I myself would be concerned over a downgrade attack. 

Recall that this only impacts BRSKI in as much as the device needs to be
provisioned *during* the disaster.  While there may yet be some classes
of devices that require this, I'm going to hazard (cough) a guess that
most first responders will have trained with the equipment they have
*prior* to the disaster.  For the remaining equipment, if it is part of
critical infrastructure and requires a network, then the network needs
to be up.  The only question then is whether the MASA server needs to be
up.  It is perfectly possible to design a system where that is the case.

Eliot


On 11/2/16 5:05 PM, Max Pritikin (pritikin) wrote:
> My position is that during a large scale disaster it would be foolish of us 
> to think that security is somehow less important. 
>
> BRSKI supports nonceless tokens that can be distributed in advance. These 
> include the serial number of the device and the domain CA cert so it IS NOT a 
> "master key".
>       A “master key” is too similar to a “back door” for me to support it. 
>
> BRSKI client may support physical presence (buttons etc) that put them in 
> ‘trust on first use’ mode. 
>
> BRSKI addresses ‘time without clocks’ through the use of nonces and section 
> 3.1.5.
>
> I could be persuaded toward a more generic tofu model only if devices include 
> an integrated hardware assisted endpoint assessment (think TPM style 
> attestation w/ runtime measurements). That technology isn’t really available 
> yet.
>
> The approaches provided here work with some prior planning but are not 
> magical. 
>
> Do you have pixie dust to suggest? 
>
> - max
>
>> On Nov 1, 2016, at 8:53 PM, Brian E Carpenter <[email protected]> 
>> wrote:
>>
>> Something over on homenet prompted me to send the following. I do have the
>> same concern for BRSKI - what's the disaster recovery mechanism when all
>> vendor MASAs are unreachable but we must restart the network anyway?
>>
>>   Brian
>>
>> -------- Forwarded Message --------
>> Subject: Re: [homenet] write up of time without clocks
>> Date: Wed, 2 Nov 2016 08:38:04 +1300
>> From: Brian E Carpenter <[email protected]>
>> Organization: University of Auckland
>> To: [email protected]
>>
>> On 02/11/2016 03:52, Philip Homburg wrote:
>> ...
>>> Which brings me to the following: given that all code has security issues,
>>> maybe devices should check for updates and just shutdown if they can't
>>> verify that they are running the latest firmware?
>> That sounds absolutely dreadful for disaster recovery scenarios where
>> the Internet is badly broken (after a hurricane, earthquake, etc.)
>> and people need to restart essential systems (or they need to restart
>> themselves).
>>
>>> So the device should have the vendor's long term TLS certicate. With 
>>> possibly
>>> an option for the user to disable this kind of security if the device is
>>> not actually connected to the internet.
>> No, during disaster recovery the last thing you need is for ordinary people
>> to be faced with strange security alerts that they've never seen before.
>> (It's rather like advising people to go into the BIOS to change an option
>> while the fire alarm is ringing.)
>>
>> Things need to just work during disaster recovery.
>>
>>    Brian
>>
>> _______________________________________________
>> Anima mailing list
>> [email protected]
>> https://www.ietf.org/mailman/listinfo/anima
> _______________________________________________
> Anima mailing list
> [email protected]
> https://www.ietf.org/mailman/listinfo/anima

Attachment: signature.asc
Description: OpenPGP digital signature

_______________________________________________
Anima mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/anima

Reply via email to