Browsing by Author "Lee, Hui-Lung"

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A perfect maze based steganographic method
(2010-12-01)
Lee, Hui-Lung
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Lee, Chia-Feng
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Chen, Ling-Hwei
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資訊工程學系
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Department of Computer Science
In steganography, several different types of media have been used as carriers, such as images, audios and video streams, to hide secret data. Nevertheless, various novel media and applications have been developed due to the rapid growth of internet. In this paper, we select maze games as carrier media to conceal secret data. The original idea of embedding data in a maze is proposed by Niwayama et al. Their method has two disadvantages. One is the very small embedding capacity; the other is that the stego maze is not perfect. Here, we propose an improved algorithm for increasing the embedding capacity and preserving the "perfect" property. (C) 2010 Elsevier Inc. All rights reserved.
An efficient algorithm for solving nonograms
(2011-08-01)
Yu, Chiung-Hsueh
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Lee, Hui-Lung
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Chen, Ling-Hwei
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資訊工程學系
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Department of Computer Science
Nonogram is one of logical games popular in Japan and Netherlands. Solving nonogram is a NP-complete problem. There are some related papers proposed. Some use genetic algorithm (GA), but the solution may get stuck in local optima. Some use depth first search (DFS) algorithm, the execution speed is very slow. In this paper, we propose a puzzle solving algorithm to treat these problems. Based on the fact that most of nonograms are compact and contiguous, some logical rules are deduced to paint some cells. Then, we use the chronological backtracking algorithm to solve those undetermined cells and logical rules to improve the search efficiently. Experimental results show that our algorithm can solve nonograms successfully, and the processing speed is significantly faster than that of DFS. Moreover, our method can determine that a nonogram has no solution.
An improved method for hiding data in a maze
(2008-01-01)
Lee, Hui-Lung
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Lee, Chia-Feng
;
Chen, Ling-Hwei
;
資訊工程學系
;
Department of Computer Science
It is common to use image, audio, video streams as host media in steganography. In this paper, we will select mazes as host media to avoid the problem "robustness" concerned by classic host media. The original idea of embedding data in a maze is proposed by Niwayama et al. Their method has two disadvantages. One is very small embedding capacity; the other is that the embedded maze is not perfect. Here, we present an improved algorithm to increase the embedding capacity. Meanwhile, we can still preserve the property "perfect", that is, we can keep the imperceptible property required in steganography.
An improved method for hiding data in a maze
(2008-01-01)
Lee, Hui-Lung
;
Lee, Chia-Feng
;
Chen, Ling-Hwei
;
交大名義發表
;
National Chiao Tung University
It is common to use image, audio, video streams as host media in steganography. In this paper, we will select mazes as host media to avoid the problem "robustness" concerned by classic host media. The original idea of embedding data in a maze is proposed by Niwayama et al. Their method has two disadvantages. One is very small embedding capacity; the other is that the embedded maze is not perfect. Here, we present an improved algorithm to increase the embedding capacity. Meanwhile, we can still preserve the property "perfect", that is, we can keep the imperceptible property required in steganography.
Authentication protocols using Hoover-Kausik's software token
(2006-05-01)
Ku, Wei-Chi
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Lee, Hui-Lung
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資訊工程學系
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Department of Computer Science
In 1999, Hoover and Kausik introduced a software token using the cryptographic camouflage technique and claimed that it can resist various on-line and off-line guessing attacks. Later, Kwon presented an authentication protocol based on the cryptographic camouflage technique and DSA, and pointed out that this initial protocol is vulnerable to an impersonation attack once a server's secret key or private key is compromised. Then, Kwon proposed a modified version that can resist such an impersonation attack by cryptographically embedding the recipient's identity in the user's signature to ensure that only the intended recipient will accept this signature. However, we find that Kwon's modified protocol still has some drawbacks. In this paper, we first demonstrate the drawbacks of Kwon's modified protocol and then propose an improved authentication protocol based on the cryptographic camouflage technique and RSA. Finally, we show that our improved protocol can provide prefect forward secrecy and can resist the off-line guessing attack, the impersonation attack, the replay attack, and the Denning-Sacco attack. Furthermore, the resistance of our improved protocol to the modification attack is also enhanced by additionally using credit-card sized CD-ROMs.
SOLVING JAPANESE PUZZLES WITH LOGICAL RULES AND DEPTH FIRST SEARCH ALGORITHM
(2009)
Jing, Min-Quan
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Yu, Chiung-Hsueh
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Lee, Hui-Lung
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Chen, Ling-Hwei
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資訊工程學系
Japanese puzzle is one of logical games popular in Japan and Netherlands. Solving Japanese puzzle is a NP-complete problem. There are some related papers proposed. Some use genetic algorithm (GA), but the solution may be wrong. Some use depth first search (DFS) algorithm, which is an exhaustive search, the execution speed is very slow. In this paper, we propose a puzzle solving algorithm to treat these problems. Based on the fact that most of Japanese puzzle are compact and contiguous, some logical rules are deduced to paint some cells. Then, the DFS algorithm with the "branch and bound" scheme, which is used to do early termination for those impossible paths, is used to solve those undetermined cells. Experimental results show that our algorithm can solve Japanese puzzles successfully, and the processing speed is significantly faster than that of DFS.