• 정보보호학회논문지
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• 제31권3호
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• pp.533-544
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• 2021

양자적 특성을 활용한 Shor 알고리즘은 인수분해 및 이산대수 문제를 효율적으로 풀 수 있다. 이로 인해 RSA, 타원곡선(ECC: Elliptic Curve Cryptography) 등 인수분해와 이산대수 문제의 어려움에 기반하고 있는 기존 공개키 암호 시스템이 위협받고 있다. 이에 미국 국립표준기술연구소(NIST)에서는 양자 컴퓨터의 강력한 연산 능력에도 안전한 새로운 공개키 암호 체계의 표준인 양자 내성 암호(PQC: Post Quantum Cryptography)를 선정하는 공모를 진행하고 있다. 양자 내성 암호 후보군 중 다변수 이차식 기반 서명 기법은 짧은 서명 길이와 빠른 서명 및 검증으로 인해 사물인터넷(IoT) 등 제한된 자원을 갖는 기기에 적합하다. 이에 본 논문에서는 다변수 이차식 기반 서명 중 유일하게 3 라운드까지 최종 선정된 Rainbow에 대한 클래식 공격 기법과 양자적 특성을 이용한 공격 기법들을 분석하고, 현재 3라운드에 제시된 레인보우 파라미터에 대한 공격 복잡도를 계산하여 양자 내성 암호표준화 후보 알고리즘인 레인보우 서명기법이 제공하는 보안 강도를 분석한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.738-756
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• 2020

The modular multiplication is the key module of public-key cryptosystems such as RSA (Rivest-Shamir-Adleman) and ECC (Elliptic Curve Cryptography). However, the efficiency of the modular multiplication, especially the modular square, is very low. In order to reduce their operation cycles and power consumption, and improve the efficiency of the public-key cryptosystems, a dual-field efficient FIPS (Finely Integrated Product Scanning) modular multiplication algorithm is proposed. The algorithm makes a full use of the correlation of the data in the case of equal operands so as to avoid some redundant operations. The experimental results show that the operation speed of the modular square is increased by 23.8% compared to the traditional algorithm after the multiplication and addition operations are reduced about (s² - s) / 2, and the read operations are reduced about s² - s, where s = n / 32 for n-bit operands. In addition, since the algorithm supports the length scalable and dual-field modular multiplication, distinct applications focused on performance or cost could be satisfied by adjusting the relevant parameters.

• 한국정보처리학회논문지
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• 제6권1호
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• pp.122-133
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• 1999

TCP/Ip 기반하의네트워크 사용으로 많은 사용자들은 서로 정보를 공유하고 자원을 효율적으로 이용할 수 있게 되었다. 그러나 복잡해진 망 구조를 효율적으로 관리할 수 있는 프로토콜이 필요하게 되었다. 1989년 분산된 네트워크의 망 관리를 위하여 SNMP(Simple Network Management Protocol)가 표준으로 채택되었고 그후 보안 기능이 추가된 SNMPv2에서 제공하는암호화 방식은 대칭형 암호화 방식인 DES(Data Encryption Standard)와 인증 (Authentication)을 위한 MD5(Message Digest 5) 해쉬 함수이다. 그러나 DES는 키 길이의 취약성과 암호화 및 인증 알고리즘이 분리되어 수행되는 단범을 가진다. 이를 해결할 수 있는 방안으로 본 논문의 보안모듈에서는 RSA 공개키 방식을 사용한다. 본 논문은 SNMP와 관련된 사항들에 대해 고찰한 후, 표준 SNMPv3에서 제안하는 암호화 알고리즘 DES와 인증을 위한 MD5방식과 더불어 암호화와 인증을 동시에 수행할 수 있는 공개키 방식인 RSA를 적용함으로써 보안성을 강화하였다. 제안한 SNMPv3의 보안 모듈은 JAVA 언어로 구현하였으며 Windows NT 환경에서 실험되고 분석되었다.

• 대한수학회보
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• 제53권1호
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• pp.1-20
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• 2016

The general number field sieve (GNFS) is asymptotically the fastest known factoring algorithm. One of the most important steps of GNFS is to select a good polynomial pair. A standard way of polynomial selection (being used in factoring RSA challenge numbers) is to select a nonlinear polynomial for algebraic sieving and a linear polynomial for rational sieving. There is another method called a nonlinear method which selects two polynomials of the same degree greater than one. In this paper, we generalize Montgomery's method [12] using geometric progression (GP) (mod N) to construct a pair of nonlinear polynomials. We also introduce GP of length d + k with $1{\leq}k{\leq}d-1$ and show that we can construct polynomials of degree d having common root (mod N), where the number of such polynomials and the size of the coefficients can be precisely determined.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.824-827
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• 2003

With a rapid development of Information Telecommunication technique, network communication environment has been greatly improved. People come to feel more convinient to purchase products through Internet. Accordingly, various kinds of electronic payment systems have been developed and used. In this paper, we propose an algorithm which not only can associate the broker system with an electronic cash user, but also regenerate all amount of money previously paid using technique such as Meta-Message recovery and a RSA Blind Signature based on discrete logarithm problem.

• 호남수학학술지
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• 제28권2호
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• pp.185-196
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• 2006

A scheme based on the cryptography for enforcing multilevel security in a system where hierarchy is represented by a partially ordered set was first introduced by Akl et al. But the key generation algorithm of Akl et al. is infeasible when there is a large number of users. In 1985, MacKinnon et al. proposed a paper containing a condition which prevents cooperative attacks and optimizes the assignment in order to overcome this shortage. In 2005, Kim et al. proposed key management systems for multilevel security using one-way hash function, RSA algorithm, Poset dimension and Clifford semigroup in the context of modern cryptography. In particular, the key management system using Clifford semigroup of imaginary quadratic non-maximal orders is based on the fact that the computation of a key ideal $K_0$ from an ideal $EK_0$ seems to be difficult unless E is equivalent to O. We, in this paper, show that computing preimages under the bonding homomorphism is not difficult, and that the multilevel cryptosystem based on the Clifford semigroup is insecure and improper to the key management system.

• 한국정보보호학회:학술대회논문집
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• 한국정보보호학회 1995년도 종합학술발표회논문집
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• pp.126-137
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• 1995

VDM-SL(Vienna Development Method - Specification Language)은 다양한 표준들의 정확한 기술을 위해 제시되고 있는 형식규격어의 하나로서 특히 보안표준의 표현에 적합한 형식규격어이다. 이러한 VDM-SL을 사용하여 보안표준의 표현 및 실행코드 생성의 정확성과 편리성을 제공하기 위한 다양한 도구들이 개발되고 있으며 이들 중 IFAD VDM-SL Toolbox는 가장 많은 기능을 구진 도구이다. 본 논문에서는 IFAD WDM-SL Toolbox를 이용해 해쉬알고리즘의 하나인 MD4 Message Digest Algorithm을 형식적 표현기법으로 나타내고 이를 바탕으로 참조구현 코드를 C++로 생성하는 방법을 설명한다. 또한 형식적 표현기법과 IFAD VDM-SL Toolbox를 이용해 생성된 참조구현코드의 실행 결과를 MD4의 테스트 벡터 (test vector)를 이용하여 RSA사에서 구현한 MD4 알고리즘과 비교 분석하여 형식적 표현기법을 이용하여 생성된 코드의 활용성에 대해 설명하고자 한다.

• 한국정보보호학회:학술대회논문집
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• 한국정보보호학회 1995년도 종합학술발표회논문집
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• pp.163-172
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• 1995

In this paper, the bit-level 1-dimensionl systolic array for modular multiplication are designed. First of all, the parallel algorithms and data dependence graphs from Walter's Iwamura's methods based on Montgomery Algorithm for modular multiplication are derived and compared. Since Walter's method has the smaller computational index points in data dependence graph than Iwamura's, it is selected as the base algorithm. By the systematic procedure for systolic array design, four 1-dimensional systolic arrays ale obtained and then are evaluated by various criteria. Modifying the array derived from 〔0,1〕 projection direction by adding a control logic and serializing the communication paths of data A, optimal 1-dimensional systolic array is designed. It has constant I/O channels for modular expandable and is good for fault tolerance due to unidirectional paths. And so, it is suitable for RSA Cryptosystem which deals with the large size and many consecutive message blocks.

• 전자공학회논문지B
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• 제33B권9호
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• pp.62-69
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• 1996

In this paper, the bit-level 1-dimensional systolic array for modular multiplication is designed. First of all, the parallel algorithm and data dependence graph from walter's method based on montgomery algorithm suitable for array design for modular multiplication is derived. By the systematic procedure for systolic array design, four 1-dimensional systolic arrays are obtained and then are evaluated by various criteria. As it is modified the array which is derived form [0,1] projection direction by adding a control logic and it is serialized the communication paths of data A, optimal 1-dimensional systolic array is designed. It has constant I/O channels for expansile module and it is easy for fault tolerance due to unidirectional paths. It is suitable for RSA cryptosystem which deals iwth the large size and many consecutive message blocks.

• 정보보호학회논문지
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• 제12권1호
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• pp.43-54
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• 2002

McEliece introduced a public-key cryptosystem based on Algebraic codes, specially binary classical Goppa which have a good decoding algorithm and vast number of inequivalent codes with given parameters. And the advantage of this system low cost of their encryption and decryption procedures compared with other public-key systems specially RSA, ECC based on DLP(discrete logarithm problem). But in [1], they resent new attack based on probabilistic algorithm to find minimum weight codeword, so for a sufficient security level, much larger parameter size [2048, 1608,81]is required. Then the big size of public key make McEliece PKC more inefficient. So in this paper, we will propose New Type PKC using q-ary Hyperelliptic code so that with smaller parameter(1 over 3) but still work factor as hi인 as McEliece PKC and faster encryption, decryption can be maintained.