Topic
Cipher
About: Cipher is a research topic. Over the lifetime, 9409 publications have been published within this topic receiving 110309 citations. The topic is also known as: cypher & cryptographic algorithm.
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TL;DR: This paper analyzes the security weakness of a novel image cipher based on mixed transformed logistic maps and reveals six odd integer keys and three chaotic keystreams equivalent to three chaotic keys through two different methods.
Abstract: Recently, a novel image cipher [Multimed Tools Appl (2012) 56:315---330] was proposed based on mixed transformed logistic maps. The cipher includes three parts: initial permutation of all the pixels with six odd keys, nonlinear diffusion using the first chaotic keystream and xoring the second chaotic keystream with the resultant values, and Zig-Zag diffusion with the third chaotic keystream. It was claimed that the nonlinear diffusion using the first chaotic map, xoring with the second chaotic map and the Zig-Zag diffusion with the third chaotic map are done to improve the security against the known/chosen plaintext attack. However, the cipher is insecure against chosen plaintext attack. In this paper, we analyze the security weakness of the cipher. As for different images, three chaotic keys keep unchanged so that three chaotic keystreams are also fixed. Our target is to reveal six odd integer keys and three chaotic keystreams equivalent to three chaotic keys. By applying chosen plaintext attack, we can reveal them through two different methods. Experimental results also verify our assertion.
28 citations
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TL;DR: In this paper, a rapid key encryption procedure employing symmetric key adopting matrix array was practiced and a complex and multilayered key generation scheme employing pseudorandom sequence, DCT, quantization and scrambling was adapted.
Abstract: The significance of cipher communication against hackers has been strongly felt by the cyber lawmakers. In this direction a yet another double-edged knife cipher methodology employing image encryption (first edge) and multilayered cryptic key (second edge) has been proposed. In this paper, a rapid key encryption procedure employing symmetric key adopting matrix array was practiced. A complex and multilayered key generation scheme employing pseudorandom sequence, DCT, quantization and scrambling was adapted. The operations like diffusion and substitutions were inherently inducted in the proposed scheme to provide faster convergence of cipher image. The effectiveness of the proposed scheme was verified by performing security analysis and also metrics evaluation. Further the present results were compared with the available results and the merits of the same have been highlighted.
28 citations
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TL;DR: This paper re-evaluates the security of an image cipher based on transformed logistic maps and proves that the image cipher can be deciphered efficiently under two different conditions: two pairs of known plain-images and the corresponding cipher-images with computational complexity of O(218 + L).
Abstract: Since John von Neumann suggested utilizing Logistic map as a random number generator in 1947, a great number of encryption schemes based on Logistic map and/or its variants have been proposed. This paper re-evaluates the security of an image cipher based on transformed logistic maps and proves that the image cipher can be deciphered efficiently under two different conditions: (1) two pairs of known plain-images and the corresponding cipher-images with computational complexity of O(218 + L); (2) two pairs of chosen plain-images and the corresponding cipher-images with computational complexity of O(L), where L is the number of pixels in the plain-image. In contrast, the required condition in the previous deciphering method is 87 pairs of chosen plain-images and the corresponding cipher-images with computational complexity of O(27 + L). In addition, three other security flaws existing in most Logistic-map-based ciphers are also reported.
28 citations
01 Jan 1998
TL;DR: The proposed candidate - called DFC as for "Decorrelated Fast Cipher" - is based on the recent decorrelation technique and provides provable security against several classes of attacks which include Differential Cryptanalysis and Linear Cryptanalysis.
Abstract: This report presents a response to the call for candidates issued by the National Institute for Standards and Technologies (the Advanced Encryption Standard project). The proposed candidate - called DFC as for "Decorrelated Fast Cipher" - is based on the recent decorrelation technique. This provides provable security against several classes of attacks which include Differential Cryptanalysis and Linear Cryptanalysis.
28 citations
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08 Oct 2008
TL;DR: In this paper, a digital signature checking center first checks the identity of the signature checking subscriber, and subsequently executes the checking to the signature file, which is all completed with a combined symmetrical key technique.
Abstract: A digital signature method based on CSK establishes a digital signature checking center on the website for checking the signature file. A client computer is established with a ciphering system and a digital signature protocol. Each subscriber is distributed with a hardware device of the cipher key. A signature subscriber uses the cipher key for executing digital signature to the file. The digital signature protocol adopts a combined symmetrical cipher technique for executing digital signature to the file and realizes that the signature cipher is different each time. A signature checking subscriber also uses a cipher key for checking the signature file. The digital signature checking center firstly checks the identity of the signature checking subscriber, and subsequently executes the checking to the signature file. The identity checking protocol and the digital signature checking protocol are all completed with a combined symmetrical key technique thereby realizing the digital signature of the file and the checking to the signature file.
28 citations