🚀 go-pugleaf

In article <scs.724599694@hela.iti.org>, scs@iti.org (Steve Simmons) writes:
> ckd@eff.org (Christopher Davis) writes:
> 
> I just spoke to our corporate lawyer who is an expert in such stuff.
> U.S. patents expire 17 years after issue, with no renewal.  Thus if
> it's been out there 15 years, it's only go two years to go.  Wait
> it out.

Note:  date of *issue*.  Here are some important public-key patents:

4,200,770	Hellman, Diffie, and Merkle
Filed Sept 6, 1977; issued Apr 29, 1980.
Has a broad claim on key exchange mechanisms (i.e., Diffie-Hellman)

4,218,582	Hellman and Merkle
Filed Oct 6, 1977; issued Aug 19, 1980
Has a broad claim covering public-key cryptography; uses the knapsack
system as an example.

4,405,829	Rivest, Shamir, Adleman
Filed Dec 14, 1977; issued Sept 20, 1983
The RSA cryptosystem, of course.  Note how long it took that patent
to be issued -- and hence how much longer till it expires.