Re: [gentoo-dev] [PATCH v2 07/11] glep-0063: Allow ECC, curve 25519 keys

[Joshua Kinard]

On 7/4/2018 6:23 AM, Michał Górny wrote:
> Optionally allow using ECC, curve 25519 keys.  We already have
> developers using those keys, and given that they are supported
> by GnuPG 2.2, there's probably no reason to ban them.  However, they're
> not recommended due to interoperability issues.
> ---
>  glep-0063.rst | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/glep-0063.rst b/glep-0063.rst
> index 6dc4ce5..ab7cb79 100644
> --- a/glep-0063.rst
> +++ b/glep-0063.rst
> @@ -33,6 +33,8 @@ v1.1
>    The larger recommendation was unjustified and resulted in people
>    unnecessarily replacing their RSA-2048 keys.
>
> +  Minimal specification has been amended to allow for ECC keys.
> +
>  Motivation
>  ==========
>
> @@ -64,6 +66,8 @@ not be used to commit.
>
>     b. RSA, >=2048 bits (OpenPGP v4 key format or later only)
>
> +   c. ECC, curve 25519
> +
>  3. Key expiry: 5 years maximum
>
>  4. Upload your key to the SKS keyserver rotation before usage!
>

Add a minimum key size here for ECC.  They have different bit sizes than
classic DSA/RSA keys.  A quick read indicates that a 224-bit ECC key is roughly
equivalent to a 112-bit symmetric key, which is what a 2048-bit RSA key is
equivalent to, so the logical minimum for ECC looks like 'nistp256'.  The
maximum is 521-bits on ECC (nistp521).

Also move the mention of Ed25519 keys to their own bullet and clarify that they
don't allow for a key length, as I think that's hardcoded in some capacity.

-- 
Joshua Kinard
Gentoo/MIPS
kumba@g.o
rsa6144/5C63F4E3F5C6C943 2015-04-27
177C 1972 1FB8 F254 BAD0 3E72 5C63 F4E3 F5C6 C943

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