Re: Summary, was Re: Every time ..., was Re: General formula

[Tony Bartoletti <azb@xxxxxxxx>]

At 09:53 AM 6/4/99 -0700, Ed Gerck wrote:

[snip]

>Thus, slightly paraphrasing Andrew's following text, I may say:

[snip]

>The user does not need to make any assumption about attribute
>dependency besides the trivial case of not using fully redundant
>(whatever this may mean in the operational context) attributes; such
>as repeatingly using the same attribute lifetime in the equation if the
>attribute happens to repeated verbatim in the certificate -- since the
>attribute is essentially "one" if simply repeated."
>
>Hope it is clearer.
>
>Cheers,
>
>Ed Gerck

But is this "trivial case" always obvious?  This issue is rarely one
where we disagree axiomatically with statements like "Under these
premises, this formula holds true".  Rather, the disagreements arise
in assuming particular case data satisfy the formula's premises.

And "verbatum repetition" need not characterize "perfect redundancy".
My silly example:

We certify that person X is named "fred", person Y is named "john".

Fred's cert has one attribute:

1   Person's name = fred

John's cert has 5 attributes:

1   Person's name = fred
2   First letter of person's name  = j  (or first letter of attribute 1)
3   second letter of person's name = o
4   Third letter of person's name  = h
5   Fourth letter of person's name = n

I would love to see example lifetimes assigned to these attributes,
and how the formula might be applied.  Should the second certificate
have a shorter lifetime?  Can we "hide" redundancy even further?

Yes, almost anyone can see the strict dependency of attribute 1 with
attributes 2 .. 5 in the second cert.  But it seems intuitive that
in cases where attributes only "tend toward" perfect dependency, the
formula must yield a value that "tends toward" the value of any single
attribute.

I wish I could construct an example for (say) 100 "almost dependent"
attributes, each with expected lifetime t.  As "almost dependent" tends
toward perfection, intuition says that the collection must have an
expected lifetime that approaches t. I fail to see how the formula
can behave so.

Comments?

___tony___





Tony Bartoletti                                             LL
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