Re: [Acme] Fwd: New Version Notification for draft-mattsson-acme-use-cases-00.txt

Phillip Hallam-Baker <> Tue, 10 March 2015 12:04 UTC

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Date: Tue, 10 Mar 2015 08:04:08 -0400
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From: Phillip Hallam-Baker <>
To: Bernd Eckenfels <>
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Subject: Re: [Acme] Fwd: New Version Notification for draft-mattsson-acme-use-cases-00.txt
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On Mon, Mar 9, 2015 at 8:04 PM, Bernd Eckenfels <>

> Hello,
> I don't think it is a good idea to add any functionality which tries to
> move/copy the private key (and with some hardware protection it should
> also not possible). And it is not really needed. Just request a new one.
> The ACME credentials might be transported, but I am not sure you want
> to do that via untrusted (ACME) servers...
> Gruss
> Bernd

Copying a private key is not a use case, it is (or isn't) a requirement.

A use case is 'Fred wants to start a new server and avoid re-validation'

There are use cases in which it makes sense for private key material to
come from a third party. In particular you don't want to be generating RSA
key pairs on a machine in the cloud that is shared with another party.

A similar problem comes up with stored encryption keys. Alice wants to be
able to read her email on her iPhone and her Surface tablet. So she needs
both to have the same decryption key.

Whether these use cases are in or out of scope is another matter. But
usually you want to discuss the use case and decide according to how much
implementation complexity the solution adds.

OBDisclaimer: Comodo has pending IPR claims that cover new approaches to
solving some of these use cases. At this point all rights are reserved.