Re: How secure is SSL emails?

From: Guy Macon (http://www.guymacon.com)
Date: 06/29/04 

Date: Mon, 28 Jun 2004 18:52:11 -0700

Peter Fairbrother <zenadsl6186@zen.co.uk> says...
>
>Guy Macon wrote:
>
>> Peter Fairbrother says...
>
>>> I don't use RC4 in my designs. I won't even consider it. I don't use RotN
>>> either, and for exactly the same reason. Because they aren't 100% secure in
>>> all circumstances, and I can get a cipher that is.
>>>
>>> Then I don't have to worry about whether the cipher fits the threat model -
>>> which can change.
>>>
>>> I can spend my time worrying about other things instead :).
>>
>> Unless you are using OTP, I don't see how you can possibly justify saying
>> "100% secure in all circumstances [...] I can get a cipher that is." How
>> could you possibly know that this is so? WWhat evidence do you have?
>> What is your reasoning?
>
>There is of course no cipher such that we _know_ that it is secure in all
>circumstances - but there are some ciphers that we can and do _assume_ are
>unconditionally secure.
>
>Actually, such a cipher might be just around the corner, but that's another
>story.

I am having trouble reconciling "Because they aren't 100% secure in
all circumstances, and I can get a cipher that is" and "There is of
course no cipher such that we _know_ that it is secure in all
circumstances". Which is it?
  

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