[Discuss] Good and Bad Crypto

[Derek Martin]

On Tue, Apr 22, 2014 at 11:40:58AM +0000, Edward Ned Harvey (blu) wrote:
> > From: discuss-bounces+blu=nedharvey.com at blu.org [mailto:discuss-
> > bounces+blu=nedharvey.com at blu.org] On Behalf Of Tom Metro
> > 
> > Being open source [...]. It's
> > is merely a necessary precondition for determining that crypto is
> > trustworthy.
> 
> Sorry, but this statement is simply false.

Anything involving security or encryption is rarely simply anything.

> Tell me the difference between the AesManaged class library, when I
> run it under closed-source .NET, and when I run it under open-source
> mono?  There is literally no difference.  It's a standard,
> deterministic library with literally the exact same binary output
> given the same input.  Closed or open is irrelevant, because the
> behavior is standard, published, verifiable, deterministic.

Hogwash.  The difference is interested, qualified parties can't
inspect the implementation to see if, say, using a particular key
won't make the implementation upload logs of all your transactions to
a black hat site, or download kiddie porn to your hardrive, etc..
If you can't inspect it, you can't trust it.  Period.

> > Using a proprietary library that implements an open *standard* is way
> > better than one where the developer decided to roll his own crypto
> > algorithm.
> 
> Nobody rolls his own crypto algorithm.  And I mean nobody.
> 
> Everybody, and I mean everybody, uses a standard library implementation of an open standard.

This is also utter nonsense.  

http://books.google.com/books?id=GToEAAAAMBAJ&pg=RA1-PA117&lpg=RA1-PA117&dq=insecure+proprietary+encryption+algorithm&source=bl&ots=mu7p4S2lrF&sig=o-0RjkKNIiJW8zkc0koyxz9O3o0&hl=en&sa=X&ei=b4lWU6KuMo6-sQTRiIDYBg&ved=0CG4Q6AEwCQ#v=onepage&q=insecure%20proprietary%20encryption%20algorithm&f=false

It took me ~5s to prove that statement wrong.  

-- 
Derek D. Martin    http://www.pizzashack.org/   GPG Key ID: 0xDFBEAD02
-=-=-=-=-
This message is posted from an invalid address.  Replying to it will result in
undeliverable mail due to spam prevention.  Sorry for the inconvenience.