• Journal of Internet Computing and Services
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• v.11 no.6
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• pp.87-110
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• 2010

Recently competitive Korean companies are suffered from financial loss due to illegal exposure of their own proprietary know-how secrets, since it is difficult to watch hidden illegal channels to leak them due to their digitalization. Today the DRM-based system designed to protect such secrets is insufficient to prevent it, since DRM-based protection system cannot defend the intelligent robbery of secrets, in special, employee's robbery. The MSEC is much appropriate to secure secrets against employee's robbery. Our paper notes that IGMP, MSEC and SNMP can work easily together to realize secure system that satisfy strong security condition for prevention from leaking secrets. Since the previous research was on the architectural design for prevention of illegal exposure, this paper proposes the efficient protocol based on MSEC protocol. Our protocol satisfies the strong security conditions that the principles that the secret should be stored/distributed only in an encrypted shape, and should be separated physically from its encryption key, and should be carried in registered mobile storage separate from its processing device, and should be verified in terms of both user and device. Thus this paper proposes both the protocol for secret document distribution and its group key management.

• Journal of Advanced Navigation Technology
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• v.17 no.1
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• pp.24-32
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• 2013

Authentication is one of the necessary elements in the network environment. Many researches have detected security vulnerabilities to the existing authentication mechanisms and suggested secure mutual authentication protocols by resolving these vulnerabilities. The representative ones of them are SPMA(Strong Pass Mutual Authentication) and I-SPMA(Improved Strong Password Mutual Authentication). However, these protocols cause a critical problem when the shared secret information is de-synchronized between the server and the client. This paper proposes a revised protocol to resolve the de-synchronization problem. Based on a security assessment on the proposed protocol, we consider the proposed protocol is safer than the previous ones and possible to effectively make a user authentication system mre secure.

• Journal of the Korea Computer Industry Society
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• v.2 no.10
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• pp.1269-1284
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• 2001

The Secure Sockets Layer is a protocol for encryption TCP/IP traffic that provides confidentiality, authentication and data integrity. Also the SSL is intended to provide the widely applicable connection-oriented mechanism which is applicable for various application-layer, for Internet client/server communication security. SSL, designed by Netscape is supported by all clients' browsers and server supporting security services. Now the version of SSL is 3.0. The first official TLS vl.0 specification was released by IETF Transport Layer Security working group in January 1999. As the version of SSL has had upgraded, a lot of vulnerabilities were revealed. SSL and TLS generate the private key with parameters exchange method in handshake protocol, a lot of attacks may be caused on this exchange mechanism, also the same thing may be come about in record protocol. In this paper, we analyze SSL protocol, compare the difference between TLS and SSL protocol, and suggest what developers should pay attention to implementation.

• The KIPS Transactions:PartC
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• v.14C no.1 s.111
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• pp.55-64
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• 2007

Behind the popularity of VoIP in these days, it may present significant security challenges in privacy and accounting. Authentication and message encryption are considered to be essential mechanisms in VoIP to be comparable to PSTN. SIP is responsible for setting up a secure call in VoIP. SIP employs TLS, DTLS or IPSec combined with TCP, UDP or SCTP as a security protocol in VoIP. These security mechanisms may introduce additional overheads into the SIP performance. However, this overhead has not been understood in detail by the community. In this paper we present the effect of the security protocol on the performance of SIP by comparing the call setup delays among security protocols. We implement a simulation of the various combinations of three security protocols and three transport layer protocols suggested for SIP. UDP with any combination of security protocols performs a lot better than the combination of TCP. TLS over SCTP may impose higher impact on the performance in average because TLS might have to open secure channels as the same number of streams in SCTP. The reasons for differences in the SIP performances are given.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1597-1605
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• 2015

Password authenticated key exchange (PAKE) is a protocol that a client stores its password to a server, authenticates itself using its password and shares a session key with the server. In multi-server PAKE, a client splits its password and stores them to several servers separately. Unless all the servers are compromised, client's password will not be disclosed in the multi-server setting. In attribute-based encryption (ABE), a sender encrypts a message M using a set of attributes and then a receiver decrypts it using the same set of attributes. In this paper, we introduce multi-server PAKE protocol that utilizes a set of attributes of ABE as a client's password. In the protocol, the client and servers do not need to create additional public/private key pairs because the password is used as a set of public keys. Also, the client and the servers exchange only one round-trip message per server. The protocol is secure against dictionary attacks. We prove our system is secure in a proposed threat model. Finally we show feasibility through evaluating the execution time of the protocol.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3C
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• pp.426-435
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• 2004

The DIAMETER protocol provides Authentication, Authorization, and Accounting (AAA) transactions across the Internet. SIP(Session Initiation Protocol) will be used for new types of signaling, such as instant messaging and application level mobility across networks. And SIP will be a major signaling protocol for next generation wireless networks. But the Digest authentication scheme is not using a secure method of user authentication in SIP, and it is vulnerable to man-in-the-middle attacks or dictionary attacks. This study focused on designing a SIP proxy for interworking with AAA server with respect to user authentication and security analysis. We compared and analyzed the security aspects of the scenarios and propose two proposals that a response which include the user address and password-based mutual authentication and key agreement protocol. It is claimed to be more secure against common attacks than current scenarios.

• The KIPS Transactions:PartC
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• v.16C no.2
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• pp.199-208
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• 2009

Recently,IP-based broadcasting systems,such as Mobile-TV and IP-TV, have been widely deployed. These systems require a security system to allow only authorized subscribers access to broadcasting services. We analyzed the Conditional Access System, which is a security system used in the IP-based Pay-TV systems. A weakness of the system is that it does not scale well when the system experiences frequent membership changes. In this paper, we propose a group key distribution protocol which overcomes the scalability problem by reducing communication and computation overheads without loss of security strength. Our experimental results show that computation delay of the proposed protocol is smaller than one of the Conditional Access System. This is attributed to the fact that the proposed protocol replaces expensive encryption and decryption with relatively inexpensive arithmetic operations. In addition, the proposed protocol can help to set up a secure channel between a server and a client with the minimum additional overhead.

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.845-858
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• 2020

This paper proposes a modified end-to-end secure low energy adaptive clustering hierarchy (ME-LEACH) algorithm for enhancing the lifetime of a wireless sensor network (WSN). Energy limitations are a major constraint in WSNs, hence every activity in a WSN must efficiently utilize energy. Several protocols have been introduced to modulate the way a WSN sends and receives information. The end-to-end secure low energy adaptive clustering hierarchy (E-LEACH) protocol is a hierarchical routing protocol algorithm proposed to solve high-energy dissipation problems. Other methods that explore the presence of the most powerful nodes on each cluster as cluster heads (CHs) are the sparsity-aware energy efficient clustering (SEEC) protocol and an energy efficient clustering-based routing protocol that uses an enhanced cluster formation technique accompanied by the fuzzy logic (EERRCUF) method. However, each CH in the E-LEACH method sends data directly to the base station causing high energy consumption. SEEC uses a lot of energy to identify the most powerful sensor nodes, while EERRCUF spends high amounts of energy to determine the super cluster head (SCH). In the proposed method, a CH will search for the nearest CH and use it as the next hop. The formation of CH chains serves as a path to the base station. Experiments were conducted to determine the performance of the ME-LEACH algorithm. The results show that ME-LEACH has a more stable and higher throughput than SEEC and EERRCUF and has a 35.2% better network lifetime than the E-LEACH algorithm.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.4
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• pp.21-35
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• 2007

In ad hoc networks, position-based routing schemes, that use geographical positions of nodes, have been proposed to efficiently route messages. In these routing schemes, the location service is one of the key elements that determines and effects security and efficiency of the protocol. In this paper, we define security threats of location service and propose a new quorum based location service protocol. In our proposed protocol, nodes register their public keys in other nodes during the initialization phase and these registered keys are used to verify locations of other nodes and the messages exchanged. In this paper, we prove that our protocol is robust against traditional attacks and new attacks that may occur due to the use of position-based routing. We also analyze the efficiency of our protocol using various simulations.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.4
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• pp.13-26
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• 2006

RFID technology is evaluated as one of core technologies for ubiquitous environment, because of its various characteristics which barcode systems don't have. However, RFID systems have consumer's privacy infringement problems, such like information leakage and location tracing. We need RFID privacy protection protocols, that satisfy three essential security requirements; confidentiality, indistinguishability and forward security, in order to protect consumer's privacy perfectly. The most secure protocol, that satisfies all of the three essential security requirements, among existing protocols, is the hash-chain based protocol that Ohkubo proposed. Unfortunately this protocol has a big disadvantage that it takes very long time to identify a tag in the back-end server. In this paper, we propose a scheme to keep security just as it is and to reduce computation time for identifying a tag in back-end server. The proposed scheme shows the results that the identification time in back-end server is reduced considerably compared to the original scheme of Ohkubo protocol.