Re: [Ntp] Antw: [EXT] Re: Post NTS, Is shared key authentication interesting?

Harlan Stenn <stenn@nwtime.org> Wed, 27 May 2020 13:37 UTC

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From: Harlan Stenn <stenn@nwtime.org>
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Date: Wed, 27 May 2020 06:37:35 -0700
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Subject: Re: [Ntp] Antw: [EXT] Re: Post NTS, Is shared key authentication interesting?
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On 5/27/2020 6:33 AM, Salz, Rich wrote:
> 
>>    sending an error message that something with the crypto was bad
>     it a bad idea. You should pretend that everything was ok. An
>     attacker should not be able to see the difference between an ok
>     and a not ok message. Look for instance at the TLS RFCs what they
>     write about a Bleichenbacher attack.
> 
> Yes!
> 
> This is known as an oracle, and from this kind of thing, it is possible to do pretty fine-grain timings and figure out keys.  This is often surprising to folks, but look up "Lucky Thirteen" as an example. 

So where is this attacker?

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-- 
Harlan Stenn <stenn@nwtime.org>
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