Seung-Jo Han

The improved data encryption standard (DES) algorithm

The cryptosystem which is most used throughout the world for protecting information is the Data Encryption Standard (DES) which was announced by the National Bureau of Standard (NBS). The DES must be stronger than the other cryptosystems in its security. But, because the process time required for cryptanalysis has lessened, and because hardware technique has developed rapidly, the DES may be attacked by various kinds of cryptanalysis using parallel process. It may be especially vulnerable to attack by differential cryptanalysis. Therefore, the DES will require strengthening to ensure cryptographic security in the days to come. This paper proposes design of a DES-like cryptosystem called the Improved-DES. The Improved-DES is a new algorithm. We show that the Improved-DES is stronger than the DES against differential cryptanalysis for cryptographic security. We will divide one data block (96 bits) into 3 sub-blocks of 32 bits and then perform different f functions on each of the 3 sub-blocks, and then increase the S/sub 1/-S/sub 8/ of the S-boxes to S/sub 1/-S/sub 16/, satisfying the strict avalanche criterion (SAC: p/sub i, j/) and the correlation coefficient (p/sub i, j/). Finally we will increase the key length to 112 bits. The analysis will show that the unicity distance (UD) in the Improved-DES is increased more than the DESs UD.

Kerberos based authentication for inter-domain roaming in wireless heterogeneous network

An increased demand in ubiquitous high speed wireless access has led integration of different wireless technologies provided by different administrative domains creating truly a heterogeneous network. Security is one of the major hurdles in such network environment. As a mobile station moves in and out of the coverage area of one wireless network to another, it needs to be authenticated. The existing protocols for authentication of a mobile station are typically centralized, where the home network participates in each authentication process. It requires home network to maintain roaming agreement with all other visiting networks. Moreover, the round trip time to home network results high latency. This paper is focused on developing authentication protocol for wireless network irrespective of the technologies or the administrative domain. We propose a secure protocol which adopts strong features of Kerberos based on tickets for rigorous mutual authentication and session key establishment along with issuance of token so that the mobile station can have access to not only the roaming partner of home network but also to the roaming partner of previous visited networks. The performance evaluation and comparative analysis of the proposed protocol is carried out with the already implemented standard protocols and most remarkable research works till date to confirm the solidity of the results presented.

Vehicle Tracking Using Image Processing Techniques

A real time vehicle tracking in image sequences is presented. The moving vehicles are segmented by the method of differential image followed by the process of morphological dilation. The vehicles are recognized and tracked using statistical moments. The straight lines in the moving vehicles are found with the help of Radon transform. The direction of the moving object is calculated from the orientation of the straight lines in the direction of the principal axes of the moving objects. The direction of the moving object and the displacement of the object in the image sequence are used to calculate the velocity of the moving objects.

Evaluation of Secure Multimedia Services over Wireless Access Network

With growth of Internet and wireless IP network, multimedia systems can be accessed from any-where and anytime. However, efficient real-time services are open and challenging research problem. To implement real-time services such as VoIP over wireless access network, IP header compression scheme can be used for saving bandwidth. Enhanced compressed RTP (ECRTP) has been used for lossy link and high round trip time, primarily for wireless links. In this paper, we present an efficient solution for header compression, which is modified form of ECRTP. It shows an architectural framework for delivering real-time services to the wireless access network while using secure RTP (SRTP). We have conducted simulations to evaluate quality of services (QoS) of audio streaming.

RFID Mutual Autentication Protocol Using AES

Recently use of RFID(Radio Frequency Identification) tends to be rapidly increased and will be also extended throughout the whole life. Using radio-frequency data can be recognized automatically in the RFID system is vulnerable to personal information protection or security. And passive tags have a hardware problem is the limit for applying cryptographic. This paper presents an authentication protocol using AES and Nounce. After completing mutual authentication server to access and strengthen security vulnerability to the use of the Nounce, because safety in denial of service attacks.

Design of Zigbee Beacon Frame for High Efficiency Transmit in Home Network

Zigbee is communication technology most ideal because Zigbee support low power communication and wide expansion in wireless home network. However, Zigbee is not popular, because of Zigbee always has Hidden Node Problem and Transit Delay Problem. We propose new Beacon Frame structure to solve the two problem in Zigbee. New Beacon Frame structure reduces a Super Frame Duration and add a same space of a Control Frame Duration. We expect to solved method of Hidden Node Problem that exchange terminal information to using RTS/CTS. Also, We expect to solved method of Transit Delay Problem that put Beacon between Control Frame Duration and Super Frame Duration for synchronization. We confirm new Beacon Frame to solved two problem in OPNET simulation at Zigbee QoS Parameters. We measure Delay(sec) for solution degree of Transit Delay Problem, and measure Throughput(bits/sec) and Load (bits/sec) for solution degree of Hidden Node Problem.

Robust and Secure Voice Transmission over Wireless Mobile Ad Hoc Network

With the growth of the Internet services, Voice over IP (VoIP) has been playing a key role in cutting the costs of telephone calls. It can be seen that since demand of VoIP over wireless network is growing, use of VoIP over Mobile Ad Hoc Network (MANET) is expected to grow as well. We have identified many challenging issues to ensure robust and secure voice communication over MANET. In this paper, we depict a framework for robust and secure voice transmission over multipath MANET. We propose robust multipath routing protocol along with efficient traffic allocation approach as well as end-to-end security mechanisms for both routing and real-time traffic transfer. We conduct series of simulations to evaluate such a framework through different performance metrics.