by Author "Hsu, Chien-Lung"

Now showing 1 - 5 of 5

AN EFFICIENT AND SECURE THREE-PASS AUTHENTICATED KEY AGREEMENT ELLIPTIC CURVE BASED PROTOCOL
(2011-03-01)
Mohammad, Zeyad
;
Hsu, Chien-Lung
;
Chen, Yaw-Chung
;
Lo, Chi-Chun
;
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
;
Chen, Yaw-Chung
;
Hsu, Chien-Lung
;
Lo, Chi-Chun
;
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
;
Hsu, Chien-Lung
;
Chen, Yaw-Chung
;
Lo, Chi-Chun
;
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.
EFFICIENT VERIFIER-BASED AUTHENTICATED KEY AGREEMENT PROTOCOL FOR THREE PARTIES
(2010-02-01)
Wu, Tzong-Sun
;
Lin, Han-Yu
;
Hsu, Chien-Lung
;
Chang, Kuo-Yi
;
資訊工程學系
Authenticated key agreement protocols for three parties enable two clients to establish a secure communication channel through an authentication server. Generally speaking, there are two approaches to achieve this purpose. One is to issue a common session key for both clients by the key distribution center (KDC). The other is to use public key cryptosystems and the encrypted key exchange (EKE) protocol to encrypt the transmitted messages and then further derive a common session key. Recently, lots of researches on authenticated key agreement protocol for three parties use the servers public key to ensure the security of transmitted messages. Yet, the approach obviously has some drawbacks, such as increasing the cost of key management for each client. Hence, the demand for secure protocols without the server's public key comes out. In this paper, we propose an efficient verifier-based authenticated key agreement for three parties. The proposed protocol can resist the password guessing attack and other existential attacks. Moreover, compared with previous works, the proposed one also has lower computational costs.
Improved convertible authenticated encryption scheme with provable security
(2011-07-01)
Lin, Han-Yu
;
Hsu, Chien-Lung
;
Huang, Shih-Kun
;
資訊工程學系
;
Department of Computer Science
Convertible authenticated encryption (CAE) schemes allow a signer to produce an authenticated ciphertext such that only a designated recipient can decrypt it and verify the recovered signature. The conversion property further enables the designated recipient to reveal an ordinary signature for dealing with a later dispute over repudiation. Based on the EIGamal cryptosystem, in 2009, Lee et al. proposed a CAE scheme with only heuristic security analyses. In this paper, we will demonstrate that their scheme is vulnerable to the chosen-plaintext attack and then further propose an improved variant. Additionally, in the random oracle model, we prove that the improved scheme achieves confidentiality against indistinguishability under adaptive chosen-ciphertext attacks (IND-CCA2) and unforgeability against existential forgery under adaptive chosen-message attacks (EF-CMA). (C) 2011 Elsevier B.V. All rights reserved.