dc3dd is a patched version of GNU dd to include a number of features useful for computer forensics. Many of these features were inspired by dcfldd, but were rewritten for dc3dd.

Pattern writes. The program can write a single hexadecimal value or a text string to the output device for wiping purposes.
Piecewise and overall hashing with multiple algorithms and variable size windows. Supports MD5, SHA-1, SHA-256, and SHA-512. Hashes can be computed before or after conversions are made.
Progress meter with automatic input/output file size probing
Combined log for hashes and errors
Error grouping. Produces one error message for identical sequential errors
Verify mode. Able to repeat any transformations done to the input file and compare it to an output.
Ability to split the output into chunks with numerical or alphabetic extensions