Re: [PATCH v4 2/14] Add TSEM specific documentation.

Casey Schaufler
2025-01-17T18:40:55Z

On 1/16/2025 8:47 PM, Dr. Greg wrote:
> On Mon, Jan 13, 2025 at 08:29:47PM -0500, Paul Moore wrote:
>
...

>> Please define the CELL acronym here as I believe it is the first use of
>> "CELL" in this document.
> FWIW, CELL isn't an acronym, it is a metaphor.
>
> TSEM was conceptually inspired by and derived from the Turing Abstract
> Machine Model (TAMM), as applied to the problem of modeling the
> security state of an execution domain.
>
> As everyone reading this knows, a TAMM, in practice, consists of a
> head traversing an infinite paper tape divided into cells that direct
> the next state of the machine.
>
> In TSEM, the model consists of a Context Of Execution (COE) with
> security definining characteristics, traversing a finite set of
> measurement points of infinite length, with defining characteristics
> at each point.
>
> We refer to a measurement point and its characteristics as a CELL in
> deference to the inspiration for all of this.
>
> We will add this explanation to the documentation.

Communication within a community as culturally diverse as the Linux
kernel developers* requires that you do not assume that "everyone reading
this" knows much of anything beyond how to type "make". Let's face it,
there are kernel developers today who would look at the Turing test and
say "is that even a thing?" There are others who don't have an education
that includes mid-twentieth century technological history.

[* Yes, an awful lot of Linux kernel developers are western males. ]

...

> We believe there is a technical solution to this problem as well but
> our work on that front, at this point, is too technically immature to
> go into.

Didn't Pierre de Fermat say something like that about some theorem
or another?

...

... Sorry, all I have time for today.