| 摘要 |
<P>PROBLEM TO BE SOLVED: To encrypt/decrypt image data at high speed without adding special hardware or imposing a big burden to/on a CPU. <P>SOLUTION: The data encrypting device compresses an image data 10 by a compression method which cannot conduct expansion processing if any part of compression data 11 is not proper, extracts a part of the compression data 11 as an encryption key data 12, and conducts zero clear for the part, where the encryption key data 12 is extracted from among the compression data 11 to convert into an encryption data 13. The encryption data 13 cannot be restored, because its leading part is destroyed. Moreover, since it makes restoration impossible using the nature of the compression data, encryption/decryption can be done by a simple processing. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
