At 01:00 PM 98/05/05 -0400, Rich Ankney wrote:
Hitachi claims to have a patent covering SHA1.
This seems rather odd. Is it on a particular hardware implementation
of SHA1? Do you have a patent number for this?
No, but you could look up the IBM patent server. The Hitachi patent was
mentioned in a thread of the P1363 discussion list. I'll notify you if I
discover the patent number and/or its exact claims.
I don't think it ever went to court, but no one seems to be getting sued
for using DSA...
So it was settled before going to court; someone (possibly Schnorr himself,
but I'm not sure) did raise the issue of patent coverage (unsuccessfully).
ECDSA in particular is not patented. Certicom has patented various
hardware tricks to implement EC over GF(2^m). Certicom also has
a patent on the MQV variant of Diffie-Hellman which can be used over
EC, but has granted a royalty-free license for its use.
I wouldn't be so sure about this. A fully compliant implementation must
support point compression, and Certicom has filed a patent on this.
As for the royalty-free license, Don Johnson of Certicom sent me personal
mail saying that there is a "small" fee to be paid for the set of Certicom
patents (one dollar per copy of the product using any of them). This
includes the MQV scheme.
Cheers,
Paulo barreto.