• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.1
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• pp.8-14
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• 2003

In this paper, we investigate a rekey mechanism for a secure multicast group communications and relate the mechanism to the loss of information from group key exposal. We also combine cost for the information loss and cost for group key updates and analyze the optimum rekey interval. Using the results of the analysis in this paper, we can manage a secure multicast group efficiently with the minimal cost on the bases of number of group members, each member's security level and withdrawal rates.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1315-1329
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• 2018

Ciphertext-policy attribute-based encryption (CP-ABE) associates ciphertext with access policies. Only when the user's attributes satisfy the ciphertext's policy, they can be capable to decrypt the ciphertext. Expressivity and security are the two directions for the research of CP-ABE. Most of the existing schemes only consider monotonic access structures are selectively secure, resulting in lower expressivity and lower security. Therefore, fully secure CP-ABE schemes with non-monotonic access structure are desired. In the existing fully secure non-monotonic access structure CP-ABE schemes, the attributes that are set is bounded and a one-use constraint is required by these projects on attributes, and efficiency will be lost. In this paper, to overcome the flaw referred to above, we propose a new fully secure non-monotonic access structure CP-ABE. Our proposition enforces no constraints on the scale of the attributes that are set and permits attributes' unrestricted utilization. Furthermore, the scheme's public parameters are composed of a constant number of group elements. We further compare the performance of our scheme with former non-monotonic access structure ABE schemes. It is shown that our scheme has relatively lower computation cost and stronger security.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.935-949
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• 2016

In this paper, we present a novel authenticated group key distribution scheme for large and dynamic multicast groups without employing traditional symmetric and asymmetric cryptographic operations. The security of our scheme is mainly based on the basic theories for solving linear equations. In our scheme, a large group is divided into many subgroups, where each subgroup is managed by a subgroup key manager (SGKM) and a group key generation center (GKGC) further manages all SGKMs. The group key is generated by the GKGC and then propagated to all group members through the SGKMs, such that only authorized group members can recover the group key but unauthorized users cannot. In addition, all authorized group members can verify the authenticity of group keys by a public one-way function. The analysis results show that our scheme is secure and efficient, and especially it is very appropriate for secure multicast communications in large and dynamic client-server networks.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1321-1329
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• 2017

A quantum computer, based on quantum mechanics, is a paradigm of information processing that can show remarkable possibilities of exponentially improved information processing. This paradigm can be solved in a short time by calculating factoring problem and discrete logarithm problem that are typically used in public key cryptosystems such as RSA(Rivest-Shamir-Adleman) and ECC(Elliptic Curve Cryptography). In 2013, Lei et al. proposed a secure NTRU-based key distribution protocol for quantum computing. However, Lei et al. protocol was vulnerable to man-in-the-middle attacks. In this paper, we propose a NTRU(N-the truncated polynomial ring) key distribution protocol with mutual authentication only using NTRU convolution multiplication operation in order to maintain the security for quantum computing. The proposed protocol is resistant to quantum computing attacks. It is also provided a secure key distribution from various attacks such as man-in-the middle attack and replay attack.

• Journal of Communications and Networks
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• v.12 no.6
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• pp.592-599
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• 2010

In recent years, significant improvements have been made to the techniques used for analyzing satellite communication and attacking satellite systems. In 2003, a research team at Los Alamos National Laboratory, USA, demonstrated the ease with which civilian global positioning system (GPS) spoofing attacks can be implemented. They fed fake signals to the GPS receiver so that it operates as though it were located at a position different from its actual location. Moreover, Galileo in-orbit validation element A and Compass-M1 civilian codes in all available frequency bands were decoded in 2007 and 2009. These events indicate that cryptography should be used in addition to the coding technique for secure and authenticated satellite communication. In this study, we address this issue by using an authenticated key-exchange protocol to build a secure and authenticated communication channel for satellite communication. Our protocol uses identity-based cryptography. We also prove the security of our protocol in the extended Canetti-Krawczyk model, which is the strongest security model for authenticated key-exchange protocols, under the random oracle assumption and computational Diffie-Hellman assumption. In addition, our protocol helps achieve high efficiency in both communication and computation and thus improve security in satellite communication.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2447-2455
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• 2018

Security is more important in many sensor applications. The node replication attack is a major issue on sensor networks. The replicated node can capture all node details. Node Replication attacks use its secret cryptographic key to successfully produce the networks with clone nodes and also it creates duplicate nodes to build up various attacks. The replication attacks will affect in routing, more energy consumption, packet loss, misbehavior detection, etc. In this paper, a Secure-Efficient Centralized approach is proposed for detecting a Node Replication Attacks in Wireless Sensor Networks for Static Networks. The proposed system easily detects the replication attacks in an effective manner. In this approach Secure Cluster Election is used to prevent from node replication attack and Secure Efficient Centralized Approach is used to detect if any replicated node present in the network. When comparing with the existing approach the detection ratio, energy consumption performs better.

• Journal of KIISE:Information Networking
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• v.36 no.4
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• pp.263-274
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• 2009

Decentralized group key management mechanisms offer beneficial solutions to enhance the scalability and reliability of a secure multicast framework by confining the impact of a membership change in a local area. However, many of the previous decentralized solutions reveal the plaintext to the intermediate relaying proxies, or require the key distribution center to coordinate secure group communications between subgroups. In this study, we propose a decentralized group key management scheme that features a mechanism allowing a service provider to deliver the group key to valid members in a distributed manner using the proxy cryptography. In the proposed scheme, the key distribution center is eliminated while data confidentiality of the transmitted message is provided during the message delivery process. The proposed scheme can support a secure group communication in dynamic network environments where there is no trusted central controller for the whole network and the network topology changes frequently.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1B
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• pp.1-10
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• 2003

An EPON which is going on standardization in IEEE 802.3ah, is tree topology consists of a OLT and multiple ONU using passive optical components, so this network is susceptible to variable security threats - eavesdropping, masquerading, denial of service and so on. In this paper, we design a security protocol supporting authentication and confidentiality services in MAC layer in order to prevent these security threats and to guarantee secure data exchange The designed security protocol introduce public-key based authentication and key management protocols for efficient key management, and choose Rijndael algorithm, which is recent standard of AES, to provide the confidentiality of EPON Proposed authentication and key management protocols perform authentication and public-key exchange at a time, and are secure protocols using derived common cipher key by exchanging public random number To implement the designed security protocol, we propose the procedures of authentication and public-key exchange, session key update, key recovery. This proposed protocol is verified using unknown session key, forward secrecy, unknown key-share, key-compromise impersonation.

• ETRI Journal
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• v.32 no.2
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• pp.204-213
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• 2010

In this paper, we investigate the possible security threats to downloadable conditional access system (DCAS) host devices. We then propose a DCAS secure micro (SM) and transport processor (TP) security protocol that counters identified security threats using a secure key establishment and pairing management scheme. The proposed protocol not only resists disclosed SM ID and TP ID threats and indirect connection between TA and TP threats, but also meets some desirable security attributes such as known key secrecy, perfect forward secrecy, key compromised impersonation, unknown key-share, and key control.

• The Journal of Society for e-Business Studies
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• v.7 no.1
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• pp.167-186
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• 2002

The encryption of a file on a PC before saving can maintain security of the file. However, if the key for the encrypted file is lost or damaged, the encrypted file can not be decrypted, resulting in serious economical loss to the user or the user group. In order to minimize the economical loss a secure and reliable key recovery technology is required. Presented in this paper is the development and evaluation of PKRS (PC based Key Recovery System) which supports encryption and decryption of file and recovery of the encrypted file in emergency. The encapsulating method, which attaches key recovery information to encrypted file, is applied to the PKRS. In addition, the PKRS is developed and evaluated according to the requirements of Requirements for Key Recovery Products proposed by NIST and requirements of Common Criteria 2.0 to prove the safety and reliability of the information security system. This system is applicable to a PC and can be further extended to internet or intranet environment information system where in encryption and recovery of file is possible.