IMAGE ENCRYPTION APPARATUS AND IMAGE DECRYPTION APPARATUS, IMAGE ENCRYPTION METHOD AND IMAGE DECRYPTION METHOD, AND IMAGE ENCRYPTION PROGRAM AND IMAGE DECRYPTION PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide an image encryption apparatus which strikes a balance between arithmetic load reduction and confidentiality, gives an index for a designer to perform tuning for trade-off between load and safety, and is also capable of dealing with a change in characteristics of image data.;SOLUTION: On the basis of size information indicating a size of slice data and block number information indicating the number of macro blocks constituting the slice data, a size calculation section 201 calculates an encryption data size 204 which is a data size unit of a portion to be encrypted in the slice data, and a non-encryption data size 205 which is a data size unit of a portion not to be encrypted in the slice data. An encryption processing section 202 divides the slice data into first data of the encryption data size 204 and second data of the non-encryption data size 205 alternately from the head, and encrypts and outputs each of first data items.;COPYRIGHT: (C)2012,JPO&INPIT