• 디지털융복합연구
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• 제13권8호
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• pp.43-49
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• 2015

대표적인 융복합 ICT 서비스라고 할 수 있는 클라우드 컴퓨팅 서비스에 대한 법안이 2015년 3월에 통과되면서 많은 업체나 기관에서 다시금 클라우드 서비스 도입을 고려하고 있으나 보안에 대한 염려 때문에 서비스 도입을 주저하고 있다. 이러한 문제를 해결하기 위해서는 클라우드 서비스 보안에 대한 객관적이고 공정한 평가와 인증을 수행할 수 있는 클라우드 보안 인증체계의 도입이 요구된다. 현재 클라우드 보안 인증체계에 관한 연구가 활발히 진행되고 있지만 인증스킴에 대한 연구는 미흡하다. 따라서 본 연구는 국외 클라우드 보안 인증체계와 클라우드 서비스 제공자에 대한 평가 제도를 분석하여 국내 클라우드 보안 인증 도입시 고려되어야 할 요소들을 분석하였다. 이를 기반으로 국내 실정에 맞는 3가지 인증스킴을 제시하였고, 포커스 그룹 인터뷰를 통하여 인증스킴별 장단점을 도출하여 상황에 적절한 인증스킴을 제시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.4226-4241
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• 2014

Cloud storage provides an easy, cost-effective and reliable way of data management for users without the burden of local data storage and maintenance. Whereas, this new paradigm poses many challenges on integrity and privacy of users' data, since users losing grip on their data after outsourcing the data to the cloud server. In order to address these problems, recently, Worku et al. have proposed an efficient privacy-preserving public auditing scheme for cloud storage. However, in this paper, we point out the security flaw existing in the scheme. An adversary, who is on-line and active, is capable of modifying the outsourced data arbitrarily and avoiding the detection by exploiting the security flaw. To fix this security flaw, we further propose a secure and efficient privacy-preserving public auditing scheme, which makes up the security flaw of Worku et al.'s scheme while retaining all the features. Finally, we give a formal security proof and the performance analysis, they show the proposed scheme has much more advantages over the Worku et al.'s scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권11호
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• pp.5653-5672
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• 2019

In cloud computing era, an increasing number of resource-constrained users outsource their data to cloud servers. Due to the untrustworthiness of cloud servers, it is important to ensure the integrity of outsourced data. However, most of existing solutions still have challenging issues needing to be addressed, such as the identity privacy protection of users, the traceability of users, the supporting of dynamic user operations, and the publicity of auditing. In order to tackle these issues simultaneously, in this paper, we propose a traceable dynamic public auditing scheme with identity privacy preserving for cloud storage. In the proposed scheme, a single user, including a group manager, is unable to know the signer's identity. Furthermore, our scheme realizes traceability based on a secret sharing mechanism and supports dynamic user operations. Based on the security and efficiency analysis, it is shown that our scheme is secure and efficient.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2754-2767
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• 2019

Cloud computing is widely used in information spreading and processing, which has provided a easy and quick way for users to access data and retrieve service. Generally, in order to prevent the leakage of the information, the data in cloud is transferred in the encrypted form. As one of the traditional security technologies, access control is an important part for cloud security. However, the current access control schemes are not suitable for cloud, thus, it is a vital problem to design an access control scheme which should take account of complex factors to satisfy the various requirements for cipher text protection. We present a novel access control scheme based on proxy re-encryption(PRE) technology (PreBAC) for cipher text. It will suitable for the protection of data confidently and information privacy. At first, We will give the motivations and related works, and then specify system model for our scheme. Secondly, the algorithms are given and security of our scheme is proved. Finally, the comparisons between other schemes are made to show the advantages of PreBAC.

• International Journal of Computer Science & Network Security
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• 제24권1호
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• pp.140-150
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• 2024

Database-as-a-Service is one of the prime services provided by Cloud Computing. It provides data storage and management services to individuals, enterprises and organizations on pay and uses basis. In which any enterprise or organization can outsource its databases to the Cloud Service Provider (CSP) and query the data whenever and wherever required through any devices connected to the internet. The advantage of this service is that enterprises or organizations can reduce the cost of establishing and maintaining infrastructure locally. However, there exist some database security, privacychallenges and query performance issues to access data, to overcome these issues, in our recent research, developed a database security model using a deterministic encryption scheme, which improved query execution performance and database security level.As this model is implemented using a deterministic encryption scheme, it may suffer from chosen plain text attack, to overcome this issue. In this paper, we proposed a new model for cloud database security using nondeterministic encryption, order preserving encryption, homomorphic encryptionand database distribution schemes, andour proposed model supports execution of queries with equality check, range condition and aggregate operations on encrypted cloud database without decryption. This model is more secure with optimal query execution performance.

• 정보보호학회논문지
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• 제29권3호
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• pp.599-612
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• 2019

클라우드 네트워크는 다양한 서비스 제공을 위해 활용된다. 클라우드 네트워크를 활용한 서비스 제공이 확대되면서, 다양한 환경과 프로토콜을 활용하는 자원들이 클라우드에 다수 존재하게 되었다. 하지만 이러한 자원들에 대한 보안 침입이 발생하고 있으며, 클라우드 자원에 대한 위협들이 등장함에 따라 클라우드 네트워크 취약점 탐지에 대한 연구가 요구된다. 본 논문에서는 다양한 환경과 프로토콜을 활용하는 자원들에 대한 취약점 탐지를 위해 STRIDE와 HARM을 활용한 취약점 탐지 기법을 제시하고 취약점 탐지 시나리오 구성을 통해 클라우드 네트워크 취약점 탐지 기법에 대해 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권11호
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• pp.4522-4536
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• 2020

Nowadays, cloud is the fastest emerging technology in the IT industry. We can store and retrieve data from the cloud. The most frequently occurring problems in the cloud are security and privacy preservation of data. For improving its security, secret information must be protected from various illegal accesses. Numerous traditional cryptography algorithms have been used to increase the privacy in preserving cloud data. Still, there are some problems in privacy protection because of its reduced security. Thus, this article proposes an ElGamal Elliptic Curve (EGEC) Homomorphic encryption scheme for safeguarding the confidentiality of data stored in a cloud. The Users who hold a data can encipher the input data using the proposed EGEC encryption scheme. The homomorphic operations are computed on encrypted data. Whenever user sends data access permission requests to the cloud data storage. The Cloud Service Provider (CSP) validates the user access policy and provides the encrypted data to the user. ElGamal Elliptic Curve (EGEC) decryption was used to generate an original input data. The proposed EGEC homomorphic encryption scheme can be tested using different performance metrics such as execution time, encryption time, decryption time, memory usage, encryption throughput, and decryption throughput. However, efficacy of the ElGamal Elliptic Curve (EGEC) Homomorphic Encryption approach is explained by the comparison study of conventional approaches.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권7호
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• pp.2719-2735
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• 2015

In the cloud environment, users pay more attentions to their data security since all of them are stored in the cloud server. Researchers have proposed many mutual authentication schemes for the access control of the cloud server by using the smart card to protect the sensitive data. However, few of them can resist from the smart card lost problem and provide both of the forward security and the backward security. In this paper, we propose a novel authentication scheme for cloud computing which can address these problems and also provide the anonymity for the user. The trick we use is using the password, the smart card and the public key technique to protect the processes of the user's authentication and key exchange. Under the Elliptic Curve Diffie-Hellman (ECDH) assumption, it is provably secure in the random oracle model. Compared with the existing smart card based authentication schemes in the cloud computing, the proposed scheme can provide better security degree.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제10권12호
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• pp.595-602
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• 2021

로봇은 주변 상황을 인지하고 Task를 부여받는 software oriented 형상으로 발전하고 있다. Cloud Robotics Platform은 로봇에 Service Oriented Architecture 형상을 지원하기 위한 방법으로, 상황에 따라 필요한 Task와 Motion Controller를 클라우드 기반으로 제공할 수 있는 방안이다. 휴머노이드 로봇으로 진화할수록 로봇은 로봇 3대 원칙에 따라 보편화된 일상생활 속에서 인간에게 도움을 주기 위해 사용될 것이다. 따라서 특정 개인만을 위한 로봇 이외에도, 상황에 따라 모든 인간에게 도움을 줄 수 있는 공공재로써의 로봇이 보편화될 것이다. 따라서, 생성하는 정보는 사람, 로봇, 로봇에 지능을 부여하는 클라우드 상의 서비스 애플리케이션, 로봇과 클라우드를 이어주는 클라우드 브릿지로 구성될 것으로 분석되는 Cloud Robotics Computing 환경에서 정보보안의 중요성은 인간의 생명 및 안전을 위해 필수불가결한 요소로 자리잡게 될 것이다. 본 논문에서는 지능화된 로봇을 위한 Cloud Robotics Computing 환경에서 사람, 로봇, 클라우드 브릿지, 클라우드 시스템간 통신 시 보안을 제공하여 해킹으로부터 안전하고 개인의 정보가 보호되는 로봇 서비스가 가능할 수 있는 Security Scheme을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권9호
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• pp.4576-4598
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• 2018

In big data age, flexible and affordable cloud storage service greatly enhances productivity for enterprises and individuals, but spontaneously has their outsourced data susceptible to integrity breaches. Provable Data Possession (PDP) as a critical technology, could enable data owners to efficiently verify cloud data integrity, without downloading entire copy. To address challenging integrity problem on multiple clouds for multiple owners, an identity-based batch PDP scheme was presented in ProvSec 2016, which attempted to eliminate public key certificate management issue and reduce computation overheads in a secure and batch method. In this paper, we firstly demonstrate this scheme is insecure so that any clouds who have outsourced data deleted or modified, could efficiently pass integrity verification, simply by utilizing two arbitrary block-tag pairs of one data owner. Specifically, malicious clouds are able to fabricate integrity proofs by 1) universally forging valid tags and 2) recovering data owners' private keys. Secondly, to enhance the security, we propose an improved scheme to withstand these attacks, and prove its security with CDH assumption under random oracle model. Finally, based on simulations and overheads analysis, our batch scheme demonstrates better efficiency compared to an identity based multi-cloud PDP with single owner effort.