Hello Johnny,
On Sat, 2011-12-31 at 08:13 -0600, Johnny Hughes wrote:
http://www.gtri.gatech.edu/casestudy/Teraflop-Troubles-Power-Graphics-Proces...
http://www.pcpro.co.uk/blogs/2011/06/01/how-a-cheap-graphics-card-could-crac...
These articles fail to clarify even the most basic of assumptions they make. I can only guess the numbers relate to the cracking of MD5 hashes (salted or unsalted?) and access to the /etc/shadow file.
On CentOS-6 password hashes are no longer stored as MD5, but as SHA-512 hashes. Apparently the SHA hashing algorithms as used by Red Hat have a configurable iterator count much like bcrypt ( http://en.wikipedia.org/wiki/Crypt_%28Unix%29 "SHA2-based scheme").
Also, the only way for an attacker to have access to /etc/shadow is to already have root access to your system in which case you are already faqed.
Imo the weakness of MD5 hashes is more of a concern for web applications where an attacker might gain access to (part of) your database via f.e. SQL injection. This is why a proper web application will use a bcrypt hash to store passwords. As the amount of iterations bcrypt uses is configurable the algorithm can scale with increasing processing power.
Regards, Leonard.