661 research outputs found
A Novel Latin Square Image Cipher
In this paper, we introduce a symmetric-key Latin square image cipher (LSIC)
for grayscale and color images. Our contributions to the image encryption
community include 1) we develop new Latin square image encryption primitives
including Latin Square Whitening, Latin Square S-box and Latin Square P-box ;
2) we provide a new way of integrating probabilistic encryption in image
encryption by embedding random noise in the least significant image bit-plane;
and 3) we construct LSIC with these Latin square image encryption primitives
all on one keyed Latin square in a new loom-like substitution-permutation
network. Consequently, the proposed LSIC achieve many desired properties of a
secure cipher including a large key space, high key sensitivities, uniformly
distributed ciphertext, excellent confusion and diffusion properties,
semantically secure, and robustness against channel noise. Theoretical analysis
show that the LSIC has good resistance to many attack models including
brute-force attacks, ciphertext-only attacks, known-plaintext attacks and
chosen-plaintext attacks. Experimental analysis under extensive simulation
results using the complete USC-SIPI Miscellaneous image dataset demonstrate
that LSIC outperforms or reach state of the art suggested by many peer
algorithms. All these analysis and results demonstrate that the LSIC is very
suitable for digital image encryption. Finally, we open source the LSIC MATLAB
code under webpage https://sites.google.com/site/tuftsyuewu/source-code.Comment: 26 pages, 17 figures, and 7 table
A Novel Chaotic Image Encryption using Generalized Threshold Function
In this paper, after reviewing the main points of image encryption and
threshold function, we introduce the methods of chaotic image encryption based
on pseudorandom bit padding that the bits be generated by the novel generalized
threshold function (segmentation and self-similarity) methods. These methods
decrease periodic effect of the ergodic dynamical systems in randomness of the
chaotic image encryption. The essential idea of this paper is that given
threshold functions of the ergodic dynamical systems. To evaluate the security
of the cipher image of this scheme, the key space analysis, the correlation of
two adjacent pixels and differential attack were performed. This scheme tries
to improve the problem of failure of encryption such as small key space and
level of security.Comment: 7 pages, 5 figures, Published in international Journal of Computer
Applications (March 2012
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
Cryptanalysis of two chaotic encryption schemes based on circular bit shift and XOR operations
Recently two encryption schemes were proposed by combining circular bit shift
and XOR operations, under the control of a pseudorandom bit sequence (PRBS)
generated from a chaotic system. This paper studies the security of these two
encryption schemes and reports the following findings: 1) there exist some
security defects in both schemes; 2) the underlying chaotic PRBS can be
reconstructed as an equivalent key by using only two chosen plaintexts; 3) most
elements in the underlying chaotic PRBS can be obtained by a differential
known-plaintext attack using only two known plaintexts. Experimental results
are given to demonstrate the feasibility of the proposed attack.Comment: 17 pages, 8 figure
Breaking a Chaotic Cryptographic Scheme Based on Composition Maps
Recently, a chaotic cryptographic scheme based on composition maps was
proposed. This paper studies the security of the scheme and reports the
following findings: 1) the scheme can be broken by a differential attack with
chosen-plaintext, where is the size of
plaintext and is the number of different elements in plain-text; 2) the
scheme is not sensitive to the changes of plaintext; 3) the two composition
maps do not work well as a secure and efficient random number source.Comment: 9 pages, 7 figure
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