  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.
