• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.103-105
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• 2009

This paper presents a pseudorandom tag arrangement for improved RFID based mobile robot localization. First, four repetitive tag arrangements, including square, parallelogram, tilted square, and equilateral triangle, are examined. For each tag arrangement, the difficulty in tag installation and the problem of tag invisibility are discussed. Then, taking into account both tag invisibility and tag installation, a pseudorandom tag arrangement is proposed, which is inspired from a Sudoku puzzle. It is shown that the proposed tag arrangement exhibits spatial randomness quite successively without increased difficulty in installation.

• ETRI Journal
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• v.32 no.2
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• pp.222-229
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• 2010

A conventional pseudorandom sequence generator creates only 1 bit of data per clock cycle. Therefore, it may cause a delay in data communications. In this paper, we propose an efficient implementation method for a pseudorandom sequence generator with parallel outputs. By virtue of the simple matrix multiplications, we derive a well-organized recursive formula and realize a pseudorandom sequence generator with multiple outputs. Experimental results show that, although the total area of the proposed scheme is 3% to 13% larger than that of the existing scheme, our parallel architecture improves the throughput by 2, 4, and 6 times compared with the existing scheme based on a single output. In addition, we apply our approach to a $2{\times}2$ multiple input/multiple output (MIMO) detector targeting the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) system. Therefore, the throughput of the MIMO detector is significantly enhanced by parallel processing of data communications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6161-6176
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• 2018

Pseudorandom numbers are useful in cryptographic operations for using as nonce, initial vector, secret key, etc. Security of the cryptosystem relies on the secret key parameters, so a good pseudorandom number is needed. In this paper, we have proposed a new approach for generation of pseudorandom number. This method uses the three dimensional combinational puzzle Rubik Cube for generation of random numbers. The number of possible combinations of the cube approximates to 43 quintillion. The large possible combination of the cube increases the complexity of brute force attack on the generator. The generator uses cryptographic hash function. Chaotic map is being employed for increasing random behavior. The pseudorandom sequence generated can be used for cryptographic applications. The generated sequences are tested for randomness using NIST Statistical Test Suite and other testing methods. The result of the tests and analysis proves that the generated sequences are random.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.3-16
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• 2010

Key derivation functions are used within many cryptographic systems in order to generate various keys from a fixed short key string. In this paper we survey a state-of-the-art in the key derivation functions and wish to examine the soundness of the functions on the view point of provable security. Especially we focus on the key derivation functions using pseudorandom functions which are recommended by NISI recently, and show that the variant of Double-Pipeline Iteration mode using pseudorandom permutations is a pseudorandom function. Block ciphers can be regarded as practical primitives of pseudorandom permutations.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.12 no.2
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• pp.109-118
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• 2008

We present a new version of the first return time test for pseudorandomness. Let $R_n$ be the first return time of initial n-block with overlapping. An algorithm to calculate the probability distribution of the first return time $R_n$ for each starting block is presented and used to test pseudorandom number generators. The standard Z-test for log $R_n$ is applied to test the pseudorandom number generators.

• Bulletin of the Korean Mathematical Society
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• v.35 no.1
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• pp.173-187
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• 1998

Several aspects of pseudorandom number generators are investigated from the viewpoint of ergodic theory. An algorithm of generating pseudorandom numbers proposed and shown to behave reasonably well.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.3
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• pp.13-22
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• 2001

The notion of pseudorandomness plays an important role in modem cryptography as well as computer science. We show a simple and practical construction of a pseudorandom generator based on the intractability of the problem in braid groups. The generator is proved as secure as a hard instance of a variant of the conjugacy problem.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.2
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• pp.27-32
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• 2004

Absolute optical angle sensor is described that is an essentially digital opto-electronic device. Its purpose is to resolve the relative and absolute angle position of coded disk using Pseudorandom-code and Geometry-code. In this technique, the angular position of disk is determined in coarse sense first by Pseudorandom-code. A further fine angular position data based on Pixel count is obtained by Geometry-code which result 0.006$^{\circ}$ resolution of the system provided that 7 ${\mu}{\textrm}{m}$ line image sensor are used. The proposed technique is novel in a number of aspects, such that it has the non-contact reflective nature, high resolution of the system, relatively simple code pattern, and inherent digital nature of the sensor. And what is more the system can be easily modified to torque sensor by applying two coded disks in a manner that observe the difference in absolute angular displacement. The digital opto-electronic nature of the proposed sensor, along with its reporting of both torque and angle, makes the system ideal for use in intelligent vehicle systems. In this communication, we propose a technique that utilizes Pseudorandom-code and Geometry-code to determine accurate angular position of coded disk. We present the experimental results to demonstrate the validity of the idea.

• ETRI Journal
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• v.25 no.2
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• pp.89-100
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• 2003

The notion of pseudorandomness is the theoretical foundation on which to consider the soundness of a basic structure used in some block ciphers. We examine the pseudorandomness of the block cipher KASUMI, which will be used in the next-generation cellular phones. First, we prove that the four-round unbalanced MISTY-type transformation is pseudorandom in order to illustrate the pseudorandomness of the inside round function FI of KASUMI under an adaptive distinguisher model. Second, we show that the three-round KASUMI-like structure is not pseudorandom but the four-round KASUMI-like structure is pseudorandom under a non-adaptive distinguisher model.

• Journal of applied mathematics & informatics
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• v.24 no.1_2
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• pp.461-470
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• 2007

In CRYPTO 1995, Bellare, $Gu\'{e}rin$, and Rogaway proposed a very efficient message authentication scheme. This scheme is secure against adaptive chosen message attacks, under the assumption that its underlying primitive is a pseudorandom function. This article studies how to weaken that assumption. For an adaptive chosen message attack, we take into account two scenarios. On the one hand, the adversary intercepts the authenticated messages corresponding to messages chosen adaptively by herself, so the verifier does not receive them. On the other hand, the adversary can only eavesdrop the authenticated messages corresponding to messages chosen adaptively by herself, so the verifier receives them. We modify the original scheme. In the first scenario, our scheme is secure if the underlying primitive is a pseudorandom function. In the second scenario, our scheme is still secure under a weaker assumption that the underlying primitive is an indistinguishable-uniform function.