| 摘要 |
A data security system for digitized data that can use both encryption and steganographic techniques. Data is encrypted using selected encryption protocols and algorithms. The resulting ciphertext is then treated to a steganographic encoding into a secondary data stream. This encoding is performed by replacing the least significant bit of selected bytes in the secondary data stream with the bits of the ciphertext. Selection of those bytes is performed via ciphertext created using a separate encryption procedure that uses an encryption key as both the key and as the data to be encrypted. The format of the secondary data stream is usually chosen so that it will not be obvious that it has been modified. The modified data can either be stored for later use or transmitted to the intended recipient. Decoding is accomplished by using the cyphertext to find the selected bytes in the modified secondary data stream, extracting the least significant bits, and reassembling those bits into the original data. These encryption techniques are also used for backing up data in a secure manner. The data to be backed up is first encrypted using selected encryption protocols and algorithms. The resulting ciphertext is then split into multiple parts and each part is stored on a separate floppy disk in selected locations that are determined by a separate encryption process which produces a selection cyphertext to select the storage locations. The remaining areas of each floppy disk are then filled in with random data to obscure the identity of the backed up information. Restoration of the original data is accomplished by using the selection cyphertext to locate the stored data on each floppy, reading that data and reassembling it into a data block, and then merging the data blocks from each floppy to recreate the original data. |
