RE: NEW Data type for certificate selection ?

[Anders Rundgren <anders.rundgren@xxxxxxxxxx>]

Peter, see in-line comment below.

On Tue, 29 Sep 1998, Peter Gutmann wrote:

>In that, the server application cannot define anything, at most could
>suggest a list of CAs (see below), otherwise it would be easy either
>to subvert the user's security choices or do a DoS attack. So, the
>server must not be allowed to "help" in a decisive way which user
>cert *will* be used -- as though it might seem useful at first:
 
>> In order to make this user friendly, we have to create a mechanism
>> where a server can help a client application to select one proper
>> certificate out of many. In the example there is just 3
>> certificates to choose among but what if there is 20 or 30?

>but such is not safe.

The authenticating server may surely *suggest* a list of possible certificates
that it may accept because it is always *you* (the user) that should manually
select the proper one.  In case you feel that a cert with SSN could create a disaster
if you accidentally gave it to a wrong server the solution would be to have a local
(user-defined) set of valid servers (i.e. their public keys).

To insert a new server would require a few more clicks.  I.e. similar to ActiveX
controls or signed Java Applets.  Such servers would typically be
governmental (who gave you the SSN) and a *few* other parties that
you hopefully trust like your bank or employer.   A similar scheme could be used
for defining a list of valid receivers of mail signed with a cert containing an SSN
(or other sensitive information). 

I will come back soon with a server-to-cert selection scheme.

Anders