• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.6
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• pp.71-80
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• 2002

To provide the confidentiality of messages transmitted over the network, the use of cryptographic system is increasing gradually and the hybrid cryptosystem, which combines the advantages of the symmetric cryptosystem and the public key cryptosystem is widely used. In this paper, we proposes a new hybrid cryptosystem capable of providing implicit authentication for the sender of the ciphertext by means of the 1-pass key distribution protocol that offers implicit key authentication, hash function and symmetric cryptosystem. Also, we describe some examples such as the Diffie-Hellman based system and the Nyberg-Ruppel based system. The proposed hybrid cryptosystem is an efficient more than general public key cryptosystems in the aspect of computation work and provides implicit authentication for the sender without additional increase of the communication overhead.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.4
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• pp.127-138
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• 2006

The IPSec is a basic security mechanism of the IPv6 protocol, which can guarantee an integrity and confidentiality of data that transmit between two corresponding hosts. Also, both data and communication subjects can be authenticated using the IPSec mechanism. However, it is difficult that the IPSec mechanism protects major important network from attacks which transmit mass abnormal IPSec traffic in session-configuration or communication phases. In this paper, we present a design of the security system that can effectively detect and defeat abnormal IPSec traffic, which is encrypted by the ESP extension header, using the IPSec Session and Configuration table without any decryption. This security system is closely based on a multi-tier attack mitigation mechanism which is based on network bandwidth management and aims to counteract DDoS attacks and DoS effects of worm activity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.4
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• pp.13-26
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• 2006

RFID technology is evaluated as one of core technologies for ubiquitous environment, because of its various characteristics which barcode systems don't have. However, RFID systems have consumer's privacy infringement problems, such like information leakage and location tracing. We need RFID privacy protection protocols, that satisfy three essential security requirements; confidentiality, indistinguishability and forward security, in order to protect consumer's privacy perfectly. The most secure protocol, that satisfies all of the three essential security requirements, among existing protocols, is the hash-chain based protocol that Ohkubo proposed. Unfortunately this protocol has a big disadvantage that it takes very long time to identify a tag in the back-end server. In this paper, we propose a scheme to keep security just as it is and to reduce computation time for identifying a tag in back-end server. The proposed scheme shows the results that the identification time in back-end server is reduced considerably compared to the original scheme of Ohkubo protocol.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.5
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• pp.47-57
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• 2006

Mobile Ad-hoc networks have various implementation constraints such as infrastructure-free, no trusted authority, node mobility, and the limited power and small memory of mobile device. And just like wired networks, various security issues such as authentication, confidentiality, integrity, non-repudiation, access control, availability and so on have been arisen in mobile Ad-hoc networks. But we focus on authentication of these security issues because it is quitely affected by the characteristics of networks. In this paper, we propose the authentication protocol that can limit the size of certificate repository as $log_2N$ and assures to make a trusted certificate path from one node to another, adopting the concept of Hamming distance. Particularly, our protocol can construct a trusted certificate path in spite of decreasing or increasing the number of nodes in mobile Ad-hoc network.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.5
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• pp.47-58
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• 2011

Recently, there are several technologies for protecting information in the lightweight device, One of them, the AES[1] algorithm and CRT mode, is used for numerous services(e,g, OMA DRM, VoIP, IPTV) as encryption technique for preserving confidentiality. Although it is possible that the AES algorithm CRT mode can parallel process transmitting data, IPTV Set-top Box or Mobile Device that uses these streaming service has limited computation-ability. So optimizing crypto algorithm and enhancing its efficiency for those environment have become an important issue. In this paper, we propose implementation method that can improve efficiency of the AES-CRT Mode by improving algorithm logics. Moreover, we prove the performance of our proposal on the mobile device which has limited capability.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.5
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• pp.1057-1068
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• 2012

According to advance on vehicle technology, many kinds of ECU(Electronic Control Unit) are equipped inside the vehicle. In-vehicle communication among ECUs is performed through CAN(Controller Area Networks). CAN have high reliability. However, it has many vulnerabilities because there is not any security mechanism for CAN. Recently, many papers proposed attacks of in-vehicle communication by using these vulnerabilities. In this paper, we propose an wireless attack model using a mobile radio communication network. We propose a secure authentication mechanism for in-vehicle network communication that assure confidentiality and integrity of data packets and also protect in-vehicle communication from the replay attack.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.145-154
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• 2010

End-to-End(E2E) encryption is to encrypt private and important financial information such as user's secret access numbers and account numbers from user's terminal to financial institutions. There has been found significant security vulnerabilities by various hacking in early E2E encryption system since early E2E encryption is not satisfied the basic security requirement which is that there does not exist user's financial information on plaintext in user's terminal. Extensional E2E encryption which is to improve early E2E encryption provides confidentiality and integrity to protect user's financial information from vulnerabilities such as alteration, forgery and leakage of confidential information. In this paper, we explain the extensional E2E encryption technology and present considerable security issues when the extensional E2E encryption technology is applied to financial systems.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.981-997
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• 2020

Blockchain technology can provide a high level security based on a decentralized distributed ledger and consensus-based structure. In order to increase the utilization of blockchain technology, it is necessary to find a way to use it in fields that require personal data processing such as health care and e-commerce. To achieve this goal, the blockchain based system should be able to comply with data privacy regulations represented by European Union(EU)'s GDPR(General Data Protection Regulation). However, because of the properties of the blockchain like the immutability and decentralized recorded data, it is difficult to technically implement the requirements of the existing privacy regulations on the blockchain. In this paper, we propose a multi-chain based access control system that can guarantee the rights of the personal data subject required by GDPR by utilizing Chameleon Hash and Attribute Based Encryption (ABE). Finally, we will show through security analysis that our system can handle personal data while maintaining confidentiality and integrity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.1247-1254
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• 2020

With the advent of the smart home era, equipment that provides confidentiality or performs authentication exists in various places in real life. Accordingly security against physical attacks is required for encryption equipment and authentication equipment. In particular, fault injection attack that artificially inject a fault from the outside to recover a secret key or bypass an authentication process is one of the very threatening attack methods. Fault sources used in fault injection attacks include lasers, electromagnetic, voltage glitches, and clock glitches. Fault injection attacks are classified into single fault injection attacks and multiple fault injection attacks according to the number of faults injected. Existing multiple fault injection systems generally use a single fault source. The system configured to inject a single source of fault multiple times has disadvantages that there is a physical delay time and additional equipment is required. In this paper, we propose a multiple fault injection system using heterogeneous fault sources. In addition, to show the effectiveness of the proposed system, the results of a multiple fault injection attack against Riscure's Piñata board are shown.

• Convergence Security Journal
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• v.20 no.4
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• pp.47-59
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• 2020

The Army, which is dreaming of a military leap forward through the fourth industrial revolution, needs to also consider the side effects and adverse functions of the fourth industrial revolution. In particular, this study conducted an analysis of whether it was consistent with the global technological trend of normal 'military security'. This paper focuses on the countermeasures that could result from 4th industrial revolution by utilizing the text-mining technique and social network technique of big data. 1. Active promotion of a convergence program with private, public, militaryand industrial, academic, and solidarity, 2. Information Sharing for International Cooperation and Cooperation in Cyber security, 3. Military Innovation and Military Unsymmetric Cyber security innovation, 4.The Establishment of Military Security Convergence Interface Management System in accordance with the Fourth Industrial Revolution, 5. Cooperation in the transition from technology engineering to social technology, 6. Establishing a military security governance system in the military, 7. Specifying confidential military digital data We look forward to providing useful information so that the results of this study can help develop the military and enhance military confidentiality.