recursively compute hashsums or piecewise hashings

 hashdeep is a set of tools to compute MD5, SHA1, SHA256, tiger
 and whirlpool hashsums of arbitrary number of files recursively.
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 The main hashdeep features are:
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   * It can compare those hashsums with a list of known hashes;
   * The tools can display those that match the list or those that
     does not match;
   * It can display a time estimation when processing large files.
   * It can do piecewise hashing (hash input files in arbitrary
     sized blocks).
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 This package is useful in forensics investigations.