• Journal of Korean Society of societal Security
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• v.1 no.1
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• pp.63-67
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• 2008

This study focuses on assessing the security ri sk or the terrorism in chemical process industries. This research modifies conventional method for assessing the terrorism risk. The risk assessment method is developed and it is implemented as software to analyze the possibility of terrorism and sabotage. This program includes five steps; asset characterization, threat assessment, vulnerability analysis, risk assessment and new countermeasures. It is a systematic, risk based approach in which risk is a function of the severity of consequences of an undesired event, the likelihood of adversary attack, and the likelihood of adversary success in causing the undesired event. The reliability of the program is verified using a dock zone case. The case dock zone includes a storage farm, a manufacturing plant, an electrical supply utility, a hydrotreater unit, many containers, and administration buildings. This study represents chemical terrorism response technology, the prevention plan, and new countermeasure to mitigate by using risk assessment methods in the chemical industry and public sector. This study suggests an effective approach to the chemical terrorism response management.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9C
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• pp.855-862
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• 2009

The path key establishment phase in the wireless sensor network is vulnerable to Byzantine attack. Huang and Hedhi proposed a Byzantine resilient multi-key establishment scheme using a systematic RS code, which has shortcomings of exposing a part of message symbols and inefficient transmission. In this paper, we propose a new Byzantine resilient multi-path key establishment scheme in which direct message symbols are not exposed to an adversary and are more efficiently transmitted the RS-encoded symbols to the destination node. In the Proposed scheme, a non-systematic RS code is used to transmit a generated indirect secret key and each encoded symbol is relayed through available paths between two sensor nodes. If enough symbols are collected at the destination node, it is possible to reconstruct the secret message through RS decoding.

• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.62-68
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• 2008

Remote user authentication scheme is a cryptographic tool which permits a server to identify a remote user. In 2007, Wang et al. pointed out that Ku's remote user authentication scheme is vulnerable to a dictionary attack by obtaining some secret information in a smart card using side channel attacks. They also proposed a remote user authentication scheme which is secure against dictionary attack. In this paper, we analyze the protocol proposed by Wang et al. In the paper, it is claimed that the protocol is secure even though some values, which is stored in a smart card, are revealed to an adversary, However, we show that their protocol is insecure if the values are disclosed to an adversary.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.5_6
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• pp.239-249
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• 2003

The secret sharing is the basic concept of the threshold cryptosystem and has an important position in the modern cryptography. At 1995, Jarecki proposed the proactive secret sharing to be a solution of existing the mobile adversary and also proposed the share renewal scheme for (k, n) threshold scheme. For n participants in the protocol, his method needs $O(n^2)$ modular exponentiation per one participant. It is very high computational cost and is not fit for the scalable cryptosystem. In this paper, we propose the efficient share renewal scheme that need only O(n) modular exponentiation per participant. And we prove our scheme is secure if less than img ${\frac{1}{2}}$ n-1 adversaries exist and they are static adversary.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.9
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• pp.3231-3249
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• 2014

Deniable encryption, introduced in 1997 by Canetti, Dwork, Naor, and Ostrovsky, guarantees that the sender or the receiver of a secret message is able to "fake" the message encrypted in a specific ciphertext in the presence of a coercing adversary, without the adversary detecting that he was not given the real message. Sender - side deniable encryption scheme is considered to be one of the classification of deniable encryption technique which defined as resilient against coercing the sender. M. H. Ibrahim presented a sender - side deniable encryption scheme which based on public key and uncertainty of Jacobi Symbol [6]. This scheme has several problems; (1) it can't be able to derive the fake message $M_f$ that belongs to a valid message set, (2) it is not secure against Quadratic Residue Problem (QRP), and (3) the decryption process is very slow because it is based dramatically on square root computation until reach the message as a Quadratic Non Residue (QNR). The first problem is solved by J. Howlader and S. Basu's scheme [7]; they presented a sender side encryption scheme that allows the sender to present a fake message $M_f$ from a valid message set, but it still suffers from the last two mentioned problems. In this paper we present a new sender-side deniable public-key encryption scheme with fast decryption by which the sender is able to lie about the encrypted message to a coercer and hence escape coercion. While the receiver is able to decrypt for the true message, the sender has the ability to open a fake message of his choice to the coercer which, when verified, gives the same ciphertext as the true message. Compared with both Ibrahim's scheme and J. Howlader and S. Basu's scheme, our scheme enjoys nice two features which solved the mentioned problems: (1) It is semantically secure against Quadratic Residue Problem; (2) It is as fast, in the decryption process, as other schemes. Finally, applying the proposed deniable encryption, we originally give a coercion resistant internet voting model without physical assumptions.

• Convergence Security Journal
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• v.18 no.3
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• pp.77-85
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• 2018

With the convergence of communications network between control system and public network, such threats like information leakage/falsification could be fully shown in control system through diverse routes. Due to the recent diversification of security issues and violation cases of new attack techniques, the security system based on the information database that simply blocks and identifies, is not good enough to cope with the new types of threat. The current control system operates its security system focusing on the outside threats to the inside, and it is insufficient to detect the security threats by insiders with　the authority of security access. Thus, this study conducted the importance analysis based on the main event log list of "Spotting the Adversary with Windows Event Log Monitoring" announced by NSA. In the results, the matter of importance of event log for the detection of insider threats to control system was understood, and the results of this study could be contributing to researches in this area.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.7 no.3
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• pp.105-116
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• 1997

Routing security is related to the confidentiality of the route taken by the data transmitted over the network. If the route is detected by the adversary, the probability is higher that the data are lost or the data can be intercepted by the adversary. Therefore, the route must be protected. To accomplish this, we select an intermediate node secretly and transmit the data using this intermediate node, instead of sending the data to the destination node using the shortest path. Furthermore, if we use a number of secret routes from the starting node to the destination node, data security is much stronger since we can transmit partial data rather than the entire data along a secret route. In this paper, the routing algorithm for multiple secret paths on MRNS(Mixed Radix Number System) Network, which requires O(1) for the time complexity where is the number of links on a node, is presented employing the HCLS(Hamiltonian Circuit Latin Square) and is analyzed in terms of entropy.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.5
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• pp.59-71
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• 2005

A RFID (Radio Frequency Identification) system receives attention as the technology which can realize the ubiquitous computing environment. However, the feature of the RFID tags may bring about new threats to the security and privacy of individuals. Recently, Juels proposed the minimalist cryptography for very low-cost RFID tags, which is secure. but only under the impractical assumption such that an adversary is allowed to eavesdrop only the pre-defined number of sessions. In this paper, we propose a scheme to protect privacy for very low-cost RFID systems. The proposed protocol uses only bit-wise operations without my costly cryptographic function such as hashing, encryption which is secure which is secure against an adversary who is allowed to eavesdrop transmitted message in every session any impractical assumption. The proposed scheme also is more efficient since our scheme requires less datas as well as few number of computations than Juels's scheme.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.133-138
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• 2009

When sensor networks are deployed in open environments, an adversary may compromise some sensor nodes and use them to inject false sensing reports. False report attack can lead to not only false alarms but also the depletion of limited energy resources in battery powered networks. The Interleaved hop-by-hop authentication (IHA) scheme detects such false reports through interleaved authentication. In IHA, when a report is forwarded to the base station, all nodes on the path must spend energies on receiving, authenticating, and transmitting it. An dversary can spend energies in nodes by using the methods as a relaying attack which uses macro. The Adversary aim to drain the finite amount of energies in sensor nodes without sending false reports to BS, the result paralyzing sensor network. In this paper, we propose a countermeasure using fuzzy logic from the Denial of Service(DoS) attack and show an efficiency of energy through the simulataion result.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.214-216
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• 2005

We consider Wireless Sensor Network Security (WSN) and focus our attention to tolerate damage caused by an adversary who has compromised deployed sensor node to modify, block, or inject packets. We adopt a probabilistic secret sharing protocol where secrets shared between two sensor nodes are not exposed to any other nodes. Adapting to WSN characteristics, we incorporate these secrets to establish new pairwise key for node to node authentication and design multipath routing to multiple base stations to defend against HELLO flood attacks. We then analytically show that our defense mechanisms against HELLO flood attack can tolerate damage caused by an intruder.