undefined | Better HN

0 pointstptacek12y ago0 comments

EncFS is a FUSE filesystem. There is no reason for it to use sector-level encryption. It's format-aware. It can do fully randomized encryption and provide strong authentication. However, someone involved in EncFS did propose switching to XTS. Which is actually what prompted me to write this article.

0 comments

2 comments · 1 top-level

makomk12y ago· 1 in thread

Oh. Oh dear. The reason that EncFS were considering switching to XTS is because their last security audit suggested it[1], probably with good reason. Remember that many applications also expect fast sector-level random read and write access to files; add in the potential for power-failure-related data corruption and missing writes, and you can't really do much better than XTS. (At least not whilst relying on a normal filesystem as your backend; ZFS can probably do more.)

[1] https://defuse.ca/audits/encfs.htm

tptacekOP12y ago

No, this isn't true at all. If you don't have the physical disk geometry problem, you shouldn't be using XTS. In fact, the whole article is about exactly this point.

In particular: you do not need XTS to get "fast random read and write access".

Taylor's a smart guy. I'm pretty sure he's wrong about this (although maybe he knows something applicable about EncFS that I don't know). If I thought that there was no way any smart person could make the mistake of applying XTS somewhere it didn't belong, there'd be no point to writing the article. :)

j / k navigate · click thread line to collapse