Overview on Partial Image Encryption Approaches
Image encryption is vital to ensure confidential transmission and storage of images over internet. However a real-time image encryption is still a challenge due to large amount of data involved. A traditional approach for content access control is to first encode data with a standard compressor and then perform full encryption of the compressed bit-stream with a standard cipher (DES, AES, etc.). In this scheme called fully layered, encryptions are totally disjoint process. The limitation of fully layered scheme consists of altering the original bit-stream syntax. Therefore, many functionalities of the encoding scheme may be disabled (e.g., scalability).