• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2375-2393
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• 2016

Key agreement is paramount in secure wireless communications. A promising approach to address key agreement schemes is to extract secure keys from channel characteristics. However, because channels lack randomness, it is difficult for wireless networks with stationary communicating terminals to generate robust keys. In this paper, we propose a Robust Secure Key Agreement (RSKA) scheme from Received Signal Strength (RSS) in stationary wireless networks. In order to mitigate the asymmetry in RSS measurements for communicating parties, the sender and receiver normalize RSS measurements and quantize them into q-bit sequences. They then reshape bit sequences into new l-bit sequences. These bit sequences work as key sources. Rather than extracting the key from the key sources directly, the sender randomly generates a bit sequence as a key and hides it in a promise. This is created from a polynomial constructed on the sender's key source and key. The receiver recovers the key by reconstructing a polynomial from its key source and the promise. Our analysis shows that the shared key generated by our proposed RSKA scheme has features of high randomness and a high bit rate compared to traditional RSS-based key agreement schemes.

• Journal of Communications and Networks
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• v.14 no.4
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• pp.418-428
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• 2012

With the requirement for providing multiple levels of access control for group members, many group key management schemes designed for hierarchical access control have been put forward. However, most of these schemes focus on the efficiency of group key establishment and rekeying in centralized environments. This paper proposes an integrated group key agreement (IGK) scheme for contributory environments. The IGK scheme employs the integrated key graph to remove key redundancies existing in single key trees, and reduces key establishment and rekeying time while providing hierarchical access control. Performance analyses and simulations conducted with respect to computation and communication overheads indicate that our proposed IGK scheme is more efficient than the independent group key agreement scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1C
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• pp.25-34
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• 2005

Girault proposed a key agreement protocol based on his new idea of self-certified public key. Later Rueppel and Oorschot showed variants of the Girault scheme. All of these key agreement protocols inherit positive features of self-certified public key so that they can provide higher security and smaller communication overhead than key agreement protocols not based on self-certified public key. Even with such novel features, rigorous security analysis of these protocols has not been made clear yet. In this paper, we give rigorous security analysis of key agreement protocols based on self-certified public key. We use reduction among functions for security analysis and consider several kinds of active attacker models such as active impersonation attack, key-compromise impersonation attack, forward secrecy and known key security.

• Communications of the Korean Mathematical Society
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• v.18 no.1
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• pp.169-179
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• 2003

In this paper, we propose multiparty key agreement protocols by generalizing the Blom's scheme based on 2 variable polynomials. Especially we develop three party and four party key agreement schemes with security. The advantage of the new schemes is to have small demands on storage space.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.256-259
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• 2003

This paper presents mutual authentication scheme between user and network on mobile communications using public key scheme based on counter, and simultaneously shows key agreement between user and user using random number for secure communications. This is also a range of possible solutions to authentication and key agreement problem-authentication and key agreement protocol based on nonce and count, and secure end-to-end protocol based on the function Y=f(.)$\^$1/, C$\^$i/ is count of user I, and f(.) is one way function.

• ETRI Journal
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• v.45 no.6
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• pp.1090-1102
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• 2023

Authenticated multiple key agreement (AMKA) protocols provide participants with multiple session keys after one round of authentication. Many schemes use Diffie-Hellman or authenticated key agreement schemes that rely on hard integer factorizations that are vulnerable to quantum algorithms. Lattice cryptography provides quantum resistance to authenticated key agreement protocols, but the certificate always incurs excessive public key infrastructure management overhead. Thus, a lightweight lattice-based secure system is needed that removes this overhead. To answer this need, we provide a two-party lattice- and identity-based AMKA scheme based on bilateral short integer or computational bilateral inhomogeneous small integer solutions, and we provide a security proof based on the random oracle model. Compared with existing AMKA protocols, our new protocol has higher efficiency and stronger security.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.5
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• pp.297-301
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• 2013

Key agreement protocols allow multi-parties exchanging public information to create a common secret key that is known only to those entities over an insecure network. Since Joux first published the pairing-based one round tripartite key agreement protocol, many authenticated protocols have been proposed. Unfortunately, many of them have been broken while others have been shown to be deficient in some desirable security attributes. In 2004, Cheng et al. presented two protocols aimed at strengthening Shim's certificate-based and Zhang et al.'s tripartite identity-based protocols. This paper reports that 1) In Cheng et al.'s identity-based protocol, an adversary can extract long-term private keys of all the parties involved; and 2) Cheng et al.'s certification-based protocol is weak against key integrity attacks. This paper suggests possible remedies for the security flaws in both protocols and then presents a modified Cheng et al.'s identity-based, one-round tripartite protocol that is more secure than the original protocol.

• Journal of Internet Computing and Services
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• v.4 no.6
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• pp.95-102
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• 2003

The Diffle-Hellman Key Exchange scheme can produce a common session key between the two communicators, but its problem is that it makes a man-in-the middle attack possible. To solve problems like these, several protocols have been put forward, and the Simple Authenticated Key Agreement (SAKA) Protocol is among them. This protocol has been suggested by Seo-Sweeney, Tseng, and Ku-Wang, respectively, In this paper, we will put forward a new protocol that has been improved from all the original protocols mentioned above, but is still safe and quick to use, While the existing protocol divides the common session key production stage and the verification stage, the protocol suggested in this paper takes care of both of those stages simultaneously, therefore improving the processing performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.12
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• pp.2392-2402
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• 2011

In order to protect some important information communicated through an insecure network, a common hidden key must be used. One can produce the common hidden key using key agreement protocols; and this helps to have high security in modern data networks. Today, the designers of public key cryptography protocols try to set the public identity of a system's users (like their email addresses) as their public key. This not only makes a cryptographic protocol more efficient but also decreases its cost. These protocols are called "identity-based". In this article, an identity-based multiple key agreement scheme will be presented; this scheme uses the challenge-response method to do the verification. While the number of random values produced in our scheme is the same as other schemes, the number of keys generated in this scheme is much more than what many other key agreement schemes produce,. Therefore, we will have less computational complexities campered with other schems. In this paper, we consider the security of our scheme and consequently, we will show that it satisfies many security conditions such as strong security.

• Communications of the Korean Mathematical Society
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• v.20 no.4
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• pp.849-859
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• 2005

We present a new identity based authenticated key agreement protocol from pairings satisfying the required security attributes. The security of our protocol is based on the bilinear Diffie- Hellman assumption.