In this paper, we propose a layered multicast encryption scheme that provides flexible access control to motion JPEG2000 code streams. JPEG2000 generates layered code streams and offers flexible scalability in characteristics such as resolution and SNR. The layered multicast encryption proposal allows a sender to multicast the encrypted JPEG2000 code streams such that only designated groups of users can decrypt the layered code streams. While keeping the layering functionality, the proposed method offers useful properties such as 1) video quality control using only one private key, 2) guaranteed security, and 3) low computational complexity comparable to conventional non-layered encryption. Simulation results show the usefulness of the proposed method.

This letter proposes a new shaping algorithm (CRSA: CDV Reduction Shaping Algorithm) that can freely reduce the maximum CDV value of a cell stream to any predetermined value. There is a trade off between shaping delay and the maximum CDV value reduction achieved when using CRSA. The shaper using CRSA (CR-shaper) output satisfies the Peak Cell Rate Reference Algorithm set with the CR-shaper parameters.