• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.4
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• pp.971-980
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• 2017

Data deduplication can be utilized to reduce storage space in cloud storage services by storing only a single copy of data rather than all duplicated copies. Users who are concerned the confidentiality of their outsourced data can use secure encryption algorithms, but it makes data deduplication ineffective. In order to reconcile data deduplication with encryption, Liu et al. proposed a new server-side cross-user deduplication scheme by exploiting password authenticated key exchange (PAKE) protocol in 2015. In this paper, we demonstrate that this scheme has side channel which causes insecurity against the confirmation-of-file (CoF), or duplicate identification attack.

• Journal of Korea Multimedia Society
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• v.8 no.4
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• pp.525-535
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• 2005

A password-based authenticated tripartite key exchange protocol based on A. Joux's protocol was proposed. By using encryption scheme with shared password, we can resolve man-in-the-middle attack and lack of authentication problems. We also suggested a scheme to avoid the offline dictionary attack to which symmetric encryption schemes are vulnerable. The proposed protocol does not require a trusted party which is required in certificate or identity based authentication schemes. Therefore in a ad hoc network which is difficult to install network infrastructure, the proposed protocol would be very useful. The proposed protocol is more efficient in computation aspect than any existing password-based authenticated tripartite key exchange protocols. When it is used as a base line protocol of tree based group key exchange protocol, the computational weak points of the proposed protocol are compensated.

• Journal of information and communication convergence engineering
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• v.15 no.4
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• pp.212-216
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• 2017

In this paper, we introduce novel techniques to improve the high performance of AE functions on modern high-end IoT platforms (ARM-NEON), which support SIMD and cryptography instruction sets. For the Sophie Germain Counter Mode of operation (SGCM), counter modes of encryption and prime field multiplication are required. We chose the Montgomery multiplication for modular multiplication. We perform Montgomery multiplication in a parallel way by exploiting both the ARM and NEON instruction sets. Specifically, the NEON instruction performed 128-bit integer multiplication and the ARM instruction performed Montgomery reduction, simultaneously. This approach hides the latency for ARM in the NEON instruction set. For a high-speed counter mode of encryptions for both AE functions, we introduced two-level computations. When the tasks were large volume, we switched to the NEON instruction to execute the encryption operations. Otherwise, we performed the encryptions on the ARM module.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.6
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• pp.1319-1326
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• 2019

Recently, biometrics and location information are being used for authentication in many devices. However, these information are stored as plaintext in safe device or, stored as ciphertext in authentication server it is used for authentication in plaintext by decrypting. Therefore, the leakage of authentication information as well as hacking can cause fatal privacy problems. In this paper, we propose a technique that can be authenticated without exposing authentication information to ciphertext using function encryption.

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.204-210
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• 2019

Mobile Crowd Computing is one of the most efficient and effective way to collect the Electronic health records and they are very intelligent in processing them. Mobile Crowd Computing can handle, analyze and process the huge volumes of Electronic Health Records (EHR) from the high-performance Cloud Environment. Electronic Health Records are very sensitive, so they need to be secured, authenticated and processed efficiently. However, security, privacy and authentication of Electronic health records(EHR) and Patient health records(PHR) in the Mobile Crowd Computing Environment have become a critical issue that restricts many healthcare services from using Crowd Computing services .Our proposed Efficient Multi-layer Encryption Framework(MLEF) applies a set of multiple security Algorithms to provide access control over integrity, confidentiality, privacy and authentication with cost efficient to the Electronic health records(HER)and Patient health records(PHR). Our system provides the efficient way to create an environment that is capable of capturing, storing, searching, sharing, analyzing and authenticating electronic healthcare records efficiently to provide right intervention to the right patient at the right time in the Mobile Crowd Computing Environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7C
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• pp.1007-1014
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• 2004

In this paper, H.235 based security mechanism for H.323 multimedia applications was implemented in embedded environment. H.235 covers authentication using HMAC-SHAI -96, authenticated Diffie-Hellman key exchange, security capability exchange, session key management for voice encryption, and encryption functions such as DES, 3DES, RC2. H.235-based mechanisms were also analyzed in terms of its security and possible attacks.

• Journal of the Korea Society of Computer and Information
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• v.3 no.4
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• pp.91-96
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• 1998

In this paper we designed a secure client-server system to be able to protect messages between client and server using cryptography We authenticated each other using a asymmetric encryption algorithm on the logon procedure and minimized the time to encrypt and decrypt messages using a symmetric encryption algorithm on exchanging messages. We proved that it is possible to make a digital signature on our secure client-server system. And we suggested the efficient key management method to generate and distribute cryptograpic key securely.

• Journal of information and communication convergence engineering
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• v.8 no.2
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• pp.129-135
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• 2010

Wireless sensor networks (WSNs) are an emerging technology and offers economically viable monitoring solution to many challenging applications. However, deploying new technology in hostile environment, without considering security in mind has often proved to be unreasonably unsecured. Apparently, security techniques face many critical challenges in WSNs like data security and secrecy due to its hostile deployment nature. In order to resolve security in WSNs, we propose a novel and efficient secure framework called TriSec: a secure data framework for wireless sensor networks to attain high level of security. TriSec provides data confidentiality, authentication and data integrity to sensor networks. TriSec supports node-to-node encryption using PingPong-128 stream cipher based-privacy. A new PingPong-MAC (PP-MAC) is incorporated with PingPong stream cipher to make TriSec framework more secure. PingPong-128 is fast keystream generation and it is very suitable for sensor network environment. We have implemented the proposed scheme on wireless sensor platform and our result shows their feasibility.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1240-1243
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• 2003

In this paper, an encryption method to share a secret binary image is proposed. It divides the image to be encrypted into an arbitrary number of images and encrypts them using XOR process with different binary random images which was prepared by the means of the XOR process, too. Each encrypted slice image can be distributed to the authenticated ones. However, we transfer the encrypted images to the binary phase masks to strengthen the security power, that means phase masks can not be copied with general light-intensity sensitive tools such as CCDs or cameras. For decryption, we used the Mach-Zehnder interferometer in which linearly polarized two light beams in orthogonal direction, respectively. The experimental result proved the efficiency of the proposed method.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.497-500
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• 2006

신상욱 등은 JCCI 2003에서 새로운 인증-암호화 모드 NAE를 제안하였다. NAE는 CFB 모드와 CTR 모드를 결합시킨 변형된 형태로, 하나의 기반이 되는 블록 암호 키를 가지고 최소한으로 블록 암호를 호출하여 기밀성과 무결성을 모두 제공한다. 이 모드는 CBC 암호화 모드와 CBC-MAC이 결합된 CCM 인증-암호화 모드보다 효율적이며, 기제안된 다른 인증-암호화 기법들과 유사한 성능을 가진다. 그러나 본 논문에서는 단순 암호문 조작으로 유효한 암호문-태그 쌍을 생성할 수 있음을 보인다.