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Re: [Cfrg] Backup ciphersuites in the event of an ECCpocalypse

Johannes Merkle <johannes.merkle@secunet.com> Tue, 16 June 2015 15:15 UTC

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Date: Tue, 16 Jun 2015 17:15:04 +0200
From: Johannes Merkle <johannes.merkle@secunet.com>
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To: "Salz, Rich" <rsalz@akamai.com>, Tony Arcieri <bascule@gmail.com>, "cfrg@irtf.org" <cfrg@irtf.org>
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Subject: Re: [Cfrg] Backup ciphersuites in the event of an ECCpocalypse
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Salz, Rich schrieb am 04.06.2015 um 02:33:
>> Should there be backup algorithms in the event of some revolutionary innovation that breaks all known curves or all curves presently in use?
> 
> No.  It is trying to solve a worry about the future with a hope.
>

We have the scenario of someone building a quantum computer. In this case, not only ECC is broken but RSA and FFDH, too.
Although I can't imagine that this will happen soon, it's better to be prepared.


> How do you know a backup is any better?  And, if it is, why is it a backup and not the primary choice?
> 

There are many schemes believed to be resistant to quantum computers, including hash-based signatures where the security
can be based on any secure hash function.
https://datatracker.ietf.org/doc/draft-huelsing-cfrg-hash-sig-xmss/
https://datatracker.ietf.org/doc/draft-mcgrew-hash-sigs/

Of course, almost all Post-quantum schemes have very large keys making them not the primary choice today.

-- 
Johannes

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