• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.2
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• pp.261-270
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• 2015

In information security devices, such as Smart Cards, vulnerabilities of the RSA algorithm which is used to protect the data were found in the Side Channel Analysis. The RSA is especially vulnerable to Power Analysis which uses power consumption when the algorithm is working. Typically Power Analysis is divided into SPA(Simple Power Analysis) and DPA(Differential Power Analysis). On top of this, there is a CA(Collision Analysis) which is a very powerful attack. CA makes it possible to attack using a single waveform, even if the algorithm is designed to secure against SPA and DPA. So Message blinding, which applies the window method, was considered as a countermeasure. But, this method does not provide sufficient safety when the window size is small. Therefore, in this paper, we propose a new countermeasure that provides higher safety against CA. Our countermeasure is a combination of message and exponent blinding which is applied to the window method. In addition, through experiments, we have shown that our countermeasure provides approximately 124% higher attack complexity when the window size is small. Thus it can provide higher safety against CA.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.155-160
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• 2010

Since the RSA cryptosystem based on Chinese Remainder Theorem is vulnerable to many fault insertion attacks, some countermeasures against them were proposed. Recently, Kim et al. or Ha et al. respectively proposed each countermeasure scheme based on fault propagation method. Unfortunately, Hur et al. insist that these countermeasures are vulnerable to their opcode modification fault attack. In this paper, we show that the proposed attack can not apply to almost CRT-RSA countermeasures which use multi-precision operations in long bit computation. Therefore, the countermeasure against fault attack proposed by Kim et al. or Ha et al. are still secure.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.4
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• pp.51-57
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• 2003

The development of the communication network and the other network method can generate serious social problems. So, it is highly required to control security of network. These problems related security will be developed and keep up to confront with anti-security field such as hacking, cracking. The way to preserve security from hacker or cracker without developing new cryptographic algorithm is keeping the state of anti-cryptanalysis in a prescribed time by means of extending key-length. In this paper, we proposed M3 algorithm for the reduced processing time in the montgomery multiplication part. Proposed M3 algorithm using the matrix function M(.) and lookup table perform optionally montgomery multiplication with repeated operation. In this result, modified repeated operation part produce 30% processing rate than existed montgomery multiplicator. The proposed montgomery multiplication structured unit array method in carry generated part and variable length multiplication for eliminating bottle neck effect with the RSA cryptosystem. Therefore, this proposed montgomery multiplier enforce the real time processing and prevent outer cracking.

• 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.

• Review of KIISC
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• v.2 no.3
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• pp.102-107
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• 1992

• Review of KIISC
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• v.33 no.2
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• pp.13-20
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• 2023

양자 알고리즘이 구동 가능한 양자 컴퓨터는 현대 암호들이 기반하고 있는 수학적 난제들을 빠르게 해결할 수 있다, 대칭키 암호의 경우, Grover 알고리즘을 사용한 전수조사 가속화가 가능하며, 공개키 암호의 경우, Shor 알고리즘을 사용하여 RSA와 ECC가 기반하고 있는 난제들을 다항시간 내에 해결할 수 있다. 이에 다양한 대칭키 암호, 그리고 RSA와 ECC의 양자 해킹 방법론에 대한 연구들이 수행되고 있다. 물론 양자컴퓨터의 제한적인 성능으로 인해 실제 해킹이 가능한 수준은 아니지만, 양자 공격 회로를 제시하고 그에 필요한 양자 자원들을 분석하는 방식으로 실제 해킹 가능성에 대해 추정해 보는 연구 결과들이 발표되고 있다. 이에 본 기고에서는 양자 컴퓨터를 통한 대칭키 및 공개키 암호 해킹 동향에 대해 살펴보고자 한다.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.6
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• pp.301-309
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• 2001

본 논문에서는 RSA 암호 시스템의 핵심 과정인 모듈로 멱승 연산에 대한 새로운 하드웨어 구조를 제시한다. 본 방식은 몽고메리 곱셈 알고리즘을 사용하였으며 기존의 방법들이 데이터 종속 그래프(DG : Dependence Graph)를 수직으로 매핑한 것과는 달리 여기서는 수평으로 매핑하여 1차원 선형 어레이구조를 구성하였다. 그 결과로 멱승시에 중간 결과값이 순차적으로 나와서 바로 다음 곱셈을 위한 입력으로 들어갈 수 있기 때문에 100%의 처리율(throughput)을 이룰 수 있고, 수직 매핑 방식에 비해 절반의 클럭 횟수로 연산을 해낼 수 있으며 컨트롤 또한 단순해지는 장점을 가진다. 각 PE(Processing Element)는 2개의 전가산기와 3개의 멀티플렉서로 이루어져 있고, 암호키의 비트수를 k비트라 할 때 k+3개의 PE만으로 파이프라인구조를 구현하였다. 1024비트 RSA데이터의 암호 똔느 복호를 완료하는데 2k$^2$+12k+19의 클럭 수가 소요되며 클럭 주파수 100Mhz에서 약 50kbps의 성능을 보인다. 또한, 제안된 하드웨어는 내부 계산 구조의 지역성(locality), 규칙성(regularity) 및 모듈성(modularity) 등으로 인해 실시간 고속 처리를 위한 VLSI 구현에 적합하다.

• Journal of the Korea Society of Computer and Information
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• v.6 no.3
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• pp.84-90
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• 2001

The development of network and the other communication-network can generate serious problems. So, it is highly required to control security of network. These problems related secu be developed and keep up to confront with anti-security part such as hacking, cracking. Th way to preserve security from hacker or cracker without developing new cryptographic algori keeping the state of anti-cryptanalysis in a prescribed time by means of extending key-length In this paper, the proposed montgomery multiplication structured unit array method in carry generated part and variable length multiplicator for eliminating bottle neck effect with the RSA cryptosystem. Therefore, this proposed montgomery multiplicator enforce the real time processing and prevent outer cracking.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.878-883
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• 2020

Cryptographic algorithms are used to prevent the illegal manipulation of data. They are divided into public-key cryptosystems and symmetric-key cryptosystems. Public-key cryptosystems require considerable time for encryption and decryption compared to symmetric-key cryptosystem. On the other hand, key management, and delivery are easier for public-key cryptosystems than symmetric-key cryptosystems because different keys are used for encryption and decryption. Furthermore, hash functions are being used very effectively to verify the integrity of the digital content, as they always generate output with a fixed size using the data of various sizes as input. This paper proposes a method using RSA public-key cryptography and a hash function to determine if a digital image is deformed or not and to detect the manipulated location. In the proposed method, the entire image is divided into several blocks, 64×64 in size. The watermark is then allocated to each block to verify the deformation of the data. When deformation occurs, the manipulated pixel will be divided into smaller 4×4 sub-blocks, and each block will have a watermark to detect the location. The safety of the proposed method depends on the security of the cryptographic algorithm and the hash function.

• Review of KIISC
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• v.32 no.1
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• pp.19-29
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• 2022

2011 Jao와 De Feo에 의해 제안된 SIDH가 기존 타원곡선 사이의 isogeny를 이용한 암호보다 효율적인 성능을 제공하고, 그 후 2016년 Costello 등의 효율적인 연산 방법으로 SIDH 속도가 3배 이상 향상되면서, 타원곡선 사이의 isogeny를 이용한 암호가 양자 컴퓨팅 환경에서 RSA와 ECC를 대체할 암호로 주목을 받기 시작했다. 특히 isogeny 기반 암호는 다른 PQC 암호에 비해 작은 키 사이즈를 제공한다는 장점으로 현재까지 활발히 연구가 진행되고 있으며, SIDH를 기반으로 둔 SIKE는 NIST PQC 표준화 공모전 Round 3의 대체 후보이다. 다른 PQC 암호에 비해 속도가 느리다는 점이 isogeny 기반 암호의 단점인 만큼, isogeny 기반 암호는 처음 제안된 후 10년 동안 최적화를 중심으로 큰 발전을 이뤄왔다. 본 논문에서는 isogeny 기반 암호의 최신 연구 동향을 소개한다.