Secure Real-Time Chaotic Partial Encryption of Entropy-Coded Multimedia Information for Mobile Devices: Smartphones

Abstract

Smartphones penetration-rate continues expanding, from 44% in 2017 up to 59% expected increase in 2022 as reported by Strategy Analytics. At present, smartphones dominate the global mobile traffic, which in turn is dominated by video communications. For mobile systems with limited power capabilities, the processing of real-time multimedia information with affixed security represents a real challenge. In this work, we propose a high-performance encryption scheme capable of running on low-power smartphones without holding back video coding operation. We are aimed at destroying the meaning of the entropy coded bitstream by inserting random bit errors to induce error propagation and impede natural self-resynchronization process. The scheme consists of three main process: 1) A new integer chaos-based Coupled-Map Lattice-CML for creating secure pseudo-random trajectories; 2) Random bit flipping of the bitstream based on a Dynamic Reference Point (DRP) not exposed to attackers; and 3) Random selection of CML byte-trajectories for both DRP and bit flipping processes for increased security. Implementation of the scheme on smartphones with different CPU-power capabilities shows excellent performance to handle high-bandwidth real-time video smoothly (one-to-one and group calls). The scheme provides high scalable security with encrypted data volume fluctuating between 0.7%-3% of the total compressed data (video and still images).

Keywords

• Chaotic systems
• coupled-map lattice
• entropy coding
• partial encryption