• Journal of information and communication convergence engineering
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• 제13권4호
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• pp.280-285
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• 2015

Double random phase encryption (DRPE) is one of the well-known optical encryption techniques, and many techniques with DRPE have been developed for information security. However, most of these techniques may not solve the fundamental security problem caused by using fixed phase masks for DRPE. Therefore, in this paper, we propose a key phase mask updating scheme for DRPE to improve its security, where a spatial light modulator (SLM) is used to implement key phase mask updating. In the proposed scheme, updated key data are obtained by using previous image data and the first phase mask used in encryption. The SLM with the updated key is used as the second phase mask for encryption. We provide a detailed description of the method of encryption and decryption for a DRPE system using the proposed key updating scheme, and simulation results are also shown to verify that the proposed key updating scheme can enhance the security of the original DRPE.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권9호
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• pp.4609-4623
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• 2017

The commercialization of LTE/SAE technologies has begun a new era in which data can be transmitted at remarkably high rates. The security of the LTE/SAE network, however, remains problematic. The forward security in LTE/SAE X2 handover key management can be threatened by key compromise and de-synchronization attacks as base station in public spaces can be compromised. This study was conducted to address the lack of forward key security in X2 handover key management in scenarios in which an adversary controls a legal base station. We developed the proposed X2 handover key management by changing the parameter in the renewing step and adding a verification step. We compare the security and performance of our proposal with other similar schemes. Our enhancement scheme ensures forward separation security accompanied by favorable signal and computation load performance.

• Journal of Internet Technology
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• 제22권6호
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• pp.1287-1297
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• 2021

Data aggregation is the significant process in which the information is gathered and combines data to decrease the amount of data transmission in the WSN. The sensor devices are susceptible to node attacks and security issues such as data confidentiality and data privacy are extremely important. A novel technique called Ruzicka Index Regressive Homomorphic Ephemeral Key Benaloh Cryptography (RIRHEKBC) technique is introduced for enhancing the security of data aggregation and data privacy in WSN. By applying the Ruzicka Index Regressive Homomorphic Ephemeral Key Benaloh Cryptography, Ephemeral private and public keys are generated for each sensor node in the network. After the key generation, the sender node performs the encryption using the receiver public key and sends it to the data aggregator. After receiving the encrypted data, the receiver node uses the private key for decrypting the ciphertext. The key matching is performed during the data decryption using Ruzicka Indexive regression function. Once the key is matched, then the receiver collects the original data with higher security. The simulation result proves that the proposed RIRHEKBC technique increases the security of data aggregation and minimizes the packet drop, and delay than the state-of-the- art methods.

• 정보보호학회논문지
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• 제25권3호
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• pp.531-546
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• 2015

비대화형 키 교환 프로토콜은 키 교환을 위한 별도의 통신을 없애 시스템 내 효율성을 높일 수 있는 키 교환 프로토콜이다. 그러나 개인키 업데이트를 하지 않는 일반적인 비대화형 키 교환 프로토콜은 임시키를 사용하지 않기 때문에 전방향 안전성(forward secrecy)을 만족하지 못한다. 2012년 Sang 등은 인증서를 사용하지 않는 공개키 기반의 비대화형 키 교환(CL-NIKE : Certificateless Non-Interactive Key Exchange) 프로토콜을 제안하였지만, 이에 대한 안전성 증명이 없고 전방향 안전성을 제공하지 않는다. 본 논문에서는 새로운 CL-NIKE와 그에 대한 안전성 모델을 제안하고, 제안한 프로토콜이 해당 모델에서 안전함을 DBDH 가정(Decision Bilinear Diffie-Hellman Assumption)을 기반으로 증명한다. 추가적으로 다선형 함수(Multilinear map)를 사용한 개인키 업데이트를 통해 전방향 안전성을 만족하는 인증서 기반이 아닌 비대화형 키 교환 프로토콜을 제안하고 증명한다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 봄 학술발표논문집 Vol.30 No.1 (A)
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• pp.518-520
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• 2003

This paper proposes a new session key agreement scheme which is based on Station-to-station protocol, or STS shortly. We extend key agreement model of STS, to take into account smart cards. Besides, we modify STS to withstand message replaying attack. Security analysis shows our scheme is still secure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권12호
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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.

• IEIE Transactions on Smart Processing and Computing
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• 제2권3호
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• pp.168-175
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• 2013

Key escrow is a default property that is inherent in identity-based cryptography, where a curious private key generator (PKG) can derive a secret value shared by communicating entities in its domain. Therefore, a dishonest PKG can encrypt and decrypt ciphers or can carry out any attack on the communicating parties. Of course, the escrow property is not completely unwanted but is acceptable in other particular applications. On the other hand, in more civil applications, this key escrow property is undesirable and needs to be removed to provide maximum communication privacy. Therefore, this paper presents an escrow-free identity-based key agreement protocol that is also applicable even in a distinct PKG condition that does not use pairings. The proposed protocol has comparable computational and communicational performance to many other protocols with similar security attributes, of which their security is based on costly bilinear pairings. The protocol's notion was inspired by McCullagh et al. and Chen-Kudla, in regard to escrow-free and multi-PKG key agreement ideas. In particular, the scheme captures perfect forward secrecy and key compromise impersonation resilience, which were lacking in McCullagh et al.'s study, as well as all other desirable security attributes, such as known key secrecy, unknown key-share resilience and no-key control. The merit in the proposed protocol is the achievement of all required security requirements with a relatively lower computational overhead than many other protocols because it precludes pairings.

• 정보보호학회논문지
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• 제14권5호
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• pp.141-151
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• 2004

전자상거래의 활성화에 따라 이동매체의 안전에 대한 요구사항이 늘어나고 있다. 이동매체간의 호환성을 제공하기 위해서는 보안 API(Application Programming Interface)가 쉽고 안전하게 설계되어져야한다. 현재 많은 제품과 개발에 호환성과 확장성 표준을 제시하고 있는 RSA사의 PKCS(Public Key Cryptographic Standard) #11 인터페이스를 선택하여, 국내 전자서명 표준인 KCDSA(Korean Certificate-based Digital Signature Algorithm) 메커니즘을 제공하고자 한다. 그리고, PKCS #11 보안 API에 새로운 키 관리 함수를 정의하므로써 보다 더 안전한 키 관리 기능도 지원한다. KCDSA 개인키와 공개키의 객체 속성과 템플릿을 정의하고, KCDSA 메커니즘으로 전자서명을 생성하고 검증할 수 있도록 한다. KCDSA 메커니즘을 제공하는 PKCS #11을 설계 및 구현하여 성능평가하고, 보안성 및 호환성에 대하여 비교분석한다.

• ETRI Journal
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• 제32권2호
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• pp.204-213
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• 2010

In this paper, we investigate the possible security threats to downloadable conditional access system (DCAS) host devices. We then propose a DCAS secure micro (SM) and transport processor (TP) security protocol that counters identified security threats using a secure key establishment and pairing management scheme. The proposed protocol not only resists disclosed SM ID and TP ID threats and indirect connection between TA and TP threats, but also meets some desirable security attributes such as known key secrecy, perfect forward secrecy, key compromised impersonation, unknown key-share, and key control.

• 한국산학기술학회논문지
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• 제13권11호
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• pp.5487-5495
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• 2012

무선 센서 네트워크 환경에서 클러스터키 등의 보안키를 적용하기 위한 중요한 고려 사항은 보안키 갱신이 안전하게 이루어져야 하고, 보안키 갱신 시 요구되는 시간과 비용이 적어야 한다는 점이다. 각 센서 노드는 제한된 에너지를 보유하기 때문에 보안키 갱신에 소모되는 에너지가 클 경우 전체 네트워크 수명에 많은 영향을 준다. 따라서 안전하고 에너지 효율적인 보안키 관리 방법이 요구된다. 본 논문에서는 그룹을 기반으로 한 에너지 효율적인 클러스터키 관리 방안을 제안한다. 제안하는 방법에서 대규모 센서 네트워크에서 안전하고 효율적인 키 관리를 위해 5개의 보안키를 사용하고, 섹터, 클러스터 및 그룹 수준의 보안 적합도를 관리하여 보안키 갱신 주기 및 보안에 사용되는 다항식의 차수를 차별화시킨다. 실험을 통해 이전의 보안키 관리 기법보다 네트워크 에너지 효율성이 향상됨을 입증한다.