This document discusses JPEG steganography techniques. It covers the steps involved in JPEG compression including preprocessing, transformation using discrete cosine transform, quantization, and encoding. It then discusses how information can be hidden in JPEG images using least significant bit steganography by modifying the least significant bit of each pixel. Popular steganography tools for JPEG images are also listed. Methods for detecting hidden information through steganalysis of JPEG images are outlined, including using chi-square attacks and other statistical analyses.