• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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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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• 제14권4호
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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.

• 한국통신학회논문지
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• 제30권1C호
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• pp.25-34
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• 2005

Girault는 자체 인증 공개키(self-certified public key)의 개념과 함께 이를 사용한 키 분배 프로토롤을 제안하였고 후에 Rueppel과 Oorschot는 이를 변형한 프로토콜들을 제안하였다. 자체인증 공개키에 기반한 키 분배 프로토콜은 사용자가 자신의 비밀키를 직접 선택하므로 개인식별 정보에 기반한 방식의 문제점으로 지적되었던 신뢰센터가 임의의 사용자로 위장할 수 있는 문제를 해결할 수 있고, 또한 메모리와 계산량을 감소시킬 수 있다는 장점이 있다. 그러나, 키 분배 프로토콜의 안전성에 대한 구체적인 증명은 아직까지 미흡한 실정이다. 본 논문에서는 지금까지 제안된 자체인증 공개키에 기반한 키분배 프로토콜에 대한 능동적 공격자 환경에서의 구체적인 안전성 분석을 수행하고자 한다. 본 논문에서 고려하는 공격은 active impersonation 공격, key-compromise impersonation 공격, forward secrecy, known key secuity이며, 안전성 증명에는 수학적 귀착 이론을 이용한다.

• 대한수학회논문집
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• 제18권1호
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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.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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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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• 제45권6호
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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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• 제2권5호
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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.

• 인터넷정보학회논문지
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• 제4권6호
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• pp.95-102
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• 2003

Diffle-Hellman 키 교환 방법은 두 통신자간에 공통 세션키를 생성할 수 있으나, 중간자 공격 (mon-in-the-middle attack)이 가능하다는 문제점을 안고 있다. 이러한 문제점을 해결하기 위하여 여러 가지 프로토콜들이 제안되었는데 Simple Authenticated Key Agreement (SAKA) 프로토콜도 그 중 하나이다. 이 프로토콜은 Seo-Sweeney, Tseng, Ku-Wang 등에 의하여 각각 제안된 바 있는데, 본 논문에서는 이들 프로토콜을 종합적으로 개선하여 안전하면서도 수행성능이 개선된 새로운 프로토콜을 제안한다. 기존 프로토콜들이 공통 세션키 생성단계와 검증단계를 구분하여 이루어지는 것에 비하여 본 논문에서 제안하는 프로토콜은 생성 단계와 검증 단계를 한꺼번에 처리함으로써, 수행시간 단축의 효과를 갖는다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권12호
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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.

• 대한수학회논문집
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• 제20권4호
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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.