On Mon, Sep 9, 2013 at 11:46 AM, Paul Wouters <paul@xxxxxxxxx> wrote: > [not speaking for Red Hat] > You seem to believe only valid legal claims can put Red Hat in court. Of course not. Though I'm not aware of anyone making any claims at all over basic non-specially optimized ECDH on prime fields. Perhaps RedHat is, though if certicom/rim is out patent trolling on the basic stuff it would be a shame to keep it a secret: They should take the goodwill loss they deserve if they're going around claiming to own techniques published in the mid 80s. You're going to have a lot of software to remove if the _possibility_ of someone putting RedHat in court is the bar here. There are a _LOT_ more patents on compilers than on elliptic curve cryptography. Or just patents on simple arithmetic optimizations, lets see US6073150 assigned to Sun. This one patents computing the absolute value of a signed number using masking by sign extension: E.g. Set mask = x>>(sizeof(x)*sizeof(char)-1); absx = (x^mask)-mask. Oh looky looky, GCC in Fedora 19 on x86_64 compiles "int x; x = abs(x);" to this: sarl $31, %eax xorl %eax, -4(%rbp) subl %eax, -4(%rbp) Good thing nothing in Fedora uses abs() and that Sun's patent's would never be held by a potentially hostile company so you don't have to depend on the fact that this technique was published eons before the patent (http://web.archive.org/web/19961201174141/www.x86.org/ftp/articles/pentopt/PENTOPT.TXT), since that the invalidity of the claim can't be ensured to keep RedHat out of court. ... And this is an example where we actually do the stuff that is patented. I do not believe there are any granted but invalid patents that would preclude using basic ECDH over prime fields. Maybe there are and RedHat has heard of some, but if so the world would certainly like to know that someone actual had a concrete risk here and this wasn't someone just pattern matching "ECC = Patents ZOMG!" in a way that they don't go "Compilers = Patents ZOMG!". -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
