Re: [Cfrg] Elliptic Curve patents

Dan Brown <> Fri, 07 October 2016 12:32 UTC

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From: Dan Brown <>
To: Michael Scott <>, "" <>
Thread-Topic: [Cfrg] Elliptic Curve patents
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Subject: Re: [Cfrg] Elliptic Curve patents
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how are "strong" primes defined here?

From: Michael Scott
Sent: Friday, October 7, 2016 5:57 AM
Subject: [Cfrg] Elliptic Curve patents

I was just doing some checking on the status of patents as applicable to Elliptic Curve Cryptography, and I came across the very impressive patent portfolio of one Bernd Meyer.

See for example this one..

Cryptographic method with elliptical curves<>
Patent number: 8582761
Abstract: A method determines an elliptical curve, suitable for a cryptographic method. An elliptical curve to be tested is prepared. The order of a twisted elliptical curve associated with the elliptical curve to be tested is determined. It is automatically checked whether the order of the twisted elliptical curve is a strong prime number. If the order of the twisted elliptical curve is a strong prime number, the elliptical curve to be tested is selected as an elliptical curve suitable for cryptographical methods.
Type: Grant
Filed: March 6, 2007
Date of Patent: November 12, 2013
Assignee: Siemens Aktiengesellschaft
Inventors: Jean Georgiades, Anton Kargl, Bernd Meyer

Now I know that no-one here is a lawyer. But I would read this as suggesting that Siemens holds a patent on twist secure curves (like GoldiLocks).

Tell me it ain't so. And not just that, if you look at the full portfolio, many other commonly used techniques for ECC are also covered.

Mike Scott