Re: Proposal: Remove MKCRYPTO_RC5

Just curious...

Without considering the expiry date of the patents themselves, I was 
under the impression that RC5 and RC6 were registered trademarks.  So, 
do we have any issues from a trademark perspective?



On Fri, 5 May 2017, Joerg Sonnenberger wrote:

> On Fri, May 05, 2017 at 05:49:39PM +0000, Taylor R Campbell wrote:
>> - It is (still!) patented in the United States, so it has only ever
>> been a default-off option that we go to extra work to implement.
>
> This part isn't clear to me. According to
> http://jce.iaik.at/sic/Sales/Patent_Issues_Algorithms#RC5
> there are three possible patents relevant to RC5. Looking at the
> details and comparing with other sources, 5,724,428 is the main patent.
> 5,835,600 might be relevant, 6,269,163 is clearly RC6 (and talking about
> RC5 quite a bit). Of those, '428 was filed on Nov 1, 1995 and Apr 21,
> 1997.
>
> According to:
> https://www.uspto.gov/patent/laws-and-regulations/patent-term-calculator#heading-5
> for patents filed after June 7, 1995, the term ends twenty years after
> the initial filing date. As such, both patents would seem to have
> expired.
>
> Based on that, I would suggest to drop the option and just include RC5
> unconditionally.
>
> Joerg
>
> !DSPAM:590d7d9a66488531485152!
>
>

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