[9327] in cryptography@c2.net mail archive
Re: crypto backdoors = terrorisms free reign
daemon@ATHENA.MIT.EDU (Hadmut Danisch)
Sun Sep 16 15:28:16 2001
From: Hadmut Danisch <hadmut@danisch.de>
Date: Sun, 16 Sep 2001 19:08:31 +0200
To: Amir Herzberg <AMIR@newgenpay.com>
Cc: cryptography@wasabisystems.com
Message-ID: <20010916190831.A3911@danisch.de>
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On Sun, Sep 16, 2001 at 10:00:21AM +0300, Amir Herzberg wrote:
>
> Suppose by law, everybody can use GAK encryption alg, say `GEEK`. Attacker
> wishes to use non-GAK algorithm, say `TRICK`. GEEK has a distinguisher
> module available to NSA which outputs GEEK or SUSPECT for encrypted data
> (using GEEK or any other algorithm, respectively).
>
> Attacker encrypts his data with TRICK and then with GEEK. So this is validly
> GEEK encrypted data. Until the NSA tries to decipher it, it looks fine.
>
Obviously.
You can make it even more simple:
I send you one bit, e.g. a "1".
Was this plaintext or a ciphertext encrypted with a forbidden cypher?
Well, this leads to the conclusion that you have to forbid
sending 1s. Restrict communication to sending 0s. Hopefully nobody
discovers, that a "0" could be an encrypted "1"...
Hadmut
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