• Journal of Korea Society of Industrial Information Systems
• /
• v.9 no.4
• /
• pp.41-46
• /
• 2004

This paper presents a new semi- systolic architecture for $AB^2$ operation. First of all the previous architecture proposed by Lee et al. is analysed and then we present a new algorithm and it's architecture for $AB^2$ operation based on AOP (all one polynomial) to solve the shortcomings in the architecture. Proposed architecture has an efficient configuration than other previous architectures. It is useful for implementing the exponentiation architecture, which is the core operation in public-key cryptosystems.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.6B
• /
• pp.1059-1067
• /
• 1999

In this paper characteristics of ATM-PON is described and a TC layer controller for ATM-PON OLT is designed. This paper proposes an algorithm of economically controlling the grant information written by CPU to dynamically allocate the upstream bandwidth on the PON among the ONUs in a fair way and of encrypting the downstream data using a lower standard of encryption, termed data churning, which is used to distinguish it from existing transmission system scramblers and higher layer encryption methods. This paper also proposes a method of allocating churning-related message into the PLOAM cell in order to synchronously change the churning key between the OLT and the ONU.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.5
• /
• pp.1017-1026
• /
• 2012

Due to acceleration of the IT industry and the environment for a variety of media in modern society, such as real-time video images 3D-TV is a very important issue. These high-quality live video is being applied to various fields such as CCTV footage has become an important performance parameters. However, these high quality images, even vulnerable because of shortcomings secure channel or by using various security algorithms attempt to get rid of these disadvantages are underway very active. These shortcomings, this study added extra security technologies to reduce the processing speed image processing itself, but by adding security features to transmit real-time processing and security measures for improving the present.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.8
• /
• pp.1207-1212
• /
• 2013

Arithmetic operations over finite fields are widely used in coding theory and cryptography. In both of these applications, there is a need to design low complexity finite field arithmetic units. The complexity of such a unit largely depends on how the field elements are represented. Among them, representation of elements using a optimal normal basis is quite attractive. Using an algorithm minimizing the number of 1's of multiplication matrix, in this paper, we propose a multiplier which is time and area efficient over finite fields with optimal normal basis.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.5
• /
• pp.1209-1223
• /
• 2018

Android apps are made up of bytecode, so they are vulnerable to reverse engineering, and protection services are emerging that robustly repackage the app to compensate. Unlike cryptographic algorithms, the robustness of these protection services depends heavily on hiding the protection scheme. Therefore, there are few systematic discussions about the protection method even if destruction techniques of the protection service are various. And it is implemented according to the intuition of the developer. There is a need to discuss systematic protection schemes for robust security chains, rather than simple deployment of techniques disrupting static or dynamic analysis. In this paper, we analyze bangcle, a typical commercial Android app protection service, to examine the protection structure and vulnerable elements. We propose the requirements for robust structure and principles of protection structure.

• The KIPS Transactions:PartC
• /
• v.8C no.5
• /
• pp.551-556
• /
• 2001

The ESES system has been developed to supply a digital signature function, an encryption function, and a library of cryptographic primitives and algorithm for securing an XML document and the existing non-XML documents that are exchanged in the electronic commerce. In this paper, we will introduce the overview of ESES system and explain how the ESES processes to offer security services Finally we\`ll conclude our talk by presenting the summary and further works.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.3 no.4
• /
• pp.308-312
• /
• 2002

Recently, Internet is getting more popular and the usage of multimedia contents is getting more increased. Among the multimedia contents, the JPEG format is the most commonly used Image data format but the JPEG format doesn't supply cryptographic methods and access control. In this paper, a cryptographic method for cipher JPEG Image is proposed. This method can supply encryption and decryption using several algorithms such as DES to the JPEG Image data. Huffman table, which is the most important data area for JPEG data coding, is chosen as the coding data. Each method is compared to select the optimal cryptographic method in a certain environment.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2002.05d
• /
• pp.941-946
• /
• 2002

지문인식 시스템이 네트워크 기반에서 서버 매칭 형식으로 운영될 경우 클라이언트 매칭과는 달리 데이터의 전송과정에 많은 취약성이 존재한다. 지문인식은 휴대의 불편함이 없고, 분실이나 도난의 위험성도 없으며, 추측이 거의 불가능하므로 높은 안전성을 제공하는 장점을 가지고 있다. 그러나 지문데이터는 한 번 도난을 당하거나 네트워크 상에서 전송 도중 공격자를 통해 도청이 된다면 그 사용자는 앞으로 지문인식을 이용할 수 없다는 단점이 존재한다. 이에 대하여 전송 포맷 기술과 전송 데이터 보안의 표준화가 이루어지고 있다. 따라서 본 논문에서는 클라이언트에서 추출한 지문 특징점 데이터를 매칭을 위해 서버로 데이터를 전송할 경우 무결성의 적합성을 검증하기 위한 도구를 구현하였다. 신분위장 및 재전송 공격들의 위협으로부터 안전한 사용자 신분 확인을 보장하기 위해서 전송되는 지문 데이터의 인중, 무결성, 기밀성이 요구되며, 이를 위해 지문 데이터의 MAC(Message Authentication Code)과 암호화 기법을 이용하였다. 이때 전송 데이터의 기밀성을 위해서 Triple-DES와 SEED 암호 알고리즘을 사용하였고 무결성을 위해 MD5와 SHA-1 해쉬 함수를 사용하였다. 클라이언트에서 데이터를 전송할 때 두 가지의 지문데이터를 전송하는 실험을 통하여 결과를 비교하였다. 첫째, 변조된 지문데이터를 전송하였을 경우 데이터가 변조되었음을 알려주는 결과를 보여준다. 둘째, 변조되지 않은 지문데이터를 전송하였을 경우 이 데이터는 변조되었다는 메시지를 출력함으로써 무결성 검증 실험은 이루어진다.

• The Transactions of the Korea Information Processing Society
• /
• v.3 no.2
• /
• pp.225-230
• /
• 1996

We propose a statistical test for the nonlinear combiner logics which are usually combined with two maximal Linear Feedback Shift Registers and generate pseudorandom bit sequences. This test uses the mutual information between the output and set of inputs which will be a random variable and its distribution is obeyed to an approximate $\{chi}^2$ -distribution. We adopt this statistic to a $\{chi}^2$ -test of independence by using contingency table. We also apply a proposed test to some non-linear crptosystems and show that this useful to evaluate the strength of the cryptosystems.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.17 no.3
• /
• pp.358-363
• /
• 2014

In this paper, we present two constructions of the attribute-based broadcast encryption(ABBE) algorithm. Attribute-based encryption(ABE) algorithm enables an access control mechanism over encrypted data by specifying access policies among private keys and ciphertexts. ABBE algorithm can be used to construct ABE algorithm with revocation mechanism. Revocation has a useful property that revocation can be done without affecting any non-revoked uers. The main difference between our algorithm and the classical ones derived from the complete subtree paradigm which is apt for military hierarchy. Our algorithm improve the efficiency from the previously best ABBE algorithm, in particular, our algorithm allows one to select or revoke users by sending ciphertext of constant size with respect to the number of attributes and by storing logarithm secret key size of the number of users. Therefore, our algorithm can be an option to applications where computation cost is a top priority and can be applied to military technologies in the near future.