Crypto and UI issues

[Ben Laurie]

James A. Donald wrote:
>     --
> From:           	Ben Laurie <ben at algroup.co.uk>
> 
>>if the key changes in OpenSSH you can't connect until 
>>you take positive action by deleting the old key from 
>>the known_hosts file. This is totally different to 
>>accepting a new key.
>>
>>I will agree that something better than just showing 
>>you the key would be cool. Like maybe it could be 
>>signed by something so you can verify it that way. Oh, 
>>wait. That's PKI, and we all know PKI is broken.
> 
> 
> But in what it is it broken?

I was being sarcastic. I don't believe PKI is inherently broken, unlike
some. It does have limited uses, though.

> Let us imagine that SSH had certified keys.  Well, 
> certifying a key is bound to be complicated, and things 
> are bound to go wrong, and the name that you bind it to 
> is bound to be somewhat shifty.

I don't see why that would happen all that much, and if it did then just
certify with multiple hostnames.

>  You might bind the key 
> to ben.com, but then your host is ssh.ben.com.  So 
> pretty soon users are frequently seeing error dialogs - 
> and so, pretty soon, are always clicking through them.

Don't really buy this for what is, mostly, a protocol used by experts.

> What is a true name is a deep and difficult question, 
> and one that people have little patience for when trying 
> to log in.  We are overloaded with names, with the 
> result that true names are of limited value in 
> ascertaining true relationships. 

True names of hosts is not a deep problem. Indeed, it is even possible
to discover rigorously (if painfully in extereme cases).

Cheers,

Ben.


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