Need To Decrypt an md5 Hash? Try Some Free Rainbow Tables

If you’re like me, remembering fifty or more unique passwords is sometimes frustrating. I refuse to use any sort of password management system, and writing them down defeats the purpose of even having a password. Some prefer using the same password for everything, but if one account is compromised, the rest will probably soon follow. The most recent circumstance for me was a forgotten vBulletin admin password. Since reinstalling wasn’t an option, that left me with the option of manually updating the database, which didn’t work. Ok, so now what? Crack the md5 hash with Rainbow Tables.

Why Use Rainbow Tables?

Rainbow Tables, compared to brute forcing, is much faster. The time consuming part is actually generating the tables used to run decrypted hashes against, but once generated, they’re good forever. The Rainbow Tables project page provides a lot of instructions and configuration examples. One of the tables was able to crack the following passwords in only a few minutes.

N73k_a7()TUBoK

PrFa$=ptRcb^__ z

%G)r*EW&2nk#

cjST$=W0U*-5CH

(zw= ijV$i*vEX

How rad is that? Table generation can take days, even weeks, and will consume pretty large quantities of hard drive space depending on the configuration options, but there is an alternative.

Collaborative Rainbow Table Generation

Similar to the SETI project, Free Rainbow Tables is a distributed rainbow table generation project that combines the computing power offered by members. Once registered, the free client will put your CPU to work by generating chains for the project. In return, members are able to use the 100+ gigabytes worth of tables for their own decryption needs. The online system makes submitting your encrypted hashes easy, and the hash management portion of the site lets you know when your hash is being searched for. Surprisingly, the success rate for decryption is pretty low with 11,523 (47%) hashes at the time of writing. But this is definitely something worth having in your arsenal when used with locally generated tables.

As of right now I’m approaching 10 gigabytes worth of locally stored tables. If you’re interested in exchanging tables, just let me know via comment or email.