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Private-Key Cryptosystem
Among numerous possible {k,n} threshold
configurations, the simplest case is constituted by {2,2} schemes. By
reducing the number of shares to only two pieces, a private-key
cryptosystem is obtained, as each of the two generated shares can be
used as the decryption key for the other share.
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Secret gray-scale image |
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Share 1 |
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Decrypted image |
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Unlike the traditional secret sharing solutions which
encrypt each secret pixel into a block of share pixels, a
cost-effective variant of the image secret sharing framework with
the perfect reconstruction property reduces the encryption and
decryption operations from the block level to the pixel level. The
solution operates on the decomposed bit-levels of the secret image.
Each decomposed bit of the original pixels is encrypted into a
single output bit for each of the two shares. In this way, the
produced shares have the same spatial resolution as that of the
original image, thus allowing significant computational and memory
savings and efficient transmission of the shares in public networks.
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Secret color image |
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Share 1 |
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Decrypted image |
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References: |
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R. Lukac and K.N. Plataniotis, Secure Color Imaging. In Color
Image Processing: Methods and Applications, (eds.) R. Lukac and
K.N. Plataniotis, CRC Press / Taylor & Francis, pp. 185-202, October 2006. ISBN 0-8493-9774-X |
| R. Lukac, K.N. Plataniotis, and C.N. Yang,
Image Secret Sharing. In Encyclopedia of Multimedia, (ed.)
B. Furth, Springer-Verlag, pp. 328-335, January 2006. Including
short articles: Compression in Image Secret Sharing (pp. 86-87),
Halftoning-Based Visual Secret Sharing (pp. 363-364), Image
Watermarking Using Visual Cryptography (pp. 337-338), Private-Key
Cryptosystem (pp. 712-714), Threshold Schemes with Minimum Pixel
Expansion (pp. 849-850), Visual Cryptography (pp. 950-951). ISBN
0-387-24395-X |
| R. Lukac and K.N. Plataniotis, "A Cost-Effective Encryption Scheme for Color Images,"
Real-Time Imaging, Special Issue on Multi-Dimensional Image
Processing, vol. 11, no. 5-6, pp. 454-464, October-December 2005. |
| R. Lukac and K.N. Plataniotis, "Digital Image Indexing Using Secret Sharing Schemes: A Unified Framework for Single-Sensor Consumer Electronics," IEEE Transactions on Consumer Electronics, vol. 51, no. 3, pp. 908-916, August 2005. |
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