[Cryptography] How to build trust in crypto (was:recommending ChaCha20 instead of RC4)

Guido Witmond guido at witmond.nl
Tue Mar 18 15:44:36 EDT 2014

On 03/18/14 18:26, Ralf Senderek wrote:

> Not at all, if I wished to have a secure channel to Bruce Schneier 
> and I use key the key from his web site, I'd want that the one who is
> reading my encrypted messages is exactly the one that creates all the
> stuff that I get on the 15th day of the month. And I'd want that only
> this one person can decrypt and that this is done in a secure 
> environment which does not expose my messages to others. Short of 
> that I wouldn't call this a trusted communication, because the
> reason I'd start the contact is my belief that - given all the
> context I know about Bruce - this endpoint decryptor will actually
> respond to the content of my message in a way I can predict to be
> what I want it to be.

Hi Ralf,

> And (please) let me call this trust.

I'm not going to disappoint you :-) What you describe is called: Trust.

http://www.merriam-webster.com/dictionary/trust: "belief that someone or
something is reliable, good, honest, effective, etc"

Bruce doesn't offer any mechanisms so people can validate that the key
posted on his site is most likely his key. The GPG-key bears no
signatures from fellow sercurity researches. The website bears a Domain
Validated TLS-certificate. There are no DNSSEC/DANE records to specify
the CA he chose for that certificate.

Bruce also did not sign his reply to an email I had send. I read his
crypto-grams on the web, but I guess these are sent unsigned in the
mail. So trust is all that's left. The question is: How much?

Had Bruce used any of these methods above, the level of trust that the
key on the website actually belongs to him increases with use. Signing
each Crypto-gram issue with the key really does wonders.

That's what I'm trying to achieve with Eccentric. Distribute keys along
messages, so one can gain trust in the author. Private messages sent can
only be read by the owner of the private key. Whether they are called
Bruce, or 'Captain Kitten'.

One should not have to trust the key, One should verify it. Preferably
automatic by an agent on one's own computer.

Regards, Guido.

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