Please note, this is a STATIC archive of website hashcat.net from 08 Oct 2020, cach3.com does not collect or store any user information, there is no "phishing" involved.

Table of Contents

Distributing workload in oclhashcat

Description

This article explains how to split large brute-force projects using oclHashcat.

Why do it this way?

Rather than just leaving a project running for days on end, you can split the project into chunks making it more manageable. Another benefit is you could also give other users / computers parts of the projects to run decreasing the overall run-time.

Example

In this example, I'll setup a project to run mixalpha-num length 8:

Charset: 62

Length: 8

Lets say I get 2 billion/sec on my GPU. To calculate total crack-time, divide total_combinations by GPU speed/sec:

Now, I want to break it up into 4 hr long projects each so, to work out how many parts of the charset are in each project:

Basically, round it down to a whole number and put however many chars from the charset in each project and use the custom charsets to define whats being used:

./oclHashcat.bin -1 ?d?l?u -2 01234567 -o [output-file] [hashes-file] ?1?1?1?1 ?1?1?1?2
./oclHashcat.bin -1 ?d?l?u -2 89abcdef -o [output-file] [hashes-file] ?1?1?1?1 ?1?1?1?2
./oclHashcat.bin -1 ?d?l?u -2 ghijklmn -o [output-file] [hashes-file] ?1?1?1?1 ?1?1?1?2
./oclHashcat.bin -1 ?d?l?u -2 opqrstuv -o [output-file] [hashes-file] ?1?1?1?1 ?1?1?1?2
./oclHashcat.bin -1 ?d?l?u -2 wxyzABCD -o [output-file] [hashes-file] ?1?1?1?1 ?1?1?1?2
./oclHashcat.bin -1 ?d?l?u -2 EFGHIJKL -o [output-file] [hashes-file] ?1?1?1?1 ?1?1?1?2
./oclHashcat.bin -1 ?d?l?u -2 MNOPQRST -o [output-file] [hashes-file] ?1?1?1?1 ?1?1?1?2
./oclHashcat.bin -1 ?d?l?u -2 UVWXYZ -o [output-file] [hashes-file] ?1?1?1?1 ?1?1?1?2

Notice how the first custom charset deals with the whole charset and the second one deals with just the 8 parts of the charset.