Re: [perpass] Tiny stacks

[Phillip Hallam-Baker <[e-mail]>]

On Mon, Dec 9, 2013 at 3:04 PM, Richard Barnes <[e-mail]> wrote:

> On Mon, Dec 9, 2013 at 2:47 PM, Brian E Carpenter <
> [e-mail]> wrote:
>
>> On 09/12/2013 11:04, Stewart Bryant (stbryant) wrote:
>> (on a different list and under a differeny Subject header)
>> ...
>>
>> > Remembering of course that some platforms which wish
>> > to use the Internet simply do not have the capability for
>> > other than a very tiny very basic stack.
>> >
>> > I always use the PIC and the Arduino to remind myself what the
>> > lower end of the franchise looks like.
>>
>> It seems to me that perpass should think a little bit about
>> privacy and anti-surveillance issues for devices with tiny
>> stacks, and see if that calls for any specific IETF work items.
>>
>
> This is not unexplored territory.
> <http://tools.ietf.org/html/draft-ietf-core-coap-18>
> <http://tools.ietf.org/html/draft-aks-crypto-sensors-02>
> <http://tools.ietf.org/wg/dice/>
>

COAP on a PIC? Really?

Or are you talking about the 32bit one rather than the 8 bit one that is
made in roughly double quantities year on year. The 8 bit one comes with
4Kbytes. I don't think you can get a TCP/IP stack in there.

But you do quite often need to get some form of end to end security from a
control system to an end point with a 6502 or Z80 class embedded device
that is connected over an I2C or RS485 link.

Right now that territory is occupied by MODBUS which is a protocol that
hasn't changed since I used it thirty years ago before I went to college.
It has no authentication or encryption and only limited error checking
capabilities. We run nuclear power plants off MODBUS but the folk who do
firework displays use MIDI because it has better error checking (oh I kid
you not).


We don't necessarily need to do IP end to end. I have never been a fan of
that particular dogma. IP is a rotten match for RS485 at 9600baud. But
being able to authenticate control messages and sensor readings end to end
is badly needed.


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