/passphrase-cracking

Primary LanguageTeXGNU General Public License v3.0GPL-3.0

Passphrase Cracking

In this repository you will find all relevant files for a research project into probabilistic passphrase cracking, done by Luc Gommans in January 2018, with Radically Open Security, for the study Security & Network Engineering (SNE/OS3) (RP1).

The final paper can be found in paper/paper.pdf. Our n-gram cracker code and trained n-gram files in ngram-cracker/. Everything is available under GPLv3.

Practical Passphrase Cracking

The conclusion of our research is that, so far, a hybrid dictionary attack is the most effective method of cracking passphrases, as described by Hugo Labrande in his paper (see our paper for the reference). We reproduced most of his research and are now publishing a dictionary which can be used for the purpose, because collecting it was quite a pain :-)

You can find the dictionary in rosbot-integration/dict-wikiphrases.xz.partX. It is in two parts because Github does not allow files >100MiB, you can reassemble and decompress it using:

cat dict-wikiphrases.xz.part{1,2} | xz -d > dict-wikiphrases

It is 690MiB uncompressed.

Now that you have the dictionary, you'll want to add at least our mangling rules (and perhaps some of your own), which can be found in the same folder: rosbot-integration/hashcat-ruleset-X.

Now run hashcat with the appropriate -m value (for example, for SHA1, use 100):

hashfile=your-hashes.txt
hashcat -m 100 -r hashcat-ruleset-1 -r hashcat-ruleset-2 -r hashcat-ruleset-3 $hashfile dict-wikiphrases

With this dictionary and rulesets, it should run in under 20 minutes on a modern system. In the LinkedIn hashdump, for example, this should crack around 2.3 million passphrases!