Yubico Forum

Re: ECC key length?

2016-06-21T14:30:47+01:00

Quote:

YubiKey 4 only supports RSA keys

Thanks. That is unfortunate!

Statistics: Posted by jcross — Tue Jun 21, 2016 2:30 pm

Re: ECC key length?

2016-06-14T22:02:40+01:00

Both PIV and OpenPGP use the NIST curves.

Section 3.1 of NIST Special Publication 800-78-4 requires that ECC keys for PIV (FIPS 201) be generated from the P-256 or P-384 curves. Thus, the blog post’s claim of 521-bit ECC keys was probably in error, since a smart card using a P-521 key would not be compliant.
Section 12.1 of RFC 6637, the proposed ECC extension to OpenPGP, prescribes P-256, P-384, and P-521. Unfortunately, YubiKey 4 only supports RSA keys.

Statistics: Posted by larryv — Tue Jun 14, 2016 10:02 pm

Re: ECC key length?

2016-06-11T18:09:41+01:00

Thanks for pointing that out.

Is this just for PIV or also OpenPGP keys that use ECC?

Statistics: Posted by jcross — Sat Jun 11, 2016 6:09 pm

Re: ECC key length?

2016-06-11T17:42:33+01:00

I can’t speak to which figure is correct, but “521” is probably not a typo. The NIST-recommended elliptic curve for 256-bit equivalent security is called P-521 and is based on a 521-bit prime.

Statistics: Posted by larryv — Sat Jun 11, 2016 5:42 pm

ECC key length?

2016-06-06T15:06:08+01:00

Hello,
On this page, Yubico indicates that the YubiKey 4 support up to 521 bit ECC:

Quote:

"The YubiKey 4 is a single-chip design without a Java Card/Global Platform environment, featuring RSA with key lengths up to 4096 bits and ECC up to 521 bits."

But on this page it says 384.

I am thinking that they both might be wrong as 512 seems much more likely.

Which is it?

Thanks.

Statistics: Posted by jcross — Mon Jun 06, 2016 3:06 pm