Dan Bernstein's CurveCP in experimental release

The short summary of CurveCP is that it's essentially an encrypted and authenticated TCP[1] (tunneled over UDP). The main selling point is that it's fast, partly by clever protocol design and mostly by use of highly-efficient elliptic curve cryptography.

It's really cool, but sadly probably doomed to obscurity - unencrypted TCP/SSL/IPSec are "good enough".

[1] Actually, Dan Kaminsky stated that it's perfectly usable as a UDP replacement.

Text of his announcement:

Hi everybody,

I've posted information about CurveCP at http://curvecp.org; and today's release of NaCl includes command-line curvecpclient and curvecpserver tools. There are many reasons that this curvecpclient+curvecpserver software isn't ready for users yet---among other things,

  * the software hasn't gone through anywhere near my usual levels of
    testing and security review;
  * the software prioritizes simplicity over efficiency in several
    ways, missing some of the speed that CurveCP can provide; and
  * the software handles only CurveCP, without HTTPCurve, SMTPCurve,
    etc.

---but if you're a programmer interested in CurveCP then I think this software is a reasonable starting point for experimentation and further development.

---D. J. Bernstein Research Professor, Computer Science, University of Illinois at Chicago

Here's Dan Kaminsky's thoughts on the proposal, fwiw, as of a month or so ago: http://dankaminsky.com/2011/01/05/djb-ccc/#curvecp

And NaCl now has signatures based on curve25519: crypto_sign_edwards25519sha512batch.