109 research outputs found

    ID-based tripartite Authenticated Key Agreement Protocols from pairings

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    This paper proposes ID-based tripartite authenticated key agreement protocols. The authenticated three party key agreement protocols from pairings [15], and the ID-based two party authenticated key agreement protocol [13] are studied. These two protocols are taken as the basis for designing three new ID-based tripartite authenticated key agreement protocols. The security properties of all these protocols are studied listing out the possible attacks on them. Further, these protocols are extended to provide key confirmation

    Cryptographic Schemes based on Elliptic Curve Pairings

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    This thesis introduces the concept of certificateless public key cryptography (CLPKC). Elliptic curve pairings are then used to make concrete CL-PKC schemes and are also used to make other efficient key agreement protocols. CL-PKC can be viewed as a model for the use of public key cryptography that is intermediate between traditional certificated PKC and ID-PKC. This is because, in contrast to traditional public key cryptographic systems, CL-PKC does not require the use of certificates to guarantee the authenticity of public keys. It does rely on the use of a trusted authority (TA) who is in possession of a master key. In this respect, CL-PKC is similar to identity-based public key cryptography (ID-PKC). On the other hand, CL-PKC does not suffer from the key escrow property that is inherent in ID-PKC. Applications for the new infrastructure are discussed. We exemplify how CL-PKC schemes can be constructed by constructing several certificateless public key encryption schemes and modifying other existing ID based schemes. The lack of certificates and the desire to prove the schemes secure in the presence of an adversary who has access to the master key or has the ability to replace public keys, requires the careful development of new security models. We prove that some of our schemes are secure, provided that the Bilinear Diffie-Hellman Problem is hard. We then examine Joux’s protocol, which is a one round, tripartite key agreement protocol that is more bandwidth-efficient than any previous three-party key agreement protocol, however, Joux’s protocol is insecure, suffering from a simple man-in-the-middle attack. We show how to make Joux’s protocol secure, presenting several tripartite, authenticated key agreement protocols that still require only one round of communication. The security properties of the new protocols are studied. Applications for the protocols are also discussed

    Two-Party Threshold Key Agreement Protocol for MANETs using Pairings

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    In MANET environment, the nodes are mobile i.e., nodes move in and out dynamically. This causes difficulty in maintaining a central trusted authority say Certification Authority CA or Key Generation Centre KCG. In addition most of cryptographic techniques need a key to be shared between the two communicating entities. So to introduce security in MANET environment, there is a basic need of sharing a key between the two communicating entities without the use of central trusted authority. So we present a decentralized two-party key agreement protocol using pairings and threshold cryptography ideas. Our model is based on Joux2019;s three-party key agreement protocol which does not authenticate the users and hence is vulnerable to man-in-the-middle attack. This model protects from man-in-the-middle attack using threshold cryptography

    Two secure non-symmetric role Key-Agreement protocols

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    Recently, some two-party Authenticated Key Agreement protocols over elliptic curve based algebraic groups, in the context of Identity-Based cryptography have been proposed. The main contribution of this category of protocols is to reduce the complexity of performing algebraic operations through eliminating the need to using Bilinear Pairings. In this paper, we proposed two novel Identity-Based Authenticated Key Agreement protocols over non-symmetric role participants without using Bilinear Pairings. The results show that our proposed schemes beside of supporting security requirements of Key Agreement protocols, require a subset of operations with low complexity in compare with related protocols in this scientific area

    Comments: Insider attack on Cheng et al.\u27s pairing-based tripartite key agreement protocols

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    Recently, Cheng et al. proposed two tripartite key agreement protocols from pairings: one is certificate-based and the other is identity-based (ID-based). In this article, we show that the two schemes are vulnerable to the insider impersonation attack and the ID-based scheme even discloses the entities¡¦ private keys. Solutions to this problem are discussed

    Sufficient condition for ephemeral key-leakage resilient tripartite key exchange

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    17th Australasian Conference on Information Security and Privacy, ACISP 2012; Wollongong, NSW; Australia; 9 July 2012 through 11 July 2012Tripartite (Diffie-Hellman) Key Exchange (3KE), introduced by Joux (ANTS-IV 2000), represents today the only known class of group key exchange protocols, in which computation of unauthenticated session keys requires one round and proceeds with minimal computation and communication overhead. The first one-round authenticated 3KE version that preserved the unique efficiency properties of the original protocol and strengthened its security towards resilience against leakage of ephemeral (session-dependent) secrets was proposed recently by Manulis, Suzuki, and Ustaoglu (ICISC 2009). In this work we explore sufficient conditions for building such protocols. We define a set of admissible polynomials and show how their construction generically implies 3KE protocols with the desired security and efficiency properties. Our result generalizes the previous 3KE protocol and gives rise to many new authenticated constructions, all of which enjoy forward secrecy and resilience to ephemeral key-leakage under the gap Bilinear Diffie-Hellman assumption in the random oracle model. © 2012 Springer-Verlag

    ID-based Authenticated Two Round Multi-Party Key Agreement

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    This paper proposes an ID-based authenticated two round multi-party key agreement among n parties. Several ID-based two-party and tripartite key agreement schemes were proposed recently. Our two round multi-party key agreement scheme utilizes the idea of the two-round group key exchange protocol of Burmester and Desmedt. The authenticity of the protocol is assured by a special signature scheme, so the messages carrying the information of ephemeral key can be broadcasted authentically by an entity. Security attributes of our protocol are presented, and computational overhead and band width of the broadcast messages are analyzed as well

    Group key establishment protocols: Pairing cryptography and verifiable secret sharing scheme

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    Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 2013Includes bibliographical references (leaves: 97-103)Text in English; Abstract: Turkish and Englishx, 154 leavesThe aim of this study is to establish a common secret key over an open network for a group of user to be used then symmetrical secure communication between them. There are two methods of GKE protocol which are key agreement and key distribution. Key agreement is a mechanism whereby the parties jointly establish a common secret. As to key distribution, it is a mechanism whereby one of the parties creates or obtains a secret value and then securely distributes it to other parties. In this study, both methods is applied and analyzed in two different GKE protocols. Desirable properties of a GKE are security and efficiency. Security is attributed in terms of preventing attacks against passive and active adversary. Efficiency is quantified in terms of computation, communication and round complexity. When constructing a GKE, the challenge is to provide security and efficiency according to attributed and quantified terms. Two main cryptographic tools are selected in order to handle the defined challenge. One of them is bilinear pairing which is based on elliptic curve cryptography and another is verifiable secret sharing which is based on multiparty computation. In this thesis, constructions of these two GKE protocols are studied along with their communication models, security and efficiency analysis. Also, an implementation of four-user group size is developed utilizing PBC, GMP and OpenSSL Libraries for both two protocols

    Security analysis on Nalla-Reddy\u27s ID-based tripartite authenticated key agreement protocols

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    In this paper we propose security analysis on passive attack for Nalla-Reddy\u27s ID-AK-2 and ID-AK-3 protocols
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