• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.351-353
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• 1999

본 논문에서는 기존의 브로드캐스트 암호화 방식에 대한 고찰과 현재까지의 기술들의 단점을 보완할 수 있는 새로운 브로드캐스트 채널 상에서 특정 사용자만이 정보를 사용할 수 있도록 하기 위한 프로토콜이다. 이러한 시스템을 평가하는 중요한 비교 변수로는 전송량과 사용자가 보관하고 있어야 하는 해독키의 크기이다. 본 논문에서는 사용자를 일정 그룹으로 나누어서 암호키를 할당함으로써 사용자 개개인에게 암호키를 할당하는 경우 보다 전송량을 줄일 수 있었고, 메시지는 하나의 세션키로 암화화하고 이 세션키를 다시 암호화하여 메시지의 헤더에 첨가하여 전달함으로써 전송량을 확실히 줄일 수 있었다. 사용자를 임의의 그룹으로 구성하여 하나의 그룹에 일정수 이상이 정보를 전달받을 자격이 있다면 그 그룹의 암호키를 선택하여 세션키를 암호화하였다. 이 때 그룹에 있는 권한이 없는 사용자들이 정보를 전달받을 수 있으나, 이들의 크기는 실험 결과 그다지 문제가 되지 않을 정도로 작은 수임을 알 수 있었다.

• Review of KIISC
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• v.32 no.1
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• pp.47-56
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• 2022

NIST는 PQC Round 3 평가 기준으로 부채널 분석 및 오류 주입에 대한 안전성을 역설함에 따라 Round 3 양자내성암호에 대한 새로운 부채널 공격 시나리오 및 대응 기법이 빠르게 제시되고 있다. 따라서 각 방법론의 동향을 파악하고 재정의, 분류하는 작업이 필수적으로 요구된다. 본 논문에서는 NIST PQC Round 3 최종 후보 중 격자 기반 암호 KEM(SABER, CRYSTALS-KYBER, NTRU)에 대한 부채널 분석기법 및 대응기술 동향을 조사 및 분석하고 향후 Round 3 격자 기반 KEM 알고리즘의 부채널 연구 전망을 논의한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.2
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• pp.45-58
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• 2001

There are relatively many research results of the validation of the cryptography. But few researches on the validation of cryptography implementations were accomplished. However, developer\`s misunderstanding the crypto-algorithm or a mistake in implementation of the crypto-a1gorithm leads to lose reliability of security products. Therefore, as validation of the crypto-algorithm itself also validation of the implementation is important. The major objective of this paper is to propose Security Products Validation Tool. Our tool validates implementation of the public key algorithm (RSA. KCDSA) and hash algorithm (SHA-1, HAS-170). The validation process is composed of several items and our tool performs validation teats for conformance to related standard.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.3
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• pp.323-330
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• 2021

Recently, the advantages of high-speed arithmetic in quantum computers have been known, and interest in quantum circuits utilizing qubits has increased. The Grover algorithm is a quantum algorithm that can reduce n-bit security level symmetric key cryptography and hash functions to n/2-bit security level. Since the Grover algorithm work on quantum computers, the symmetric cryptographic technique and hash function to be applied must be implemented in a quantum circuit. This is the motivation for these studies, and recently, research on implementing symmetric cryptographic technique and hash functions in quantum circuits has been actively conducted. However, at present, in a situation where the number of qubits is limited, we are interested in implementing with the minimum number of qubits and aim for efficient implementation. In this paper, the domestic hash function LSH is efficiently implemented using qubits recycling and pre-computation. Also, major operations such as Mix and Final were efficiently implemented as quantum circuits using ProjectQ, a quantum programming tool provided by IBM, and the quantum resources required for this were evaluated.

• Review of KIISC
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• v.5 no.1
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• pp.73-84
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• 1995

본 논문에서는 국내 정보보호 체계를 수립하기 위하여 외국에서의 정보보호 체계분석의 일환으로 영국의 정보보호 시스템 평사승인 체계에 대하여 분석하였다. 먼저 영국에서의 정보기관 구조를 소개하고, 정보보호 체계와 관련한 조직의 구성 및 임무에 대하여 기술하였다. 또한 영국의 정보보호 시스템 평가승인 절차를 분석하였으며 영국의 암호 알고리즘과 평가 기준서인ITSEC에 대해 분석하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1439-1444
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• 2013

Recently, as the use of the applications like online banking and stock trading is increasing by the rapid development of the network, security of data content is becoming more and more important. Accordingly, public key or symmetric key encryption algorithm is widely used in open networks such as the internet for the protection of data. Generally, public key cryptographic systems is based on two famous number theoretic problems namely factoring or discrete logarithm problem. So, public key cryptographic systems is relatively slow compared to symmetric key cryptography systems. Among public key cryptographic systems, the advantage of ECC compared to RSA is that it offers equal security for a far smaller key. For this reason, ECC is faster than RSA. In this paper, we propose a efficient key generation method for elliptic curve cryptography system based on the real number field.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.1
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• pp.17-28
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• 2019

In the financial investment management strategy, the distributed investment selecting and combining various financial assets is called portfolio management theory. In recent years, the blockchain based financial assets, such as cryptocurrencies, have been traded on several well-known exchanges, and an efficient portfolio management approach is required in order for investors to steadily raise their return on investment in cryptocurrencies. On the other hand, deep learning has shown remarkable results in various fields, and research on application of deep reinforcement learning algorithm to portfolio management has begun. In this paper, we propose an efficient financial portfolio investment management method based on Asynchronous Advantage Actor-Critic (A3C), which is a representative asynchronous reinforcement learning algorithm. In addition, since the conventional cross-entropy function can not be applied to portfolio management, we propose a proper method where the existing cross-entropy is modified to fit the portfolio investment method. Finally, we compare the proposed A3C model with the existing reinforcement learning based cryptography portfolio investment algorithm, and prove that the performance of the proposed A3C model is better than the existing one.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.6
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• pp.29-36
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• 2005

RFID(Radio Frequency Identification) will be used for recognizing things and offering distinctive information in Ubiquitous environment. But we are not ready to provide security service to RFID. Therefore we propose the approach of safe RFID system which provides the solution for eavesdrop, forgery, and modification based on Pre-Distribution protocol and RC5 security algorithm. First We distributes the secret key to the Tag with the Reader that is major subject on RFID system using Pre-Distribution protocol. Then we will provide to various security services and privacy protection using RC5 security algorithm. The proposed safe RFID system simulated on ATmega128 evaluate environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.4
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• pp.585-592
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• 2014

In this paper, we study the LEA[1] block cipher system in UICC-16bit only. Also, we explain a key-schedule function and encryption/decryption structures, propose an advanced modified key-scheduling, and perform LEA in UICC-16bit that we proposed advanced modified key-scheduling. Also, we compare LEA with ARIA that proposed domestic standard block cipher, and we evaluate the efficiency on the LEA algorithm.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.1
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• pp.28-38
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• 2007

In this paper, we implement Microsoft COM software modules for elliptic curve cryptographic applications and analyze its performance. The implemented COM software modules support all elliptic curve key exchange protocols and elliptic curve digital signature algorithm in IEEE 1363 finite fields GF(p) and GF(2m). Since the implemented software modules intend to focus on a component-based software development method, and thus it have a higher productivity and take systematic characteristics to be open outward and to be standardized. Accordingly, it enable a software to be developed easier and faster rather than a method using C library. In addition it support the Microsoft COM interface, we can easily implement secure software applications based on elliptic curve cryptographic algorithms.