hashdeep is a program to compute, match, and audit hashsets.
md5deep is a set of programs to compute MD5, SHA-1, SHA-256, Tiger, or Whirlpool message digests on an arbitrary number of files. md5deep is similar to the md5sum program found in the GNU Coreutils package, but has the following additional features:
* Recursive operation - md5deep is able to recursive examine an entire directory tree. That is, compute the MD5 for every file in a directory and for every file in every subdirectory.
* Comparison mode - md5deep can accept a list of known hashes and compare them to a set of input files. The program can display either those input files that match the list of known hashes or those that do not match. Hashes sets can be drawn from Encase, the National Software Reference Library, iLook Investigator, Hashkeeper, md5sum, BSD md5, and other generic hash generating programs. Users are welcome to add functionality to read other formats too!
* Time estimation - md5deep can produce a time estimate when it's processing very large files.
* Piecewise hashing - Hash input files in arbitrary sized blocks
* File type mode - md5deep can process only files of a certain type, such as regular files, block devices, etc.