Md5deep and hashdeep
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. hashdeep is a program to compute, match, and audit hashsets.
- Ask Ubuntu. Check the Correctness of Copied Files. 
- TaoSecurity. 2005-08-08. Using md5deep. 
- Ventura, Luis. 2010-05-31. Using hashdeep to Ensure Data Integrity.