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When an elliptic curve-based cryptosystem is deployed, a single set of public parameters (consisting of a particular elliptic curve over a finite field as well as a generator of a prime order subgroup of its group of points) is typically shared across all users.

Some of these public parameters are standardized in some form. The best known ones are NIST-approved curve parameters, described as part of the FIPS 186-{2,3} standard, but there are others. For example, a French agency recently released a set of parameters recommended for local security applications (possibly over concerns re the security of curves over the very special base fields used by NIST?—they didn't say).

Is a list of such curve parameters compiled somewhere? Do you know any aside from the previous ones?

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The French authorities gave the following rationale for their FRP256v1 curve: "The proposed parameters correspond to a randomly generated curve, selected as to obey usual security criteria" (my emphasis); I infer that (at least one of) the motivation was to avoid a special field as in P-256 of FIPS 186-3. The "usual security criteria" are likely those in RGS annex B1, section – fgrieu Feb 21 '12 at 11:50
One can infer that indeed, but on the other hand, the Digital Signature Standard says that NIST-approved curves are randomly generated (and even “provably” so!) in the sense that the curve coefficients are chosen using a hash function (even though the base fields are quite special). So it seems difficult to tell what exactly randomly generated means in this context. – Mehdi Tibouchi Feb 22 '12 at 2:22
up vote 6 down vote accepted

There are a few more standards, with (sometimes) overlapping sets of parameters:

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Very useful, thanks. – Mehdi Tibouchi Feb 22 '12 at 2:14
Actually there is considerable overlap: all 15 FIPS 186-2/3 curves are part of the 20 curves that X9.62 lists in its annex L; and all these 20 curves are part of the curves listed in SEC 2. The Brainpool curves are (deliberately) separate. – Thomas Pornin Feb 26 '12 at 1:57
Also, the AACS standard (protection on HD-DVD and Blu-ray discs) uses ECDSA in their own curve (see this document)‌​, page 10). When Sony designed the protection system for the PS3, they defined no less than 64 new curves (and they totally botched their ECDSA implementation, but that's another story). – Thomas Pornin Feb 26 '12 at 2:00

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