Pure python crypto

[Michael Gilfix]

On Thu, Apr 18 @ 03:02, Paul Rubin wrote:
> Might as well.  My address is above.  What's the encryption speed?

  Haven't done any throughput testing on it yet. I just finished it
over the weekend but then exams took over :)

> > > FWIW, I coded RC4 in Python a while back and if I remember correctly,
> > > got about 100k/sec throughput on a P3-750.  That's sort of marginal
> > > for (say) sftp over ADSL.  Using the SHA-OFB hack that I described,
> > > I got about 400-500k/sec.  
> > 
> >  Do you still have a copy of this? I would be nice to assemble a suite
> > that can be used to create a pure python implementation of SSH (which
> > could also use wrappers to C implementations that exist as well).  I
> > wish I had a better idea of what was out there module-wise though.
> 
> I'll take a look, I probably still have it.  I only spent a few
> minutes coding it anyway, so can do it again if needed.  If coding RC4
> is an obstacle to you though, I don't think you're going to finish
> implementing SSH ;-).  Anyway, after coding RC4, I saw how much slower
> it was than SHA-OFB, so I stopped caring about it and may have trashed
> the implementation.

  Haven't looked into implemented RC4 yet :) I was looking at DES but
there are so many different ways to approach implementation...

> With luck, future versions of Python should include a DES/3DES module,
> so an SSH package can use that.

  Agreed. They do exist with C wrappers. I'll have to wait until after
exams though, so probably sometime in May before I really consider it.

              -- Mike

-- 
Michael Gilfix
mgilfix at eecs.tufts.edu

For my gpg public key:
http://www.eecs.tufts.edu/~mgilfix/contact.html