snowdrop is intended to bring (relatively) invisible and modification-proof watermarking to a new realm of “source material” – written word and computer source codes.
The information is not being embedded in the least significant portions of some binary output, as it would be with a traditional low-level steganography, but into the source itself. The idea, at least for English, isn’t new – there was some serious work done by Mikhail Atallah from Purdue University. Snowdrop is merely an attempt to provide a reliable, useful tool to implement those source-level watermarking / steganography capabilities.
Because of some tricks, such as using specially crafted MD5 shortcuts, it gives certain additional advantages to its potential users, such as integrity and privacy of embedded information, or an
ability to demonstrate the origin of a document to the public. Separate logical channels are used to carry highly redundant watermark to ensure it is extremely difficult to remove this information by accident, simple reformatting, etc.
It is useful in forensic investigations and security actions. It provides three commands: sd-eng, sd-engf and sd-c. sd-eng and sd-engf provide watermarking for draft-quality and fine-quality English language text documents, respectively, whereas sd-c provides experimental C source code watermarking.
This is free and open source software.
Website: salsa.debian.org/pkg-security-team/snowdrop
Support:
Developer: Michal Zalewski
License: GNU General Public License v2.0
snowdrop is written in C. Learn C with our recommended free books and free tutorials.
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