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Re: [Cfrg] Encrypting a known short text

Greg Rose <ggr@seer-grog.net> Fri, 22 September 2017 16:31 UTC

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From: Greg Rose <ggr@seer-grog.net>
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Date: Fri, 22 Sep 2017 09:31:49 -0700
Cc: Greg Rose <ggr@seer-grog.net>, Cfrg <cfrg@irtf.org>
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To: Erik Andersen <era@x500.eu>
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Subject: Re: [Cfrg] Encrypting a known short text
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No. Availability of the plaintext to the attacker is a standard assumption.

Greg.

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> On Sep 22, 2017, at 9:19 , Erik Andersen <era@x500.eu> wrote:
> 
> Suppose we have a protocol, where everything is encrypted.
>  
> If the clear (short) text may be guessed by an attacker (it could be an ASN.1 NULL), do we then have a security issue, where the encryption key could be revealed? 
>  
> Best regard,
> Erik
>  
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