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Private-Key Cryptosystem

secret image shares solution

Definition: A private-key cryptosystem can be obtained using the visual cryptography concepts or perfect-reconstruction based image secret sharing.

A (2,2)-scheme is the most popular solution within the (k,n) framework due to its common acceptance as a private-key cryptosystem Such a cryptographic solution encrypts the secret image into two noise-like shares. One of the two generated shares can be viewed as a private share or private-key, and is kept by the owner. The other share represents a public share which can be transmitted over an untrusted communication channel. The secret image is reconstructed only if both the public and private shares are used for decryption.

A private-key cryptosystem can be obtained using the visual cryptography concepts or perfect-reconstruction based image secret sharing . Both these solutions encrypt each pixel of the secret image into a block of share pixels and because of their expansion nature, such solutions produce the shares with the enlarged spatial resolution. To reduce the complexity, a cost-effective private-key cryptosystem in uses pixel operations to both encrypt and decrypt the images. As a result, the solution produces the shares with spatial dimensions identical to those of the secret image (Figure 1). In addition, operating on the bit-levels of the processed images, the solution satisfies the essential perfect reconstruction property. Thus, similarly to the ( k,n ) image secret sharing framework proposed in , the private-key cryptosystem in recovers the original secret image (Figure 1).

The utilization of the bit-level processing operations in allows for selective encryption of image bit-planes. Such an approach offers solutions which differ in their security characteristics. For example, as it is shown in Figure 2, sufficient protection is usually obtained when the two or three most significant bits of the secret image’s pixels are encrypted.

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over 6 years ago

hello sir,

i need 15 pages for private key cryptosystwm in network security...in assignment work.