Question

How can I make bruteforce password recovery software in delphi using with parallel computing technologies for md5 Algorithms!

Can someone tell me some advise?

Thanks

Answer 1

Parallel computing makes sense in today’s day and age due to most of our CPUs having multiple cores.

However, your performance is not a one to one relationship with the number of threads. You’ll most likely want just one or two threads per core.

You can use TThread class to create multiple threads in Delphi.

Indy has a MD5 hash function in the IdHashMessageDigest unit.

Make sure that you know the exact algorithm, including the use of any salt, before you attempt to reverse an MD5 hash through brute force.

If there was no salt used, I think there are probably rainbow tables available for MD5 on the web already, where you can just do a search.

You’ll most likely want to try a dictionary attack prior to trying every possibility. There are many dictionaries available for download on the Internet, easily found on Google.

With more specific questions, we can give more specific answers.

Edit

To create a grid computing system, whereby you distribute the work to many computers, you’ll need a central management server that doles out pieces of the work to the other computers. If the results aren’t returned within a certain time threshold, then you put it back in the queue.

You’ll need to build a simple framework where you can pass in a few parameters that represent a work load to each client, upon request. Perhaps it’s a range of values to try.

The client should contact the server to receive a piece of work, and it always report back when it has finished the work, or perhaps immediately if it makes a hit.

If you have enough computers, consider each client building a local rainbow table for each possible salt, utilizing the storage from each client.

Example of work queue

Here’s an example of a piece of work that would be sent as a parameter, and most likely stored in a database.

You want to attack the hash SLDFJIJ44adsf.

Here are the tables:

Hashes
----------------------------
TargetHash      Answer
----------------------------
SLDFJIJ44adsf   NULL   

Work
----------------------------
TargetHash      Type        RangeBegin      RangeEnd    DateAssigned
----------------------------
SLDFJIJ44adsf   Dictionary  aardvark        beaver      2011-12-16
SLDFJIJ44adsf   Dictionary  beavis          zoology     2011-12-16
SLDFJIJ44adsf   Brute       aaaa            ZZZZ        2011-12-16
SLDFJIJ44adsf   Brute       aaaaa           MZZZZ       2011-12-16