Problem and Motivation Security and Power Insecure network Symmetric Encryption Technique Video Encoder Secure Video Encoder Attacks Decryption Video Decoder Secure Video Decoder Battery -Operated Devices Problem and Motivation Mobile multimedia applications are vulnerable to security attacks in wireless networks Significant computation for video encryption is expected on battery-operated mobiles Evaluate symmetric video encryption schemes w.r.t. energy Analytical Study Experimental Study 50 % Algorithm NAIVE SELECTIVE Zig-Zag VEA Encryption of all frames Partial encryption (e.g. Intra-blocks) Shuffling coefficients from Quantization XORing and Half Encryption using even byte distribution Moderate Very Low High 100 % 59 % < 1 % Security Relative Energy 10 20 30 40 50 60 70 80 90 FOREMAN.qcif NEWS.qcif Video Clips Measured Energy (Joules) Negligible Energy Overhead Encoding without Encryption Encoding with Encryption (Selective) Encoding with Encryption (Naïve)

Reliability and Power Critical real-time applications on battery-operated embedded systems Demand high reliability and low power consumption (eg: Remote Sensing) Strong relationship between reliability and power consumption with technology advance Reliability approaches require extra energy consumption (eg: Triple Modular Redundancy) Power management techniques affect the system reliability (eg: Voltage scaling and soft error rate) Advance technology causes higher fault rate (eg: lower voltage, higher density) Composibility contributes system level perspectives with knobs for coordinating and optimizing reliability, energy consumption and time constraints Increase Power Reliability Manager: Redundancy Power Manager: DVS, DPM Decrease Reliability COMPOSIBILITY Coordinator  Optimal Solution (1) Compute optimal speed for min energy usage within deadline (2) Control knobs unless feasible for reliability (3) Apply redundancy to satisfy reliability P substrate N+ gate drain source α particle +- -+