Digital steganography provides a way to communicate over unsecure channels by hiding data in digital media and exchanging it with the recipient, who in turn extracts it. Covert communication is used in many fields, as well as in the private sphere.

In this thesis our goal was to provide a state-of-the-art review on steganography techniques in publicly available tools, identify the most common steganography techniques in publicly accessible tools and evaluate these based on the properties of imperceptibility and capacity.

The techniques we found to be the most common were LSB, EOF-injection, DCT and an adaptive algorithm. We evaluated the most common tools that used these techniques, which were F5, Jsteg, OpenPuff, Steghide, SilentEye, and StegoStick. The spatial domain tools (SilentEye and StegoStick) outperformed the other tools when embedding in images, having a high capacity while retaining a relatively high imperceptibility. When embedding in audio,the transform and adaptive domain tools (F5, Jsteg, and OpenPuff) had a higher capacity while also upholding a high imperceptibility