Tree-based Group Diffie-Hellman Research Articles

A Novel Cryptographic method for Securing Active Conventions in Data Networks

Dynamic conferencing alludes to a situation where in any subset of clients in a vast expanse of clients structure a convention for dividing secret data between them. The key dissemination (KD) issue in powerful conferencing is to register a common secret key for such a progressively framed meeting. In writing, the KD plans for active conventions either are computationally unscalable or require correspondence among clients, which is unfortunate. The extensive symmetric polynomial based dynamic conferencing system (ESPDCS) is one such KD conspires which has a high computational intricacy that is universe size subordinate. In this paper we present upgrades to the ESPDCS to foster a KD conspire called Universe-Free SPDCS (UF-SPDCS) with the end goal that its intricacy is autonomous of the universe size. In any case, the UF-SPDCS conspire doesn't scale with the convention size. We propose a moderately versatile KD conspire named as DH-SPDCS that utilizes the UF-SPDCS and the tree-based group Diffie-Hellman (TGDH) key exchange procedure. The proposed DH-SPDCS gives a configurable compromise among calculation and correspondence intricacy of the plan.

TBAC: tree-based access control approach for secure access of PHR in cloud

Personal Health Record (PHR) system is a currently emerging patient-oriented model for sharing the health information through a cloud environment. Previously, single attribute authority-based security scheme was used for sharing the PHRs in the cloud. But, this security scheme is not practically applicable due to the security and privacy issues. The existing access control approaches require more time to encrypt and decrypt the PHR file. This paper proposes a Tree-Based Access Control (TBAC) approach for fine-grained and secure access of the PHR in the cloud environment. In our approach, Tree-based Group Diffie-Hellman (TBGDH) algorithm is used to generate the key instance for the encryption process. The Attribute-based Encryption (ABE) approach is used with different hierarchical levels of the users to protect the personal health data. The access policies are based on the user attribute.

TBAC: Tree-Based Access Control Approach for Secure Access of PHR in Cloud

Personal Health Record (PHR) system is a currently emerging patient-oriented model for sharing the health information through a cloud environment. Previously, single attribute authority-based security scheme was used for sharing the PHRs in the cloud. But, this security scheme is not practically applicable due to the security and privacy issues. The existing access control approaches require more time to encrypt and decrypt the PHR file. This paper proposes a Tree-Based Access Control (TBAC) approach for fine-grained and secure access of the PHR in the cloud environment. In our approach, Tree-based Group Diffie-Hellman (TBGDH) algorithm is used to generate the key instance for the encryption process. The Attribute-based Encryption (ABE) approach is used with different hierarchical levels of the users to protect the personal health data. The access policies are based on the user attribute.

Re-Ordering of Users in the Group Key Generation Tree Protocol

Abstract Tree-based Group Diffie-Hellman (TGDH) is one of the efficient group key agreement protocols to generate the GK. TGDH assumes all members have an equal computing power. As one of the characteristics of distributed computing is heterogeneity, the member can be at a workstation, a laptop or even a mobile computer. Therefore, the group member sequence should be reordered in terms of the member’s computing power to improve performance. This research proposes a reordering of members in the group key generation tree to enhance the efficiency of the group key generation. Key Words : Protocol design, network security, authentication, group communication, agreement protocols, group key management. * 소속 직책: 백석대학교 정보통신학부 조교수논문접수: 2012년 6월 27일, 1차 수정을 거쳐, 심사완료: 2012년 7월 23일 1. Introduction Android phones and iPhone are used a lot by users. More than 70% of cell phone users are smart phones which are able to communicate with other smart phone users. Group communications are pervaded over the network such as video conferences and on-line chatting programs, games, and gambling. Security plays an important role in these instances of group communication. According to [11], user authentication processes and key distribution are just at the beginning of the group communication [11]. The CGK generation, on the other hand, takes a relatively long time to complete. For achieving a high level of security, the CGK should be changed after every user joins and leaves so that a former group member has no access to current communications and a new member has no access to previous communications [11] To improve the group communication efficiency, the CGK generation needs to be optimized by the improved key generation algorithm. Accordingly, group key agreement protocol focuses on the CGK generation. The function for generating CGK in the group key agreement is a modular exponentiation. In order to calculate the CGK using modular exponentiations, the adaptation of key trees is needed to reduce the computational overhead. Modular exponentiation is the computationally most expensive operation in TGDH [2]. The number of exponentiations for membership events depends on the number of

Formal Verification of Secrecy in Group Key Protocols Using Event-B

Group key security protocols play an important role in today’s communication systems. Their verification, however, remains a great challenge because of the dynamic characteristics of group key construction and distribution protocols. Security properties that are well defined in normal two-party protocols have different meanings and different interpretations in group key distribution protocols, specifically, secrecy properties, such as group secrecy, forward secrecy, backward secrecy, and key independence. In this paper, we present a method to verify forward secrecy properties for group-oriented protocols. The method is based on a correct semantical link between group key protocols and event-B models and also uses the refinement process in the B method to model and verify group and forward secrecy. We use an event-B first-order theorem proving system to provide invariant checking for these secrecy properties. We illustrate our approach on the Tree based Group Diffie-Hellman protocol as case study.

A Secure Group Communication and Rekeying using Rabins Squaring Trapdoor Function in Multicasting

In today‟s world of internet, secure communication among group of members has become vital, where multicasting plays an important role. In secure multicasting, security and scalability are the two important checks. Sometimes there is tradeoff between security and scalability. In order to transmit the data in a secure and scalable way, a suitable key management protocol should be implemented which reduces the number of rekey messages generated during the join or leave of any member thereby preserving forward and backward secrecy. In our proposed work, a new key management protocol has been proposed where a hierarchical structure has been implemented to improve the scalability. Derivation key is used to generate the new keys from the existing keys and Rabin‟s Squaring Trapdoor Function is used as the key derivation function to distribute the rekey messages. The security of the key derivation function lies in the hard mathematical problem of integer factorization which cannot be solved in a polynomial time. In order to increase the security, a salt value has been used along with the derivation keys for key stretching so that original keys used in the derivation function cannot be found out. The proposed protocol reduces the rekey messages by 1/d, in a d-degree tree and the number of modular exponential operations is only 2h compared to 3h in TGDH (Tree-based Group Diffie-Hellman) protocol, where h is the height of the tree.

Secure and Efficient Tree-based Group Diffie-Hellman Protocol

Current group key agreement protocols (often tree-based) involve unnecessary delays because members with low-performance computer systems can join group key computation. These delays are caused by the computations needed to balance a key tree after membership changes. An alternate approach to group key generation that reduces delays is the dynamic prioritizing mechanism of filtering low performance members in group key generation. This paper presents an efficient tree-based group key agreement protocol and the results of its performance evaluation. The proposed approach to filtering of low performance members in group key generation is scalable and it requires less computational overhead than conventional tree-based protocols.

A Decentralized Group Key Management Scheme for the Decentralized P2P Environment

In this letter, we propose a decentralized group key management algorithm called DECLKH, which combines the logical key hierarchy (LKH) and the tree-based group Diffie- Hellman (TGDH) schemes. LKH is a centralized key distribution scheme, and thus, lacks fault-tolerance. On the other hand, TGDH is relatively inferior in terms of performance to LKH although it is fault-tolerant. The proposed algorithm, <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DECLKH</i> , solves the single point of failure problems of LKH with much more enhanced performance than TGDH.

Tree-based group key agreement

Secure and reliable group communication is an active area of research. Its popularity is fueled by the growing importance of group-oriented and collaborative applications. The central research challenge is secure and efficient group key management. While centralized methods are often appropriate for key distribution in large multicast-style groups, many collaborative group settings require distributed key agreement techniques. This work investigates a novel group key agreement approach which blends key trees with Diffie--Hellman key exchange. It yields a secure protocol suite called Tree-based Group Diffie--Hellman (TGDH) that is both simple and fault-tolerant. Moreover, the efficiency of TGDH appreciably surpasses that of prior art.