• Proceedings of the Korean Society of Computer Information Conference
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• 2012.07a
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• pp.203-206
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• 2012

The System of communication with wireless devices is experiencing a huge growth. While traditional communication paradigms deal with fixed networks, mobility raises a new set of questions, techniques, and solutions. In order to realize service mobility, there is a need of protocol that can support mobility while nodes are communicating without any disruption of their connection status. This paper proposes a handover authentication protocol for mobility support. Careful considerations must be taken in priority to security issues since many unreliable public and private resources; both networks and devices are involved. The protocol is based on public key cryptography with Diffie-Hellman algorithm which provides security against both leakage-resilience of private keys on untrustworthy devices and forward secrecy.

• Current Optics and Photonics
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• v.3 no.2
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• pp.119-127
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• 2019

A new secret-key-sharing cryptosystem using optical phase-shifting digital holography is proposed. The proposed secret-key-sharing algorithm is based on the Diffie-Hellman key-exchange protocol, which is modified to an optical cipher system implemented by a two-step quadrature phase-shifting digital holographic encryption method using orthogonal polarization. Two unknown users' private keys are encrypted by two-step phase-shifting digital holography and are changed into three digital-hologram ciphers, which are stored by computer and are opened to a public communication network for secret-key-sharing. Two-step phase-shifting digital holograms are acquired by applying a phase step of 0 or ${\pi}/2$ in the reference beam's path. The encrypted digital hologram in the optical setup is a Fourier-transform hologram, and is recorded on CCDs with 256 quantized gray-level intensities. The digital hologram shows an analog-type noise-like randomized cipher with a two-dimensional array, which has a stronger security level than conventional electronic cryptography, due to the complexity of optical encryption, and protects against the possibility of a replay attack. Decryption with three encrypted digital holograms generates the same shared secret key for each user. Schematically, the proposed optical configuration has the advantage of producing a kind of double-key encryption, which can enhance security strength compared to the conventional Diffie-Hellman key-exchange protocol. Another advantage of the proposed secret-key-sharing cryptosystem is that it is free to change each user's private key in generating the public keys at any time. The proposed method is very effective cryptography when applied to a secret-key-exchange cryptosystem with high security strength.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1609-1617
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• 2019

Described in this paper is a design of hardware accelerator for implementing public-key cryptographic protocols (PKCPs) based on Elliptic Curve Cryptography (ECC) and RSA. It supports five elliptic curves (ECs) over GF(p) and three key lengths of RSA that are defined by NIST standard. It was designed to support four point operations over ECs and six modular arithmetic operations, making it suitable for hardware implementation of ECC- and RSA-based PKCPs. In order to achieve small-area implementation, a finite field arithmetic circuit was designed with 32-bit data-path, and it adopted word-based Montgomery multiplication algorithm, the Jacobian coordinate system for EC point operations, and the Fermat's little theorem for modular multiplicative inverse. The hardware operation was verified with FPGA device by implementing EC-DH key exchange protocol and RSA operations. It occupied 20,800 gate equivalents and 28 kbits of RAM at 50 MHz clock frequency with 180-nm CMOS cell library, and 1,503 slices and 2 BRAMs in Virtex-5 FPGA device.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.12
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• pp.3352-3365
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• 2012

Group key agreement (GKA) is a cryptographic primitive allowing two or more users to negotiate a shared session key over public networks. Wu et al. recently introduced the concept of asymmetric GKA that allows a group of users to negotiate a common public key, while each user only needs to hold his/her respective private key. However, Wu et al.'s protocol can not resist active attacks, such as fabrication. To solve this problem, Zhang et al. proposed an authenticated asymmetric GKA protocol, where each user is authenticated during the negotiation process, so it can resist active attacks. Whereas, Zhang et al.'s protocol needs a partially trusted certificate authority to issue certificates, which brings a heavy certificate management burden. To eliminate such cost, Zhang et al. constructed another protocol in identity-based setting. Unfortunately, it suffers from the so-called key escrow problem. In this paper, we propose the certificateless authenticated asymmetric group key agreement protocol which does not have certificate management burden and key escrow problem. Besides, our protocol achieves known-key security, unknown key-share security, key-compromise impersonation security, and key control security. Our simulation based on the pairing-based cryptography (PBC) library shows that this protocol is efficient and practical.

• Journal of the Korea Safety Management & Science
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• v.9 no.3
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• pp.103-109
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• 2007

Payment and security requirement are playing an increasingly critical role in RFID system, allegedly the core of the ubiquitous, especially in logistics. Therefore, security technology has been playing essential role gradually unlike the past when only the perception of equipment was considered important technology. The current encoding system allows the access only to the user who has the secret key. Many encoding algorithm has been studied to ensure the security of secret key. Security protocol is the most typical way to authorize appropriate user perception by using the data and secret key to proceed the encoding and transmit it to the system in order to confirm the user. However, RFID system which transmits more than dozens of data per second cannot be used if the algorithm and protocol of the existing wired system are used because the performance will degrade as a consequence. Security protocol needs to be designed in consideration of property of RFID and hardware. In this paper, a protocol was designed using SNEP(Sensor Network Encryption Protocol), the security protocol used for the sensor similar to RFID- not the current system used in wired environment- and ECC (Elliptic Curve Cryptography: oval curve encoding), the encoding algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1393-1401
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• 2013

What is RFID Microchip tag attached to an object, the reader recognizes technology collectively, through communication with the server to authenticate the object. A variety of RFID tags, 13.56Mhz bandwidth RFID card, ISO/IEC 14443 standards based on NXP's Mifare tag occupies 72.5% of the world market. Of the Mifare tags, low cost tag Mifare Classic tag provided in accordance with the limited hardware-based security operations, protocol leaked by a variety of attacks and key recovery vulnerability exists. Therefore, in this paper, Cryptography Scheme and Secure Protocol for Safety Secure Scheme Construction in 13.56Mhz RFID have been designed. The proposed security scheme that KS generated by various fixed values and non-fixed value, S-Box operated, values crossed between LFSR and S-Box is fully satisfied spoofing, replay attacks, such as vulnerability of existing security and general RFID secure requirement. Also, It is designed by considering the limited hardware computational capabilities and existing security schemes, so it could be suit to Mifare Classic now.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.9
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• pp.494-503
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• 2003

In this paper, we propose the implementation techniques of IC card chipset that is compatible with international standard ISO-7816 and supports WindowsCE operating system to expropriate various electronic cash and credit card. This IC card interface chip set is composed with 32 bit ARM720T Core and AES(Advanced Encryption System) cryptography module for electronic commerce. Six IC card interfaces support T=0, T=1 protocol and two of them are used to interface with user card directly, the others are used for interface with SAM card. In addition, It supports a LCD controller and USB interface for host. We improved the performance about 70% than software based It card chip set and verified using Hynix 0.35um process.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.586-594
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• 2014

Maximizing the operating time by reducing the power consumption is important factor to operate sensor network under water networks. For efficient power consumption, dynamic voltage scaling method is available. This method operates low frequency when there is no workload. In case of abundant workload, high frequency operation completes hard work within short time, reducing power consumption. For this reason, complex cryptography should be computed in high frequency. In this paper, we apply dynamic voltage scaling method to cryptography and show performance evaluation. With this result, we can reduce power consumption for cryptography in under water communication.

• 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.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.209-213
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• 2022

Key exchange protocol (KEP) is an essential setup to secure authenticates transmission among two or more users in cyberspace. Digital files protected and transmitted by the encryption of the files over public channels, a single key communal concerning the channel parties and utilized for both to encrypt the files as well as decrypt the files. If entirely done, this impedes unauthorized third parties from imposing a key optimal on the authorized parties. In this article, we have suggested a new KEP term as isokey interchange protocol based on generalization of modern mathematics term as isomathematics by utilizing isonumbers for corresponding isounits over the Block Upper Triangular Isomatrices (BUTI) which is secure, feasible and extensible. We also were utilizing arithmetic operations like Isoaddition, isosubtraction, isomultiplication and isodivision from isomathematics to build iso-key interchange protocol for network communication. The execution of our protocol is for two isointegers corresponding two elements of the group of isomatrices and cryptographic performance of products eachother. We demonstrate the protection of suggested isokey interchange protocol against Brute force attacks, Menezes et al. algorithm and Climent et al. algorithm.