[Cryptography] Petnames & Zooko's triangle -- theory v. practice (was Email and IM are...)

[James A. Donald]

On 2013-08-28 7:33 PM, ianG wrote:
> On 28/08/13 02:44 AM, radix42 at gmail.com wrote:
>> Zooko's triangle, pet names...we have cracked the THEORY of secure 
>> naming, just not the big obstacle of key exchange.
>
>
> Perhaps in a sense of that, I can confirm that we may have an elegant 
> theory but practice still eludes us.  I'm working with a design that 
> was based on pure petnames & ZT, and it does not deliver as yet.
>
> One part of the problem is that there are too many things demanding 
> names, which leads to addressbook explosion.  I have many payment 
> vehicles, many instruments, and in a fuller system, many identities. 
> Each demanding at least one petname.
>
> And so do my many counterparties.  A second part of the problem is 
> that petnames are those I give myself to some thing, but in some 
> definitional sense, I never export my petnames (which is from which 
> they derive their security).  Meanwhile, the owner of another thing 
> also has a name for it which she prefers to communicate about, so it 
> transpires that there is a clash between her petname and my petname.  
> To resolve this I am exploring the use of nicknames, which are 
> owner-distributed names, in contrast to petnames which are private names.
>
> Which of course challenges the user even more as she now has two 
> namespaces of subtle distinction to manage.  Kerckhoffs rolls six 
> times in his grave.
>
> Then rises the notion of secured nicknames, as, if Alice can label her 
> favourite payment receptacle "Alice's shop" then so can Mallory.  Doh! 
> Introduction can resolve that in theory, but in practice we're right 
> back to the world of identity trickery and phishing.  So we need a way 
> to securely accept nicknames, deal with clashes, and then preserve 
> that security context for the time when someone wishes to pay the real 
> Alice.  Otherwise we're back to that pre-security world known as 
> secure browsing.
>
> Then, map the privacy question over the above mesh, and we're in a 
> traffic analyst's wetdream.  One minor advantage here is that, 
> presswise, we only need to do a little better than Bitcoin, which is 
> no high barrier ;)
>
> In sum, I think ZT has inspired us.  It asks wonderfully elegant 
> questions, and provides a model to think about the issues. Petnames 
> and related things like capabilities answer a portion of those 
> questions, but many remain.  Implementation challenges!
>

Because email addresses and urls are already for the most part non human 
memorable, we already have implementations of Zooko's triangle which 
seem to work fine for the ordinary end user.

The old petname tool, (which has now probably succumbed to bitrot) used 
the browser's bookmark list to store public key data, thus was an 
implementation of Zooko's triangle, that piggy backed on the browser's 
implementation of Zooko's triangle for non human memorable urls.  It 
worked fine for me.

My petnames are still on the browser bar, providing easy access to my 
bank and stuff, though no longer providing security.