Is overwriting files more than one time unnecessary?

[Audio]

Is overwriting files more than one time unnecessary? I've heard that the government only requires multiple passes just incase someone can recover overwritten files in the future and that only one pass is needed.

[street011]

euh.. usualy one overwrite is enough, that is when the patern is random.

the point is that when a stream of data is written it wont be written on the disk EXACTLY the same position as the previous write, which theoreticaly makes data recoverable after overwrite.

afaik it's never successfully been done. and it gets even harder when the recoverable data is bigger then only a few bytes.

check out the truecrypt forums, there's a lot info there.

[Audio]

Will do, thanks street011