Published Mon 21 November 2016 by Daniel W
Cracking WPA/WPA2 Hashes using GPUs
Recently I have been investigating the most effective way to crack WPA passkeys, and I wanted to know - what is the most cost effective method for hashing the key; purchasing a GPU(s) or using a cloud based service such as AWS.
I first began by capturing the 4-way handshake from the target AP using Kali Linux and
airmon-ng, and stored this on my computer. I performed my baseline crack using a conventional system with the following specifications:
Using hashcat as my hash cracking software, the crack was successful using a brute-force keyspace attack with an approximate cracking time of 12 hours, and an actual cracking time of approximately 3 hours.
The computer was able to sustain approximately 220kH/s.
Using the approximate recommend retail value of the cards I’ve listed above, it seems that the GTX 980 is perfectly positioned as the best ‘bang for buck’ card I’ve investigated, with other newer cards not providing enough of an increase in performance in this application to offset their significantly more expensive cost.
A second alternative would be using a server from AWS in the g2.8xlarge combination to perform incidental cracks, but in this case the job would have cost approximately $31AUD it’s up to the user to decide whether that is worthwhile or not.