New Efficient Image Encryption Scheme Based on Partial Encryption Karl Martin Multimedia Lab Dept. of Electrical and Computer Eng. University of Toronto

2 I. Introduction Communications becoming more multimedia in nature – images and video Confidentiality must be provided for next generation applications – e.g., online collaboration Strong encryption, e.g. AES, is not suitable to be applied to entire image/video bitstream – too computationally complex

3 I. Introduction cont’d Partial encryption Encrypt only part of a compressed bit-stream to reduce computational complexity Compression aids encryption by removing redundancy Encrypt “most important” information Make location of unencrypted portion difficult to find

4 III. Proposed Secure Coder

5 III. Proposed Secure Coder cont’d Employs Color Set Partitioning in Hierarchical Trees (C-SPIHT), wavelet-based coding Coder directs stream cipher to encrypt certain bits after color image coding Coding efficiency is unaffected since coded bits are simply replaced (encrypted) Most important bits are encrypted while progressive/embedded coding makes unencrypted bits difficult to determine

6 IV. Simulation Results Images decoded without decrypting LenaMapDocumentTulip