• Journal of Digital Convergence
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• v.12 no.1
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• pp.573-578
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• 2014

Recently as we enter into the world of an aging society, the U-Healthcare service is newly spotlighted. In order to secure this U-Healthcare, a development of security solution that is suitable for the U-Healthcare environment is required. But the U-Healthcare environment is difficult to apply the existing security solution with the lack of standards, a security solution with high completeness was not developed. At this point, in order to structure the safe U-Healthcare environment, a generating method of an encryption key using the body information that helps the effective key management and ensuring the confidentiality of the data is proposed.

• The KIPS Transactions:PartC
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• v.12C no.2 s.98
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• pp.183-190
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• 2005

In this thesis, first, we propose I-frame encryption techniques of video data for video data itself encryption and propose license agent that processing user's certification and decryption in client system automatically when user execute encrypted video data in system server. License agent runs user's certification, encryption and decryption of video data based on PID(Public Key Infrastructure) using shared key-pool when execute of video data. Also, compose duplex buffer control and propose real time decryption method using efficient buffer scheduling to reduce much playing delay times that happen processing decryption when execute of videoa data of high-capacity.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.4
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• pp.476-482
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• 2009

As a result from Hasse's theorem it is not always possible to share a common key between any two ECC public keys. Even though ECC algorithm is more efficient than any other Encryption's with respect to the encryption strength per bit, ECC ElGamal algorithm can not be used to distribute a common key to ECC PKI owners. Approaching mathematical ways in a practical situation, we suggest possible conditions to share a common key with ECC PKI's. Using computer experiments, we also show that these suggestions are right. In the conditions, we can distribute a common key to proper peoples with ECC ElGamal algorithm.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.944-947
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• 2002

We implemented a cryptoprocessor with a on-the-fly key scheduler which performs forward key scheduling for encryption and reverse key scheduling for decryption. This scheduler makes the fast generation of the key value and eliminates the memory for software key scheduler. The 128-bit Rijndael processor is implemented based on the proposed architecture using Verilog-HDL and targeted to Xilinx XCV1000E FPGA device. As a result, the 128-bit Rijndael operates at 38.8MHz with on-the-fly key scheduler and consumes 11 cycles for encryption and decryption resulting in a throughput of 451.5Mbps

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.55-63
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• 2016

In this paper, a new asymmetric public key cryptography based on the modified RSA algorithm is proposed by using logic-based optical processing. The proposed asymmetric public key algorithm is realized into an optical schematic, where AND, OR and XOR logic operations are implemented by using free space digital optics architecture. Schematically, the proposed optical configuration has an advantage of generating the public keys simultaneously. Another advantage is that the suggested optical setup can also be used for message encryption and decryption by simply replacing data inputs of SLMs in the optical configuration. The last merit is that the optical configuration has a 2-D array data format which can increase the key length easily. This can provide longer 2-D key length resulting in a higher security cryptosystem than the conventional 1-D key length cryptosystem. Results of numerical simulation and differential cryptanalysis are presented to verify that the proposed method shows the effectiveness in the optical asymmetric cryptographic system.

• Journal of IKEEE
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• v.25 no.1
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• pp.42-46
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• 2021

A novel key exchange cryptographic method utilizing biometric finger print as a user's private key is proposed. Each unknown users' finger print is encrypted by optical phase-shifting interferometry principle and is changed into two ciphers, which are exchanged with the other party over a public communication network for secret key sharing. The transmitted ciphers generate a complex hologram, which is used to calculate a shared secret key for each user. The proposed method provides high security when applied to a secret key sharing encryption system.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.3
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• pp.56-61
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• 2012

User authentication is a necessity to set up secure system which only an authorized user can use various resource on the Internet. Encryption is to provide data privacy. Also, searchable encryption is to provide both data privacy and efficient management of data by searching with a keyword. The public key based searchable encryption requires in advance the authentication of user's public key as well as the secure management of a publlic/private key of a user, respectively. In cloud, it is purpose to use cloud various resources by using various devices, meanwhile, it is not sufficient resource that some devices manage public/private keys and certificates and it is not easy to implement these clients. To solve this problem, we propose a password-based saerchable encryption using smart cards which are temper-resistant devices.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.11
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• pp.581-588
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• 2007

In Digital Right Management, symmetric cipher is used for content encryption to reduce encryption cost, AES, advanced encryption standard is usually used to multimedia encryption under desktop environment because of its reasonable security level and computation cost. But mobile handheld device often uses slow speed processor and operates under battery-powered environment. Therefore it requires low computation cost and low energy consumption. This paper proposes new stream cipher scheme which combines pseudo random number generator(PRNG) and dynamically generated permutations. Proposed scheme activates PRNG and generates original key streams. Then it generates extended key streams by applying permutation to original sequence. These extended key streams are XORed with plaintext and generate ciphertext. Proposed scheme reduces the usage of PRNG. Therefore this scheme is fast and consumes less energy in comparison with normal stream cipher. Especially, this scheme shows great speed up (almost 2 times) than normal stream cipher scheme in random access.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.12
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• pp.2271-2279
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• 2007

In this paper, we introduce the notion of certificate-based encryption in multi-receiver environment, which avoids the inherent key escrow problem while preserving the implicit certification in identity-based encryption. We also construct a highly efficient certificate-based encryption scheme for multi-receiver environment, which eliminates pairing computation to encrypt a message for multiple receivers. Moreover, the proposed scheme only needs one pairing computation for decrypting the ciphertext. We compare our scheme with the most efficient identity-based encryption scheme for multi-receiver environment proposed by Baek et.al.[1] in terms of the computational point of view, and show that our scheme provides better efficiency than Baek's scheme. Finally, we discuss how to properly transform our scheme into a new public key broadcast encryption scheme based on subset-cover framework.

• Journal of Advanced Navigation Technology
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• v.12 no.1
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• pp.34-45
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• 2008

Broadcast encryption schemes are applied to transmit digital informations of multimedia, software, Pay-TV etc. in public network. User acquires message or session key to use key that broadcaster transmits, broadcaster need process that generation and distribution key in these process. Also, user secession new when join efficient key renewal need. In this paper, introduce about efficient key generation and distribution, key renewal method. The temporary conference environment base structure against an each mobile device wild gap. Without the transmission possible, it follows infrequent location change and with the quality where the key information change flow. Thus, in this paper, in order to apply to the embedded computing environment and the key generation and the efficient key renewal are done when the mobile device is used of the specify space it proposes.