• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.32 no.6
• /
• pp.1127-1137
• /
• 2022

Cryptographic analysis and decryption technology utilizing the parallel operation of GPU has been studied in the direction of shortening the computation time of the password analysis system. These studies focus on optimizing the code to improve the speed of cryptographic analysis operations on a single GPU or simply increasing the number of GPUs to enhance parallel operations. However, using a large number of GPUs without optimization for data transmission causes longer data transmission latency than using a single GPU and increases the overall computation time of the cryptographic analysis system. In this paper, we investigate GPUDirect RDMA and related technologies for high-performance data processing in deep learning or HPC research fields in GPU clustering environments. In addition, we present a method of designing a high-performance cryptanalysis system using the relevant technologies. Furthermore, based on the suggested system topology, we present a method of implementing a cryptanalysis system using password cracking and GPU reduction. Finally, the performance evaluation results are presented according to demonstration of high-performance technology is applied to the implemented cryptanalysis system, and the expected effects of the proposed system design are shown.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.13 no.1
• /
• pp.139-146
• /
• 2003

In this paper we demonstrate a cryptanalysis of the stream cipher LILI-128. Our approach to analysis on LILI-128 is to solve an overdefined system of multivariate equations. The LILI-128 keystream generato $r^{[8]}$ is a LFSR-based synchronous stream cipher with 128 bit key. This cipher consists of two parts, “CLOCK CONTROL”, pan and “DATA GENERATION”, part. We focus on the “DATA GENERATION”part. This part uses the function $f_d$. that satisfies the third order of correlation immunity, high nonlinearity and balancedness. But, this function does not have highly nonlinear order(i.e. high degree in its algebraic normal form). We use this property of the function $f_d$. We reduced the problem of recovering the secret key of LILI-128 to the problem of solving a largely overdefined system of multivariate equations of degree K=6. In our best version of the XL-based cryptanalysis we have the parameter D=7. Our fastest cryptanalysis of LILI-128 requires $2^{110.7}$ CPU clocks. This complexity can be achieved using only $2^{26.3}$ keystream bits.

• ETRI Journal
• /
• v.35 no.1
• /
• pp.131-141
• /
• 2013

Integral cryptanalysis, which is based on the existence of (higher-order) integral distinguishers, is a powerful cryptographic method that can be used to evaluate the security of modern block ciphers. In this paper, we focus on substitution-permutation network (SPN) ciphers and propose a criterion to characterize how an r-round integral distinguisher can be extended to an (r+1)-round higher-order integral distinguisher. This criterion, which builds a link between integrals and higher-order integrals of SPN ciphers, is in fact based on the theory of direct decomposition of a linear space defined by the linear mapping of the cipher. It can be directly utilized to unify the procedure for finding 4-round higher-order integral distinguishers of AES and ARIA and can be further extended to analyze higher-order integral distinguishers of various block cipher structures. We hope that the criterion presented in this paper will benefit the cryptanalysts and may thus lead to better cryptanalytic results.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.6
• /
• pp.1565-1575
• /
• 1997

A new encryption algorithm had been proposed as a replacement to the Data Encryption Standard (DES) in [1,2]. It called the Extended DES (EDES) has a key length of 112 bits. The plaintext data consists of 96 bits divided into 3 sub-blocks of 32 bits each. The EDES has a potentially higher resistance to differential cryptanalysis that the DES due to the asymmetric number of f functions performed on each of the 3 sub-blocks and due to the increase of S-boxes from 8 to 16. This paper propose a hardware design for the EDES and its implementation in VLSI. The VLSI chip implements data encryption and decryption in a single hardware unit. With a system clock frequency of 15Mhz the device permits a data conversion rate of about 90Mbit/sec. Therefore, the chip can be applied to on-line encryption in high-speed networking protocols.

• Journal of Digital Convergence
• /
• v.17 no.2
• /
• pp.187-194
• /
• 2019

A security company has been proposed for various healthcare systems. However, there are improvements in order to achieve better efficiency and stability in the various protocols presented. The purpose of this paper is to provide cryptanalysis and solution on Vijayakumar et al.'s secure communication scheme for healthcare system using wearable devices. Especially, it is weak against denial of service attack and it does not provide integrity of the transmitted messages. Thereby, this paper proposes a new secure communication scheme to cope from the problems in Vijayakumar et al.'s scheme. It provides authentication and integrity, which could be the security solution against Vijayakumar et al.'s scheme. Furthermore, it also provides a good computational overhead compared to Vijayakumar et al.'s scheme.

• Journal of Internet Computing and Services
• /
• v.7 no.1
• /
• pp.59-64
• /
• 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.

• Journal of information and communication convergence engineering
• /
• v.9 no.6
• /
• pp.683-688
• /
• 2011

The wireless sensor network (WSN) is well known for an enabling technology for the ubiquitous environment such as real-time surveillance system, habitat monitoring, home automation and healthcare applications. However, the WSN featuring wireless communication through air, a resource constraints device and irregular network topology, is threatened by malicious nodes such as eavesdropping, forgery, illegal modification or denial of services. For this reason, security in the WSN is key factor for utilizing the sensor network into the commercial way. There is a series of symmetric cryptography proposed by laboratory or industry for a long time. Among of them, recently proposed HUMMINGBIRD algorithm, motivated by the design of the well-known Enigma machine, is much more suitable to resource constrained devices, including smart card, sensor node and RFID tags in terms of computational complexity and block size. It also provides resistance to the most common attacks such as linear and differential cryptanalysis. In this paper, we implements ultra-lightweight cryptography, HUMMINGBIRD algorithm into the resource constrained device, sensor node as a perfectly customized design of sensor node.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.06d
• /
• pp.109-114
• /
• 2007

RFID 기술은 유비쿼터스 환경의 편리성을 위한 목적을 쉽게 이룰 수 있는 기술로 현재 주목 받고 있으며 많은 장점을 가지고 있다. 이러한 RFID 환경에서 가장 보안적인 문제를 갖는 것은 RFID 태그에 저장 관리되어지는 식별 정보에 대한 프라이버시 침해 문제의 보호이다. 본 논문에서는 정형검증 방법인 모델 체킹을 이용하여 RFID 태그와 리더기간의 상호 인증 및 태그의 식별 정보에 대한 안전성을 분석하기 위해 RFID 보안 프로토콜의 취약성 분석 및 수정된 프로토콜을 제안함으로써 안전한 유비쿼터스 네트워크 환경을 구축하고자 한다.

• Journal of the Optical Society of Korea
• /
• v.20 no.1
• /
• pp.55-63
• /
• 2016

In this paper, a new asymmetric public key cryptography based on the modified RSA algorithm is proposed by using logic-based optical processing. The proposed asymmetric public key algorithm is realized into an optical schematic, where AND, OR and XOR logic operations are implemented by using free space digital optics architecture. Schematically, the proposed optical configuration has an advantage of generating the public keys simultaneously. Another advantage is that the suggested optical setup can also be used for message encryption and decryption by simply replacing data inputs of SLMs in the optical configuration. The last merit is that the optical configuration has a 2-D array data format which can increase the key length easily. This can provide longer 2-D key length resulting in a higher security cryptosystem than the conventional 1-D key length cryptosystem. Results of numerical simulation and differential cryptanalysis are presented to verify that the proposed method shows the effectiveness in the optical asymmetric cryptographic system.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.18 no.5
• /
• pp.195-199
• /
• 2008

We present an attack which forges a credential without the help of the credential issuer in the protocol designed by Nakazato, Wang and Yamamura at ASIAN 2007 The attack avoids using the credential issuer's private key by taking advantage of the property of bilinear pairing. Implication of this collusion attack by user and verifiers also discussed.