Real-time chaotic video encryption based on multithreaded parallel confusion and diffusion

TL;DR

The paper tackles the challenge of real-time chaotic video encryption by introducing a multithreaded, five-round confusion-diffusion strategy. It leverages two chaotic maps (PLCM and 2DLASM) within a main thread plus multiple assistant threads to process subframes in parallel, using a discretized Chirikov map for confusion and a diffusion rule to modify pixel values. Experimental results on three mainstream CPUs show real-time performance for common video sizes at 24 FPS, while extensive statistical tests (uniformity, correlation, randomness) and security analyses (key space, sensitivity, NPCR/UACI, noise and data-loss resistance) demonstrate strong security properties. The approach is adaptable to other confusion/diffusion schemes and supports hardware/software deployment, offering a practical path toward high-security, real-time chaotic video encryption.

Abstract

Due to the strong correlation between adjacent pixels, most image encryption schemes perform multiple rounds of confusion and diffusion to protect the image against attacks. Such operations, however, are time-consuming, cannot meet the real-time requirements of video encryption. Existing works, therefore, realize video encryption by simplifying the encryption process or encrypting specific parts of video frames, which results in lower security compared to image encryption. To solve the problem, this paper proposes a real-time chaotic video encryption strategy based on multithreaded parallel confusion and diffusion. It takes a video as the input, splits the frame into subframes, creates a set of threads to simultaneously perform five rounds of confusion and diffusion operations on corresponding subframes, and efficiently outputs the encrypted frames. The encryption speed evaluation shows that our method significantly improves the confusion and diffusion speed, realizes real-time 480x480, 576x576, and 768x768 24FPS video encryption using Intel Core i5-1135G7, Intel Core i7-8700, and Intel Xeon Gold 6226R, respectively. The statistical and security analysis prove that the deployed cryptosystems have outstanding statistical properties, can resist attacks, channel noise, and data loss. Compared with existing works, to the best of our knowledge, the proposed strategy achieves the fastest encryption speed, and realizes the first real-time chaotic video encryption that reaches the security level of image encryption. In addition, it is suitable for many confusion, diffusion algorithms and can be easily deployed with both hardware and software.

Figures (13)

• Figure 1: Workflow diagram of the proposed chaotic real-time video encryption strategy ($p_m$: parameters generated by $\mathrm{PRBG}_m$; $s_c$: confusion seed; $f$: subframe).
• Figure 2: Encryption process of main thread $T_m$.
• Figure 3: Encryption process of assistant thread $T_a^i$.
• Figure 4: Speed evaluation of byte generation, confusion, and diffusion steps, (a-c) throughput of all $\mathrm{PRBG_a}$s versus the number of assistant threads, (d-f) average time of confusion operations versus the number of assistant threads, (g-i) average time of diffusion operations versus the number of assistant threads.
• Figure 5: Histograms of plain and cipher images. (a) plain image Lena, (b) - (d) histograms of the red, green, and blue channels of the plain image, (e) cipher image encrypted with PLCM, (f) - (h) histograms of the red, green, and blue channels of the cipher image encrypted with PLCM, (i) cipher image encrypted with 2DLASM, (h) - (j) histograms of the red, green, and blue channels of the cipher image encrypted with 2DLASM.