Is a one pass with DBAN good enough?
 

Dear LQ,

I saw an article about securely wiping hard dries for resale or disposal. Anyway, in the article it mentioned that a one pass wipe with DBAN is good enough. Do you agree with this?

I personally use bcwipe and then encrypt for good measure when throwing my hard drive away. What do you use to securely erase your drive?

I do a single dd dump from /dev/zero to wipe drives if they're going in for RMA or similar. I don't feel multiple passes would be worth it, because anything sensitive on the drive will most likely be in an encrypted volume anyway. If they're going to be disposed of I destroy them with a hammer...it's both effective and fun!

A 45 slug.

Yeah, who wants to do multiple passes on a terabyte drive or larger? I don't.

Both DBAN and bcwipe offer a lot of different options which could solve your problem. If you are only doing one pass, the question is not which brand, but which data stream, if any, renders the drive unreadable even by unconventional means.

I would put my faith in the theory that the best spatial coverage (overwriting magnetization deep into the platter and broad across the track) is obtained with data streams that have a broad spectrum, like pseudo-random numbers.

Since you ask, I use /dev/urandom but speed it up with this trick, which is cryptographically weak but at least covers the spectrum.