zfec is much, much faster than par2: http://allmydata.org/trac/zfec
Tahoe-LAFS uses zfec, encryption, integrity checking based on SHA-256, digital signatures based on RSA, and peer-to-peer networking to take a bunch of hard disks and make them into a single virtual hard disk which is extremely robust: http://allmydata.org/trac/tahoe
Thanks for the kind words about Tahoe. I'm one of the architects. We have indeed done a lot of work on security in Tahoe, and the contributors to Tahoe do collectively have a lot of expertise in security engineering.
However, we know that security is awfully hard, and there's nothing like open peer review to shake out the subtle problems.
That's why we are running the "Hack Tahoe!" contest. If you can find a security hole that we overlooked, then you'll receive acclaim, a customized t-shirt with your exploit printed on the front, and a picture of your smiling face on our Hall of Fame.
In 1914, the first crossword puzzle was printed in a newspaper. The creator received $4000 down ... and $3000 across.
