Hi,

Terje Elde wrote:
> Reverse is also mostly (but not certainly); If AES is secure, there’s a good 
> chance that Camellia is as well.

I would not totally agree there. This comes back to my point that
there's far less academic research on CAMELLIA than on AES - for
non-public research: we just don't know.

> 
> The one thing that worries me with the discussion of removing Camellia, is 
> that arguments for are almost always focused exclusively on a 
> cryptographic/mathematic perspective.  The arguments are often true, valid 
> and good, but they’re also narrow in scope.  I’m not worried about AES from a 
> crypto/math-perspective, what worries me is that those arguing for 
> Camellia-removal seem to ignore the practical aspect.  It’s *far* more likely 
> that there’ll be an engineering-break, than a math-break.  What happens if 
> someone finds a key-leakage issue with a hardware crypto-implementation, 
> allowing leaking keys between XEN-instances for example?
>

How exactly is CAMELLIA helping here? Such a key leak probably affects
multiple ciphers.

> There seems to be an implied “the math is solid, therefor AES the algoritm is 
> secure, therefore all uses of AES is secure”.  The first conclusion is solid, 
> but not the second.
> 

There's still no security proof for AES to the best of my knowledge,
some block-cipher modes come with proofs attached though.

> I find the timing of this a bit puzzling to be honest.  It’s only this very 
> year that we saw usage of RC4 to mitigate BEAST for example.  That is, the 
> math-solid algoritms got shifted out by some, in favour of math-broken, 
> because they figured the tradeoff was better.  (Lots could be said about if 
> that was a good call or not).
>

BEAST was in 2011. What we saw this year is IETF prohibiting use of RC4.
Same thing for SSLv3.


> It tends not to be the crypto math that gets broken, but usage, 
> implementations, etc.
> 

Not sure where using exotic ciphers helps here, these are code-branches
people look at far less. For example: BoringSSL removed all CAMELLIA
code (i.e. chromium, android etc. won't support it anymore, since
they've switched their entire codebade to BoringSSL a few weeks back).

Aaron

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