Subject: Re: Authentication or integrity?

From: Darren Moffat <[email-masked]>
Date: Wed, 4 Apr 2001 12:58:01 -0700 (PDT)

Everything you said about integrity makes sense.  However my view of
what SACRED intends to provide is to address the case where I need to
prove to some remote machine that I am who I claim to be so that it
can decided to give me the credentials that are mine.

Taking your locker analogy.  The locker has a simple key, but inside
it have stored my car keys, house keys, my bank cards and cheque book.
What I want from SACRED is a mechanism that allows me to authenticate
to the locker and then once doing that download the contents (the locker
itself should not interpret the contents).

When downloading the contents of the locker we should use a transport
mechanism that ensures the intgrity over space, I think the integrity
over time issue is outside the scope of what SACRED can provide since
to SACRED the contents of the creds are opaque.

Now since I've stored all my critical keys in the locker I don't want
to carry around a smartcard or token to authenticate to the locker I
want a simple secure thing to remember than can go across a channel
that doesn't require complex creds to setup (so no TLS or Secure Shell
or LIPKEY or anything like that can be used).

This is what I'm looking for, it may not be what SACRED WG ends up
providing.

--
Darren J Moffat

---

From: Eric Norman <[email-masked]>
Date: Wed, 4 Apr 2001 16:50:10 -0500 (CDT)

> can decided to give me the credentials that are mine.

And I'm claiming that proving my identity to a remote machine is
not necessary.  All I have to do is prove to myself the "are mine"
part.
 
> itself should not interpret the contents).

So what's the mechanism that prevents an eavesdropper from interpreting
the contents during the download?  I.e. the confidentiality part.

Now it looks like things would be more secure if you had to unlock
the locker and also unlock its contents, but wouldn't that mean that you
have to remember (or carry around) two keys?
 
> to SACRED the contents of the creds are opaque.

Even though it's opaque, you still need to know that the opaque bit blob
is bit for bit identical to what is was then (over time).

Eric Norman

	"Congress shall make no law restricting the size of integers
	that may be multiplied together, or the number of times that
	an integer may be multiplied by itself, or the modulus by
	which an integer may be reduced".