• The Transactions of the Korea Information Processing Society
• /
• v.2 no.6
• /
• pp.866-878
• /
• 1995

This paper explains design and implementation of Multimedia E-mail system as a research on multimedia service. It is based on MIME(Multipurpose Internet Mail Extensions) which extends RFC822. MIME is a standard mail tran sfer protocol which can include multiple objects in a single message, represent non-textual material such as images and audio, exchange without loss of multimedia information through SMTP(Simple Mail Transfer Protocol). It is implementation of Multimedia Mail system which can store, delete, edit and tran sfer multimedia mail misgave in user friendly way on UNIX system. It aims tp develope framework for multimedia E-mail system.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.4 no.4
• /
• pp.41-49
• /
• 2008

Sensor networks are often deployed in unattended environments, thus leaving these networks vulnerable to false data injection attacks in which an adversary injects forged reports into the network through compromised nodes. Such attacks by compromised sensors can cause not only false alarms but also the depletion of the finite amount of energy in a battery powered network. In order to reduce damage from these attacks, several security solutions have been proposed. Researchers have also proposed some techniques to increase the energy-efficiency of such security solutions. In this paper, we propose a CH(Cluster Header) selection algorithm to choose low power delivery method in sensor networks. The CNP(Contract Net Protocol), which is an approach to solve distribution problems, is applied to choose CHs for event sensing. As a result of employing CNP, the proposed method can prevent dropping of sensing reports with an insufficient number of message authentication codes during the forwarding process, and is efficient in terms of energy saving.

• Journal of KIISE:Information Networking
• /
• v.34 no.2
• /
• pp.134-142
• /
• 2007

Several mobility supporting protocols have been proposed across OSI reference layers. Each protocol has similar or different characteristics based on its operating layer which affect a handover latency. In this paper, we analyze handover performance of most representative protocols in each layer. For analysis, we use SUBNET model based Markovian model and movement model. In result, difference of protocol handover latency is not occurred by DAD but also by security, movement detection, message processing time.

• Journal of Korea Multimedia Society
• /
• v.21 no.8
• /
• pp.897-908
• /
• 2018

In this paper, we propose a security framework for a cluster drones network using the MAVLink (Micro Air Vehicle Link) application protocol based on FANET (Flying Ad-hoc Network), which is composed of ad-hoc networks with multiple drones for IoT services such as remote sensing or disaster monitoring. Here, the drones belonging to the cluster construct a FANET network acting as WTRP (Wireless Token Ring Protocol) MAC protocol. Under this network environment, we propose an efficient algorithm applying the Lightweight Encryption Algorithm (LEA) to the CTR (Counter) operation mode of WPA2 (WiFi Protected Access 2) to encrypt the transmitted data through the MAVLink application. And we study how to apply LEA based on CBC (Cipher Block Chaining) operation mode used in WPA2 for message security tag generation. In addition, a modified Diffie-Hellman key exchange method is approached to generate a new key used for encryption and security tag generation. The proposed method and similar methods are compared and analyzed in terms of efficiency.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.2
• /
• pp.361-365
• /
• 2005

Proxy signature schemes which allows original signer to delegate proxy signer to sign message on its behalf have a considerable amount of interest from researchers since Mambo[1] and have found many practical applications such as distributed network, Grid computing and electronic commerce. Araki[6] extended them to multi-level proxy signature. But it could not satisfy some security requirement. In this paper we propose a protocol to delegate signing right to another entity for multi-level proxy signature. Our protocol do not require secure channel and guarantee that nobody is able to repudiate delegation or acceptance of signing right, it is impossible for anyone to generate signature except designed and original signer can withdraw the delegation before expiration if it is necessary.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.1
• /
• pp.119-124
• /
• 2016

In this paper, we studied on MAC(Media Access Control) protocol for UAVs application. According to the number of UAVs, ground control station should control properly increased UAVs. So, we applied CSMA/CA that used in current civil aircraft to UAV communications and verified the applicability through comparison of throughput and delays of data with various message sizes, In the results, we confirmed applicability for UAVs MAC protocol.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.7A
• /
• pp.973-986
• /
• 1999

In this paper, we propose MAC protocol that consists of channel access mechanism and transmission mechanism to support effective wireless packet data service. In channel access mechanism, broadcast channel announces status information of random access channel, and mobile station tries random access based on status information. Also, mobile station has access probability to prevent collision increase due to transmission of short message. For effective transmission, mobile station changes transmission rate based on transmission queue status to adapt burst traffic characteristics. In restricted environments of transmission code and bandwidth, proposed protocol shows better performance than cdma2000 system.

• Journal of KIISE:Information Networking
• /
• v.30 no.2
• /
• pp.189-198
• /
• 2003

As people are damaged increasingly by personal information leakage, awareness about user privacy infringement is increasing. However, the existing DRM system does not support the protection of user's personal information because it is not necessary for the protection of copyrights. This paper is suggesting a license administration protocol which is more powerful to protect personal information in DRM. To protect the exposure of users identifier, this protocol uses temporary ID and token to guarantee anonymity and it uses a session key by ECDH to cryptography and Public-Key Cryptosystem for a message so that it can protect the exposure of personal information and user's privacy.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.4
• /
• pp.23-28
• /
• 2013

In this paper, we propose a simple bidirectional transmission protocol using network coding and digital Fountain codes. In particular, in the proposed scheme, two sources use digital Fountain codes to transmit their message to each other with the help of relays. Then, relays use Fountain codes and network coding to forward the source messages to both sources. To evaluate performance of the proposed protocols, we present the average total throughput over Rayleigh fading channels via Various Monte-Carlo simulations. Results show that the proposed protocol outperforms the two-way relaying transmission protocol without using network coding technique at high SNR region.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.312-313
• /
• 2017

Internet of Things(IoT) is an intelligent technology and service in which all objects communicate with each other through various networks. Recently Internet of Things(IoT) is one of the fields that is attracting attention as the development of ICT industry. MQTT is a protocol which is safe using TLS or adopting light packet structure for effciency of memory and power using. In this paper, when TLS is used the process of encryption / decryption in the broker occurs. We propose an efficient MQTT protocol through centralized key management by adding authentication server.