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Date: Wed, 18 Nov 2020 06:47:48 +0100 (CET)
From: Dietmar Maurer <dietmar@proxmox.com>
To: Proxmox Backup Server development discussion <pbs-devel@lists.proxmox.com>, 
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Subject: Re: [pbs-devel] [PATCH proxmox-backup 0/7] add,
 persist and check key fingerprint
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> On 11/18/2020 6:27 AM Dietmar Maurer <dietmar@proxmox.com> wrote:
>=20
> =20
> Do we really need/want a 256bit long fingerprint?
>=20
> I thought 64bit (or maybe 32bit) would be large enough?
> If not, why does it have to be that large?

some quick math:

max keys a user generate in his live: 1024 (2=C2=B9=E2=81=B0)

so the likelihood of a 32bit fingerprint clash is=20

W =3D 1/2^=C2=B2=C2=B2   (1/4Millions)

which is, unlikely, but possible.

But with 64bit it is extremely unlikely (1/2=E2=81=B5=E2=81=B4).