Re: building compatible zip files "by hand" that are encrypted and compressed

Ed,

> I didn't think there were variants of AES, other than
> the key length and the block size.  It sounds like you
> are saying either:

> 1) The actual AES encryption algorithms are different
> between PKZip and WinZIP, or
> 2) PKZip and/or WinZIP use the same AES algorithm but
> are somehow hashing or modifying the key (as specified
> by the user), and the two don't use the same hashing
> or modification? 

I haven't paid all that much attention because, frankly, I don't
care.  My vague recollection was that at most one of them is using
AES, and how you apply that to the data stream that goes into the
zipfile format certainly involves more than just the AES algorithm
itself.  But maybe it's done in "the straightforward way" (whatever
that is) and can be made interoperable.

The upshot is that you're asking lots of questions about proprietary
software on an open-source list.  If you must know the answers to 
these questions, go ask the proprietary software vendors themselves.
Or do the experiment.  But you're wasting your time here.

> Are the actual differences between AES-encrypted ZIP
> archives created by PKZip and WinZIP documented
> anywhere?

http://www.pcworld.com/news/article/0,aid,110820,tk,dn052103X,00.asp

Greg