On Sun, Sep 21, 2008 at 3:23 AM, Martin Geisler <[EMAIL PROTECTED]> wrote: > Calling a ElGamal function in NaCl would be very cool and probably a bit > faster since you wont have to do all the tuple packing and unpacking > that you do in the Python version.
NaCl has support for a primitive called a 'box'. The boxing function takes these inputs: * The message * An nonce * The recipient's public key * The sender's private key Note that requiring the sender's private key makes this different from most public key encryption functions. The unboxing function, symmetrically, requires the sender's public key. (This boxing function may be viewed as a encrypt+sign operation.) If this fits your model, then NaCl already contains everything you need. In this case, the underlying primitive is not ElGamel, but Diffie-Hellman. The two keys are combined with ECDH and the nonce (which both sides must know, but need not be secret) diversifies the long-term shared key into a per-message key. Based on timings for the x86-64 ECDH implementation, which I wrote, 4*10^6 operations should take about 880 seconds for a short message. AGL -- Adam Langley [EMAIL PROTECTED] http://www.imperialviolet.org _______________________________________________ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
