Visual Cryptography
Image Secret Sharing
Private-Key Cryptosystem
ISS Selective Encryption
Secure Image Coding


Image Secret Sharing

Unlike visual secret sharing schemes which require the halftoning process to encrypt gray-scale or color visual data, image secret sharing solutions operate directly on the bit planes of the digital input. The input image is decomposed into bit-levels which can be viewed as binary images. Using the {k,n} threshold concept, the image secret sharing procedure encrypts individual bit-planes into the binary shares which are used to compose the share images with the representation identical to that of the input image. Depending on the number of the bits used to represent the secret (input) image, the shares can contain binary, gray-scale or color random information. Thus, the degree of protection afforded by image secret sharing methods increases with the number of bits used to represent the secret image.



  Secret gray-scale image   Share 1   Share 2   Decrypted image  

The decryption operations are performed on decomposed bit-planes of the share images. Using the contrast properties of the conventional {k,n}-schemes, the decryption procedure uses shares' bits to recover the original bit representation and compose the secret image. The decrypted output is readily available in a digital format, and is identical to the input image. Because of the symmetry constraint imposed on the encryption and decryption process, image secret sharing solutions hold the perfect reconstruction property. This feature in conjunction with the overall simplicity of the approach make this approach attractive for real-time secret sharing based encryption/decryption of natural images.



color image
  Share 1   Share 2   Decrypted image  


bullet 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
bulletR. 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
bulletR. 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.
bulletR. 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.
bulletR. Lukac and K.N. Plataniotis, "Bit-Level Based Secret Sharing for Image Encryption," Pattern Recognition, vol. 38, no. 5, pp. 767-772, May 2005.
bulletR. Lukac and K.N. Plataniotis, "Image Representation Based Secret Sharing," Communications of the CCISA (Chinese Cryptology & Information Security Association), Special Issue on Image Secret Sharing and Quantum Cryptography, vol. 11, no. 2, pp. 103-114, April 2005.
bulletR. Lukac and K.N. Plataniotis, "Colour Image Secret Sharing," IEE Electronics Letters, vol. 40, no. 9, pp. 529-530, April 2004.

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Last update: 10/15/06

2006 Rastislav Lukac