5,599 research outputs found
Roadmap on optical security
Postprint (author's final draft
Deciphering a novel image cipher based on mixed transformed Logistic maps
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 ; 2) two pairs of chosen plain-images
and the corresponding cipher-images with computational complexity of ,
where is the number of pixels in the plain-image. In contrast, the required
condition in the previous deciphering method is eighty-seven pairs of chosen
plain-images and the corresponding cipher-images with computational complexity
of . In addition, three other security flaws existing in most
Logistic-map-based ciphers are also reported.Comment: 10 pages, 2 figure
On the Design of Perceptual MPEG-Video Encryption Algorithms
In this paper, some existing perceptual encryption algorithms of MPEG videos
are reviewed and some problems, especially security defects of two recently
proposed MPEG-video perceptual encryption schemes, are pointed out. Then, a
simpler and more effective design is suggested, which selectively encrypts
fixed-length codewords (FLC) in MPEG-video bitstreams under the control of
three perceptibility factors. The proposed design is actually an encryption
configuration that can work with any stream cipher or block cipher. Compared
with the previously-proposed schemes, the new design provides more useful
features, such as strict size-preservation, on-the-fly encryption and multiple
perceptibility, which make it possible to support more applications with
different requirements. In addition, four different measures are suggested to
provide better security against known/chosen-plaintext attacks.Comment: 10 pages, 5 figures, IEEEtran.cl
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