• Journal of the Korean Data and Information Science Society
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• v.9 no.2
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• pp.237-246
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• 1998

We put the pseudo-random number generator into catagories like MiCG, MuCG, URG, ICG, EICG, and test uniformity and independency by 10,000 times through n empirical trial after selecting this random number generator. Here, from a fraction of data(20, 40, 60, 80, 100) with a significance level of 0.1, 0.05 and 0.01, we drive cumulative frequency with K-S, $X^{2}$, poker, run, autocorrelation test. As a result from the uniformity and independency among five random number generators based on all these data, all random number generator except EICG passed uniformity and independency test, and the URG turn out to be excellent in periodicity.

• Convergence Security Journal
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• v.12 no.4
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• pp.17-23
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• 2012

Recently, the research for cryptographic algorithm, in particular, a stream cipher has been actively conducted for wireless devices as growing use of wireless devices such as smartphone and tablet. LFSR based random number generator is widely used in stream cipher since it has simple architecture and it operates very fast. However, the conventional multi-LFSR RNG (random number generator) suffers from its hardware complexity as well as very closed correlation between the numbers generated. A leap-ahead LFSR was presented to solve these problems. However, it has another disadvantage that the maximum period of the generated random numbers are significantly decreased according to the relationship between the number of the stages of the LFSR and the number of the output bits of the RNG. This paper presents new leap-ahead LFSR architecture to prevent this decrease in the maximum period by applying segmentation technique to the conventional leap-ahead LFSR. The proposed architecture is implemented using VHDL and it is simulated in FPGA using Xilinx ISE 10.1, with a device Virtex 4, XC4VLX15. From the simulation results, the proposed architecture has only 20% hardware complexity but it can increases the maximum period of the generated random numbers by 40% compared to the conventional Leap-ahead archtecture.

• Journal of IKEEE
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• v.24 no.1
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• pp.52-58
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• 2020

This paper describes a hardware implementation of a true random number generator (TRNG) for information security applications. A new approach for TRNG design was proposed by adopting random transition rules in cellular automata and applying different transition rules at every time step. The TRNG circuit was implemented on Spartan-6 FPGA device, and its hardware operation generating random data with 100 MHz clock frequency was verified. For the random data of 2×10⁷ bits extracted from the TRNG circuit implemented in FPGA device, the randomness characteristics of the generated random data was evaluated by the NIST SP 800-22 test suite, and all of the fifteen test items were found to meet the criteria. The TRNG in this paper was implemented with 139 slices of Spartan-6 FPGA device, and it offers 600 Mbps of the true random number generation with 100 MHz clock frequency.

• Convergence Security Journal
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• v.20 no.2
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• pp.69-76
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• 2020

Blockchain 2.0 supports programmable smart contract for the various distributed application. However, the environment of running smart contract is limited in the blockchain, so the smart contract only get the deterministic information, such as block height, block hash, and so on. Therefore, some applications, which requires random information, such as lottery or batting, should use oracle service that supply the information outside of blockchain. This paper develops a random number generator oracle service. The random number generator oracle service use irregular big data as entropy source. This paper tests the randomness of bits sequence generated from oracle service using NIST SP800-22. This paper also describes the advantages of irregular big data in our model in perspective of cost comparing hardware entropy source.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2240-2250
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• 2016

MIFARE Classic is the most popular contactless smart card, which is primarily used in the management of access control and public transport payment systems. It has several security features such as the proprietary stream cipher Crypto 1, a challenge-response mutual authentication protocol, and a random number generator. Unfortunately, multiple studies have reported structural flaws in its security features. Furthermore, various attack methods that target genuine MIFARE Classic cards or readers have been proposed to crack the card. From a practical perspective, these attacks can be partitioned according to the attacker's ability. However, this measure is insufficient to determine the optimal attack flow due to the refined random number generator. Most card-only attack methods assume a predicted or fixed random number, whereas several commercial cards use unpredictable and unfixable random numbers. In this paper, we propose optimal MIFARE Classic attack procedures with regards to the type of random number generator, as well as an adversary's ability. In addition, we show actual attack results from our portable experimental setup, which is comprised of a commercially developed attack device, a smartphone, and our own application retrieving secret data and sector key.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.3
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• pp.365-378
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• 2024

The operating system (OS) of mobiles or embedded devices is based on the Linux kernel. These OSs request random numbers from the Linux kernel for system operation, such as encryption keys and security features. To provide random numbers reliably, the Linux kernel has a dedicated random number generator (Linux Pseudo Random Number Generator, LPRNG). Recently, LPRNG has undergone a major structural changes. However, despite the major changes, no security analysis has been published on the structure of the new LPRNG. Therefore, we analyze these structural changes as a preliminary study to utilize the security analysis of the new LPRNG. Furthermore, the differences between before and after the changes are divided into cryptographic and performance perspectives to identify elements that require security analysis. This result will help us understand the new LPRNG and serve as a base for security analysis.

• The Korean Journal of Applied Statistics
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• v.16 no.2
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• pp.427-440
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• 2003

Many mobile applications, such as games, security software and mathematical applications, use a random number generator(RNG). Since mobile devices operate under a limited battery capacity, the low energy consumption is one of key system requirements. For mobile applications based on an RNG, it is important to use low-power RNGs. In this article, we evaluate the energy efficiency of several well-known RNG algorithms and suggest guidelines for selecting RNGs suitable for mobile application.

• Journal of the Korean Data and Information Science Society
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• v.26 no.3
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• pp.593-610
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• 2015

Adaptive Rejection Sampling (ARS) method is a well-known random number generator to acquire a random sample from a probability distribution, and has the advantage of improving the proposal distribution during the sampling procedures, which update it closer to the target distribution. However, the use of ARS is limited since it can be used only for the target distribution in the form of the log-concave function, and thus various methods have been proposed to overcome such a limitation of ARS. In this paper, we attempt to compare five random number generators based on ARS in terms of adequacy and efficiency. Based on empirical analysis using simulations, we discuss their results and make a comparison of five ARS-based methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.676-682
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• 2018

As the IoT world including WSNs develops, the number of sensor systems that sense information according to the environment based on the principle of IoT is increasing. In order to perform security for each sensor system in such a complicated environment, the security modules must be varied. These problems make hardware/software implementation difficult when considering the system efficiency and hacking/cracking. Therefore, to solve this problem, this paper proposes a pseudorandom number generator (FLT: Pseudo-random Number Generator with Fixed Length Tap unrelated to the variable sensing nodes) with a fixed-length tap that generates a pseudorandom number with a constant period, irrespective of the number of sensing nodes, and has the purpose of detecting anomalies. The proposed FLT-LFSR architecture allows the security level and overall data formatting to be kept constant for hardware/software implementations in an IoT environment. Therefore, the proposed FLT-LFSR architecture emphasizes the scalability of the network, regardless of the ease of implementation of the sensor system and the number of sensing nodes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.2
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• pp.307-315
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• 2017

Random number generator(RNG) is essential in cryptographic applications. As recently a system using small devices such as IoT, Sensor Network, SmartHome appears, the lightweight cryptography suitable for this system is being developed. However due to resource limitations and difficulties in collecting the entropy, RNG designed for the desktop computer are hardly applicable to lightweight environment. In this paper, we propose a lightweight RNG to produce cryptographically strong random number using sensors. Our design uses a Hankel matrix, block cipher as the structure and sensors values as noise source. Futhermore, we implement the lightweight RNG in Arduino that is one of the most popular lightweight devices and estimate the entropy values of sensors and random number to demonstrate the effectiveness and the security of our design.