crypto backdoors = terrorisms free reign

Hadmut Danisch hadmut at danisch.de
Sun Sep 16 13:08:31 EDT 2001


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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