• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.180-180
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• 2012

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.773-777
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• 2008

Today's mobile devices have characteristic of random mobility in the heterogeneous networks. Thus they should have various kinds of security requirements. To satisfy these requirements, there are many researches on security and authentication for mobile devices. TCG(Trusted Computing Group) designed TPM(Trusted Platform Module) for providing privacy and authentication to users. Also TCG suggest a protocol, called DAA(Direct Anonymous Attestation) which uses zero knowledge proof theory. In this paper, we will implement DAA protocol using Java and show the efficiency and the problems in the DAA protocol. Finally, we will suggest an efficient mobile DAA model through Java test module for the DAA protocol.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.95-105
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• 2010

DNS(Domain Name System) is a huge distributed database that converts host name to IP address. We are expecting the importance of DNS is more increased because many Internet application services appear according to the continuous increase of Internet users and nearly all the Internet application services use DNS. To prevent the interruption of DNS service, DNS server is configured with primary DNS server and a secondary DNS server which takes the place of primary DNS server in case of the service interruption. But this scheme is difficult for providing DNS service constantly in case of DDoS attack, which brings about much network load or network problems in DNS server group. Therefore, This paper proposed the scheme to locally distribute load of DNS server, and the use of address system to group the distributed DNS servers. Also, it proposed the authentication scheme of the correspondent server in case the server is changed in DNS server group having grouping address. In this paper, it is shown that the prosed scheme guarantees the improved service reliability with maintaining the present service performance through the evaluation. Through this, we can expect the high improved DNS service can be provided in the Internet environment in the future.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.243-248
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• 2014

The demand for messenger service goes on growing rapidly with widespread use of smartphones. Generally, the smartphone messenger provides group communication functions in which users can make the group and communicate with each other. In the mobile meeting, the attendees can participate in the meeting with use of smartphone messengers wherever they are. To make the mobile meeting put to practical use, the mobility and privacy should be ensured to attendees. To satisfy the mobility requirement, the user which is not belong to the group members should not be able to participate in the meeting. To ensure the privacy requirement, the attendees should have not to repudiate the meeting results. In this study, the mobile meeting authentication scheme is proposed which provides mobility and privacy. The proposed scheme consists of meeting group creation, group key generation, group signature and verification protocols. All attendees should have to participate in the signature verification because it is based on the challenge-response type protocol. Thus, it's not possible to collude with malicious attendees to change the meeting results.

• Journal of KIISE:Information Networking
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• v.31 no.5
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• pp.429-437
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• 2004

The mobileip working group is equipped with the RR(Return Routabilit) taking the simple procedures and small amount of cryptographic operations by considering the processing capability of the mobile node however it dose not provide security features enough. To replace with enhanced methods, mobileip WG is making an effort to find the approved solutions include CGA(Craptographically Generated Address), IPsec(Internet Protocol Security) as well as the existing infrastructure such as AAA(Authentication, Authorization and Account) and PKI(Public Key Infrastructure). In this paper, we propose the authentication and route optimization based on AAA suitable for the requested security service for its successful story in wireless network such as 802.11 and 3GPP(3rd Generation Partnership Project) as well as wired one. We analyze the effectiveness of our scheme according to the traffic and mobility properties. The result shows the cost reduction up to 20 percent comparing with RR.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.9
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• pp.707-714
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• 2013

IoT, which can be regarded as an enhanced version of M2M communication technology, was proposed to realize intelligent thing to thing communications by utilizing Internet connectivity. Things in IoT are generally heterogeneous and resource constrained. Also such things are connected with each other over LLN(low power and lossy Network). Confidentiality, mutual authentication and message origin authentication are required to make a secure service in IoT. Security protocols used in traditional IP Networks cannot be directly adopted to resource constrained devices in IoT. Under the respect, a IETF standard group proposes to use lightweight version of DTLS protocol for supporting security services in IoT environments. However, the protocol can not cover up all of very constrained devices. To solve the problem, we propose a scheme which tends to support mutual authentication and session key agreement between devices that contain only a single crypto primitive module such as hash function or cipher function because of resource constrained property. The proposed scheme enhances performance by pre-computing a session key and is able to defend various attacks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.8
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• pp.2827-2848
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• 2021

Mobile Crowdsourcing (MCS) has become an emerging paradigm evolved from crowdsourcing by employing advanced features of mobile devices such as smartphones to perform more complicated, especially spatial tasks. One of the key procedures in MCS is to collect answers from mobile users (workers), which may face several security issues. First, authentication is required to ensure that answers are from authorized workers. In addition, MCS tasks are usually location-dependent, so the collected answers could disclose workers' location privacy, which may discourage workers to participate in the tasks. Finally, the overhead occurred by authentication and privacy protection should be minimized since mobile devices are resource-constrained. Considering all the above concerns, in this paper, we propose a lightweight and privacy-preserving answer collection scheme for MCS. In the proposed scheme, we achieve anonymous authentication based on traceable ring signature, which provides authentication, anonymity, as well as traceability by enabling malicious workers tracing. In order to balance user location privacy and data availability, we propose a new concept named current location privacy, which means the location of the worker cannot be disclosed to anyone until a specified time. Since the leakage of current location will seriously threaten workers' personal safety, causing such as absence or presence disclosure attacks, it is necessary to pay attention to the current location privacy of workers in MCS. We encrypt the collected answers based on timed-release encryption, ensuring the secure transmission and high availability of data, as well as preserving the current location privacy of workers. Finally, we analyze the security and performance of the proposed scheme. The experimental results show that the computation costs of a worker depend on the number of ring signature members, which indicates the flexibility for a worker to choose an appropriate size of the group under considerations of privacy and efficiency.

• The Korea Journal of Herbology
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• v.29 no.6
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• pp.45-53
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• 2014

Objectives : Due to the morphological similarity of in the roots of herbal medicine, the official herbal medicine is very difficult to authenticate between the original plants of Patriniae Radix and two adulterant Patrinia species. Therefore, we introduced DNA barcode analysis to establish a powerful tool for the authentication of Patriniae Radix from its adulterants. Methods : To analyze DNA barcode regions, genomic DNA was extracted from twenty-nine specimens of Patrinia scabiosaefolia, Patrinia villosa, Patrinia saniculifolia, and Patrinia rupestris, and internal transcribed spacer 2(ITS2), matK and rbcL genes were amplified. For identification of species specific sequences, a comparative analysis was performed by the ClastalW based on entire sequences of ITS2, matK and rbcL genes, respectively. Results : In comparison of three DNA barcode sequences, we identified 22, 22, and 12 species-specific nucleotides enough to distinguish each four species from ITS2, matK and rbcL gene, respectively. The sequence differences at the corresponding positions were available genetic marker nucleotides to discriminate the correct species among analyzed four species. These results indicated that comparative analysis of ITS2, matK and rbcL genes were useful genetic markers to authenticate Patriniae Radix. Conclusions : The marker nucleotides enough to distinguish P. scabiosaefolia, P. villosa, P. saniculifolia, and P. rupestris, were obtained at 22 SNP marker nucleotides from ITS2 and matK DNA barcode sequences, but they were confirmed at 12 SNP marker nucleotides from rbcL. These differences could be used to authenticate Patriniae Radix from its adulterants as well as discriminating each four species.

• Journal of Convergence Society for SMB
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• v.4 no.3
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• pp.21-25
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• 2014

Group communications are becoming popular in Internet applications such as video conferences, on-line chatting programs, games, and gambling. Secure and efficient group communication is needed for message integration, confidentiality, and system usability. However, the conventional group key agreement protocols are too much focused on minimizing the computational overhead by concentrating on generating the common group key efficiently for secure communication. As a result, the common group key is generated efficiently but a failure in authentication allows adversaries to obtain valuable information during the group communication. After achieving the secure group communication, the secure group communication should generate the group key efficiently and distribute it to group members securely, so the balance of security and system usage must be considered at the same time. Therefore, this research proposes the software architecture model of a secure and efficient group communication that will be imbedded into networking applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.935-949
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• 2016

In this paper, we present a novel authenticated group key distribution scheme for large and dynamic multicast groups without employing traditional symmetric and asymmetric cryptographic operations. The security of our scheme is mainly based on the basic theories for solving linear equations. In our scheme, a large group is divided into many subgroups, where each subgroup is managed by a subgroup key manager (SGKM) and a group key generation center (GKGC) further manages all SGKMs. The group key is generated by the GKGC and then propagated to all group members through the SGKMs, such that only authorized group members can recover the group key but unauthorized users cannot. In addition, all authorized group members can verify the authenticity of group keys by a public one-way function. The analysis results show that our scheme is secure and efficient, and especially it is very appropriate for secure multicast communications in large and dynamic client-server networks.