• Title/Summary/Keyword: RSA public key

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Efficient and Dynamic Authenticated Dictionary Design Using RSA One-way Accumulator (RSA 일방향 어큐뮬레이터를 이용한 효율적이고 동적인 인증 딕셔너리 설계)

  • Kim, Soon-Seok;Lee, Yong-Hee;Lee, Kang-Woo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.4
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    • pp.651-660
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    • 2008
  • The widespread use of public networks, such as the Internet, for the exchange of sensitive data that need a severe security, like legally valid documents and business transactions. At the same time public-key certificates used for sensitive data interchange form the viewpoint of data integrity and authentication. But there are some weakness of data transfer capacity and security in public key infrastructure(PKI) environment. This paper use the RSA one-way accumulator to realize an efficient and dynamic authenticated dictionary, where untrusted directories provide cryptographically verifiable answers to membership queries on a set maintained by a trusted source.

FPGA Implementation of RSA Public-Key Cryptographic Coprocessor for Restricted System

  • Kim, Mooseop;Park, Yongje;Kim, Howon
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1551-1554
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    • 2002
  • In this paper, the hardware implementation of the RSA public-key cryptographic algorithm is presented. The RSA cryptographic algorithm is depends on the computation of repeated modular exponentials. The Montgomery algorithm is used and modified to reduce hardware resources and to achieve reasonable operating speed for smart card. An efficient architecture for modular multiplications based on the array multiplier is proposed. We have implemented a 10240it RSA cryptographic processor based on proposed scheme in IESA system developed for smart card emulating system. As a result, it is shown that proposed architecture contributes to small area and reasonable speed for smart cards.

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Proposal for Analog Signature Scheme Based on RSA Digital Signature Algorithm and Phase-shifting Digital Holography

  • Gil, Sang Keun
    • Current Optics and Photonics
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    • v.4 no.6
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    • pp.483-499
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    • 2020
  • In this paper, a novel analog signature scheme is proposed by modifying an RSA-based digital signature scheme with optical phase-shifting digital holography. The purpose of the proposed method is generating an analog signature to provide data confidentiality and security during the data transfer, compared to the digital signature. The holographic encryption technique applied to a hash value reveals an analog-type of pseudo-random pattern in the analog signature scheme. The public key and secret key needed to verify the analog signature are computed from public key ciphers which are generated by the same holographic encryption. The proposed analog signature scheme contains a kind of double encryption in the process of generating signature and key, which enhances security level more than the digital signature. The results of performance simulations show the feasibility of the highly secure signature scheme, and security analysis shows high robustness against known-message attacks and chosen-message attacks. In addition, the proposed method can apply to one-time signature schemes which can be used to sign only one message and it can also apply to authentication, e-mails, electronic banking and electronic data interchange.

Design of RSA cryptographic circuit for small chip area using refined Montgomery algorithm (개선된 몽고메리 알고리즘을 이용한 저면적용 RSA 암호 회로 설계)

  • 김무섭;최용제;김호원;정교일
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.12 no.5
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    • pp.95-105
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    • 2002
  • This paper describes an efficient method to implement a hardware circuit of RSA public key cryptographic algorithm, which is important to public-key cryptographic system for an authentication, a key exchange and a digital signature. The RSA algorithm needs a modular exponential for its cryptographic operation, and the modular exponential operation is consists of repeated modular multiplication. In a numerous algorithm to compute a modular multiplication, the Montgomery algorithm is one of the most widely used algorithms for its conspicuous efficiency on hardware implementation. Over the past a few decades a considerable number of studies have been conducted on the efficient hardware design of modular multiplication for RSA cryptographic system. But many of those studies focused on the decrease of operating time for its higher performance. The most important thing to design a hardware circuit, which has a limit on a circuit area, is a trade off between a small circuit area and a feasible operating time. For these reasons, we modified the Montgomery algorithm for its efficient hardware structure for a system having a limit in its circuit area and implemented the refined algorithm in the IESA system developed for ETRI's smart card emulating system.

PARTIAL KEY EXPOSURE ATTACKS ON RSA AND ITS VARIANT BY GUESSING A FEW BITS OF ONE OF THE PRIME FACTORS

  • Sarkar, Santanu;Maitra, Subhamoy
    • Bulletin of the Korean Mathematical Society
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    • v.46 no.4
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    • pp.721-741
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    • 2009
  • Consider RSA with N = pq, q < p < 2q, public encryption exponent e and private decryption exponent d. We first study cryptanalysis of RSA when certain amount of the Most Significant Bits (MSBs) or Least Significant Bits (LSBs) of d is known. The basic lattice based technique is similar to that of Ernst et al. in Eurocrypt 2005. However, our idea of guessing a few MSBs of the secret prime p substantially reduces the requirement of MSBs or LSBs of d for the key exposure attack. Further, we consider the RSA variant proposed by Sun and Yang in PKC 2005 and show that the partial key exposure attack works significantly on this variant.

A Study on the Secure Global Key Recovery System (안전한 글로벌 키복구 시스템에 관한 연구)

  • Yang Hyung-Kyu;An Young-Hwa
    • Journal of Internet Computing and Services
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    • v.7 no.1
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    • pp.59-64
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    • 2006
  • Harn al proposed a GKRS(Global Key Recovery System) that combines the functions of the key recovery authorities and the public key certification authorities(CA), Among other features, user dominance(i.e, a user is allowed to select his own public-private key pair and especially a public element for verifying the validity of the public-private key pair)is proposed by [1] for wide acceptance of GKRS. In this paper, we attack the RSA version of GKRS by showing that its user-dominance feature and the corresponding key verification scheme employed by the CA allow for fraud by users against CA. We propose more secure GKPS than original GKPS, The proposed system makes the probability of user fraud negligible small.

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Implementation of Modular Multiplication and Communication Adaptor for Public Key Crytosystem (공개키 암호체계를 위한 Modular 곱셈개선과 통신회로 구현에 관한 연구)

  • 한선경;이선복;유영갑
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.7
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    • pp.651-662
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    • 1991
  • An improved modular multiplication algorithm for RSA type public key cryptosystem and its application to a serial communication cricuit are presented. Correction on a published fast modular multiplication algorithm is proposed and verified thru simulation. Cryptosystem for RS 232C communication protocol isdesigned and prototyped for low speed data exchange between computers. The system adops the correct algoroithm and operates successfully using a small size key.

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The Improved Estimation of the Least Upper Bound to Search for RSA's Private key

  • Somsuk, Kritsanapong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.6
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    • pp.2074-2093
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    • 2022
  • RSA is known as one of the best techniques for securing secret information across an unsecured network. The private key which is one of private parameters is the aim for attackers. However, it is exceedingly impossible to derive this value without disclosing all unknown parameters. In fact, many methods to recover the private key were proposed, the performance of each algorithm is acceptable for the different cases. For example, Wiener's attack is extremely efficient when the private key is very small. On the other hand, Fermat's factoring can quickly break RSA when the difference between two large prime factors of the modulus is relatively small. In general, if all private parameters are not disclosed, attackers will be able to confirm that the private key is unquestionably inside the scope [3, n - 2], where n is the modulus. However, this scope has already been reduced by increasing the greatest lower bound to [dil, n - 2], where dil ≥ 3. The aim of this paper is to decrease the least upper bound to narrow the scope that the private key will remain within this boundary. After finishing the proposed method, the new scope of the private key can be allocated as [dil, dir], where dir ≤ n - 2. In fact, if the private key is extremely close to the new greatest lower bound, it can be retrieved quickly by performing a brute force attack, in which dir is decreased until it is equal to the private key. The experimental results indicate that the proposed method is extremely effective when the difference between prime factors is close to each other and one of two following requirement holds: the first condition is that the multiplier of Euler totient function is very close to the public key's small value whereas the second condition is that the public key should be large whenever the multiplier is far enough.

A Study on the Performance Evaluation of Elliptic Curve Cryptography based on a Real Number Field (실수체 기반 타원곡선 암호의 성능 평가에 관한 연구)

  • Woo, Chan-Il;Goo, Eun-Hee;Lee, Seung-Dae
    • 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.

Efficient RSA-Based PAKE Procotol for Low-Power Devices (저전력 장비에 적합한 효율적인 RSA 기반의 PAKE 프로토콜)

  • Lee, Se-Won;Youn, Taek-Young;Park, Yung-Ho;Hong, Seok-Hie
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.6
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    • pp.23-35
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    • 2009
  • Password-Authenticated Key Exchange (PAKE) Protocol is a useful tool for secure communication conducted over open networks without sharing a common secret key or assuming the existence of the public key infrastructure (PKI). It seems difficult to design efficient PAKE protocols using RSA, and thus many PAKE protocols are designed based on the Diffie-Hellman key exchange (DH-PAKE). Therefore it is important to design an efficient PAKE based on RSA function since the function is suitable for designing a PAKE protocol for imbalanced communication environment. In this paper, we propose a computationally-efficient key exchange protocol based on the RSA function that is suitable for low-power devices in imbalanced environment. Our protocol is more efficient than previous RSA-PAKE protocols, required theoretical computation and experiment time in the same environment. Our protocol can provide that it is more 84% efficiency key exchange than secure and the most efficient RSA-PAKE protocol CEPEK. We can improve the performance of our protocol by computing some costly operations in offline step. We prove the security of our protocol under firmly formalized security model in the random oracle model.