套件： snowdrop (0.02b-13)

plain text watermarking and watermark recovery

Snowdrop provides reliable, difficult to remove steganographic watermarking of text documents (internal memos, draft research papers, advisories and other writing) and C sources (limited distribution software, licensed software, or freely available code) so that:

 (1) leaks can be identified if the data goes public.
 (2) original source can be determined and demonstrated if part of the
     document is claimed by somebody else, copied without permission, etc.

Snowdrop uses redundant steganography using four different logical channels, and should be proof to many modifications, including reformatting, spell checking and so on.

This package 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.

Warning: Snowdrop is currently in beta, and may produce bad or corrupted results, especially when run on C source code.