X264 — Jigsaw

./x264 --input-res 1920x1080 --fps 30 --jigsaw --jigsaw-key deadbeef12345678 \ -o encrypted.264 input.yuv Decryption (requires modified ffmpeg with jigsaw support):

Abstract With the proliferation of cloud-based video storage and real-time streaming, ensuring confidentiality without compromising compression efficiency is a significant challenge. Traditional full encryption of video bitstreams destroys the compression structure, making streams unplayable without decryption. This paper introduces Jigsaw x264 , a selective encryption scheme integrated into the x264 encoder. By treating each frame as a puzzle, the algorithm applies a pseudo-random permutation of macroblock slices, akin to reassembling jigsaw pieces, while leaving critical headers intact for decoder compatibility. Experimental results show that Jigsaw x264 achieves 98% perceptual degradation with only 8% overhead in encoding time and negligible bitrate increase. 1. Introduction The x264 encoder is the most widely used software library for H.264/AVC compression. However, standard x264 does not provide native encryption. Naïve approaches — such as encrypting the entire bitstream — render the stream unparseable by decoders and break features like random access and error resilience. jigsaw x264

Raw YUV → x264 core (prediction, DCT, quant) → Entropy encoder → → Jigsaw Permutation (slice-level) → NAL packetizer → Output stream Each slice (a set of macroblocks) is treated as a jigsaw piece. For a frame with ( N ) slices, we generate a permutation ( P ) from a 128-bit key via Fisher-Yates shuffle. By treating each frame as a puzzle, the

ffmpeg -jigsaw-key deadbeef12345678 -i encrypted.264 output.mp4 Introduction The x264 encoder is the most widely