Catálogo de publicaciones - libros

We suggest a new intelligent ID-based threshold secure system by an encryption and decryption protocol using ( k , n )-threshold scheme which only k agents or more are engaged to reconstruct an encrypted data for a mobile intelligent system. Security issue protecting the network communication can be resolved by applying the Security Socket Layer. But the issue protecting the host against agent and the agent against malicious host can’t be resolve with this SSL. We aim that a protocol has to allow hosts to send and receive safely an encrypted data from the agents, even if some of the agents are compromised under the multi-agent roaming system. Since our secure system have the verification, the hosts and agents can be protected from each other.

For effectively facing information security threats under rapidly changing information-oriented environment, we need intelligent measuring the information security level of the whole enterprise organization. Most of the evaluation systems have performed evaluation with an emphasis on information security products so far. However, evaluating information security level for an enterprise needs analysis of the whole enterprise organization, and a synthetic and systematic evaluation system based on it. This study has tried to grasp the information security level of the whole enterprise organization, and develop an evaluation system of information security level for suggesting a more developing direction of information security with an intelligent agent.

In this paper, we present the merits of centralized approach for managing heterogeneous firewalls using multi-agents and implement the prototype of the central policy database that is a component of the PB-ISMSF (Policy-based Integrated Security Management System for Firewalls). Multi-agents initiate with SNMP security MIB, monitors the status of firewalls, and executes control requests from the PB-ISMSF engine. And also, we classified the policy conflicts, the condition of policy conflicts and briefly described the resolution methods for specified policy conflicts.

Adaptive modulation and coding (AMC), which has a number of variation levels in accordance with the fading channel variation, is a promising technique for communication systems. In this paper, the AMC method for OFDM system with cluster in pursuit of bandwidth efficiency and performance improvement is presented. And the AMC schemes applied into each cluster or some clusters are determined by the minimum or the average SNR value among all subcarriers within the corresponding cluster. It is important to find the optimal information related to cluster because AMC performance can be varied according to the number and position of cluster.

In order to achieve the maximum gain along the desired signal, this paper propose beamforming algorithm that utilize Generalized on-off algorithm. The new algorithm that provides a maximum SINR(Signal to Interference plus Noise Ratio) based on the conventional on-off algorithm for obtaining optimal weight vector. Also, in this paper, we present a novel demodulation method enhancing the performance of smart antenna by using the pilot channel of CDMA2000 1X channel to obtain the exact weight vector. From various computer simulation, we could conform that the proposed algorithm has superior performance in terms of SER(Symbol Error Rate) than conventional algorithm with multipath fading.

This paper designs and implements a unified and intelligent tool for vulnerability assessment which can efficiently assess vulnerabilities of computer systems in which functions of the vulnerability assessment were distributed. Developing a vulnerability assessment tool needs two steps; constructing a vulnerability analysis database and implementing a vulnerability assessment tool. The vulnerability analysis database is constructed based on CVE to report vulnerabilities in standard assessment result forms by updating newest information, and is organized to be suitable to the distributed network. The vulnerability assessment tool is implemented using Nessus and OVAL. The vulnerability assessment tool suggested in this paper can provide fast and more accurate vulnerability assessment and proper guidelines to corresponding vulnerabilities.

This paper aims at developing communication module and application program for client management module and developing database management module and managing wireless communication facilities for server systems. To construct these aims, we have adapted DES algorithm and researched on encrypting and decrypting module development applicable to SMS Security System and optimize module size and processing speed. In addition, the XML technology is applied to encrypt only the contents of the message in a way to reduce the volume of data to process and shorten the time to encrypting.

Because the networks and systems become more complex, the implementation of the security countermeasures becomes more critical consideration. The designers and developers of the security policy should recognize the importance of building security countermeasures by using both technical and non-technical methods, such as personnel and operational facts. Security countermeasures may be made for formulating an effective overall security solution to address threats at all layers of the information infrastructure. This paper uses the security engineering principles for determining appropriate security countermeasures. This paper proposes a intelligent method for building security countermeasures by modeling and dividing IT systems and security components into some blocks.

After a watermarked image is printed, copied several times and scanned, the watermark usually cannot be extracted rightly, as well as distorted by noise. In this paper, a spread spectrum technique was introduced to image watermarking which can be applied to print and generation copy. The watermarking message is modulated by the key-dependent pseudo-random sequences to produce a spread spectrum signal. The watermark is embedded into the cover image by modifying the gray value of each pixel. The cover image is not needed when the watermark is detected. The watermark is estimated exploiting the properties of HVS(Human Visual System) and extracted through the same key-dependent 2D sequences. Experimental results show that the scheme can resist print, generation copy and scan process.

Digital fingerprinting method allows individualization of all content purchased by users. In a multi-cast network, however, distributed contents must be identical among all users. Therefore, the process of individualizing content should be given on the user side while the original signal should not be delivered to users for security reasons related to copyright protection. Content fingerprinting (CoFIP) for audio signals was proposed to meet both requirements. In CoFIP, a problem might occur when users collude. Synchronous addition of several individualized audio signals makes it difficult to identify each individualized contents composed in it. This article proposes a countermeasure against such collusion, providing imperceptible phase shift in the individualization. Listening tests and computer simulations show that the fingerprint can be detected correctly while the sound quality of the colluded signal is effectively degraded.