• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.387-390
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• 2009

Digital devices that apply Ubiquitous-IT Convergence in ship manufacture are used as ship automation device. Need sailing data recording of ship black box that equip integrity and consecutiveness as legal confesser fare that inquire responsibility whereabouts of disaster such as fire of ship. It is research that create Forensic data from ship black box using Multidimensional networking that use ZigBee radio short distance communications division Wireless LAN with short distance RFID sensor that is used in ship in this treatise, UWB communication, GPS and artificial satellite. Sailing recording of shipping that is recorded to black box is transmited, and stores doubly by real time on ship insurance company and ship administration recording membrane using SHA-1 hash function and secure consecutiveness and integrity as Forensic data through artificial satellite encoding by 3DES 1024bit.

• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.155-164
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• 2006

VoIP technology is Eight New Services among Ubiquitous-IT839 strategies. This paper tested wiretapping or VoIP service in connected a soft phone and LAN and WAN sections, Internet telephones and a device. IP PBX, a banner operator network to have been connected to VoIP Internet network. As a result of having experimented on wiretapping of VoIP networks, Vulnerability was found. and a wiretapping by attacks of a hacker was succeeded in a terminal and proxy and attachment points of a VoIP network like a hub to follow a CVE list. Currently applied a security plan of an each wiretapping section in viewpoints of 6 security function of Access Control. Confidentiality, Authentication. Availability, Integrity. Non-repudiation in VoIP networks named to 070. Prevented wiretapping of contents by the results, the AES encryption that executed wiretapping experiment about a packet after application of a security plan. Prevented wiretapping, and kept security and audit log. and were able to accomplish VoIP information protection to network monitoring and audit log by an access interception and qualification and message hash functions and use of an incoming refusal.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.3
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• pp.115-126
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• 2005

SHACAL-2 is a 256-bit block cipher with up to 512 bits of key length based on the hash function SHA-2. It was submitted to the the NESSIE project and was recommended as one of the NESSIE selections. In this paper, we present two types of related-key attacks called the related-key differential-(non)linear and the related-key rectangle attacks, and we discuss the security of SHACAL-2 against these two types of attacks. Using the related-key differential-nonlinear attack, we can break SHACAL-2 with 512-bit keys up to 35 out of its 64 rounds, and using the related-key rectangle attack, we can break SHACAL-2 with 512-bit keys up to 37 rounds.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.85-96
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• 2008

Neighbor Discovery(ND) protocol is used to exchange an information of the neighboring nodes on the same link in the IPv6 protocol environment. For protecting the ND protocol, firstly utilizing Authentication Header(AH) of the IPsec protocol was proposed. But the method has some problems-uses of key exchange protocol is not available and it is hard to distribute manual keys. And then secondly the SEcure Neighbor Discovery(SEND) protocol which protects all of the ND message with digital signature was proposed. However, the digital signature technology on the basis of public key cryptography system is commonly known as requiring high cost, therefore it is expected that there is performance degradation in terms of the availability. In the paper, to improve performance of the SEND protocol, we proposed a modified CGA(Cryptographically Generated Address) which is made by additionally adding MAC(Media Access Control) address to the input of the hash function. Also, we proposed cache mechanism. We compared performance of the methods by experimentation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.2
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• pp.105-115
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• 2009

At the most recent, IPTV service is increasing, which isa communicative broadcasting fusion service that provides various multimedia contents interactively followed by user's request through super high-speed internet. For IPTV user service with high mobility, IPTV user's enrollment is essential. However, IPTV service provided to mobile users can't provide the certification of mobile user securely. This paper proposes light user certification protocol which can certificate mobile users by attaching RFID to IPTV STB for secure awareness of mobile users who get IPTV service. The proposed protocol prevent reply attack and man-in-the-middle attack from happening oftenin a wireless section by transmitting the result value hashed by hash function with both its' ID and random number received from tag after tag transmits random number which generated randomly in the process of certification of mobile user to IPTV STB.

• 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.6
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• pp.25-35
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• 2006

Radio Frequency identification (RFID) will become an important technology in remotely object identification systems. However, the use of RFID tags may create new threats to the sniな and Privacy of individuals holding RFID tags. These threats bring several problems which are information leakage of a tag, location trace of individuals and impersonation of a tag. Low-cost RFID systems have much restrictions such as the limited computing power, passive power mechanism and low storage space. Therefore, the cost of tag's computation should be considered as an important factor in low-cost RFID systems. We propose an authentication protocol, OHLCAP which requires only one one-way hash function operation and hence is very efficient. Furthermore, our protocol is suitable to distribution database environment. Hence our scheme can be applied to ubiquitous computing environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.3
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• pp.463-472
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• 2012

This paper propose a security method that performs mutual authentication between the SIP UA and the server, check for integrity of the signaling channel and protection of SDP information for VoIP using a One-Time Password. To solve the vulnerability of existing HTTP Digest authentication scheme in SIP, Various SIP Authentication schemes have been proposed. But, these schemes can't meet security requirements of SIP or require expensive cryptographic operations. Proposed method uses OTP that only uses hash function and is updated each authentication. So Proposed method do not require expensive cryptographic operations but performs user authentication efficiently and safely than existing methods. In addition, Proposed method verifies the integrity of the SIP messages and performs SDP encryption/decryption through OTP that used for user authentication. So Proposed method can reduce communication overhead when applying S/MIME or TLS.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.3
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• pp.405-415
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• 2012

In many applications a reader needs to determine whether a particular tag exists within a group of tags without a server. This is referred to as serverless RFID tag searching. A few protocols for the serverless RFID searching are proposed but they are the single tag search protocol which can search a tag at one time. In this paper, we propose a multi-tag search protocol based on a hash function and a random number generator which can search some tags at one time. For this study, we introduce a protocol which can resolve the problem of synchronization of seeds when communication error occurs in the S3PR protocol[1], and propose a multi-tag search protocol which can reduce the communication overhead. The proposed protocol is secure against tracking attack, impersonation attack, replay attack and denial-of-service attack. This study will be the basis of research for multi-tag serach protocol.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.3
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• pp.9-21
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• 2010

Recently, famous online shopping websites were hit by hacking attack, and many users' personal information such as ID, password, account number, personal number, credit card number etc. were compromised. Hackers are continuing to attack online shopping websites, and the number of victims of these hacking is increasing. Especially, the exposure of credit card numbers is dangerous, because hackers maliciously use disclosed card numbers to gain money. In 2007 Financial Cryptography Conference, Ian Molly et al. firstly proposed dynamic card number generator, but it doesn't meet reuse resistant. In this paper, we analyzed security weaknesses of Ian Molly's scheme, and we proposed a new one-time virtual card number generator using a mobile device which meets security requirements of one-time virtual card numbers. Then, we propose one-time credit card number generation and transaction protocol using Integrated Authentication Center for user convenience and security enhancement.