Re: [cti] CTI TC Timestamps - Proposed: Adopt the ISO 8601 <start>/<end> construct.

["Jordan, Bret" <bret.jordan@bluecoat.com>]

I have thought a lot about this, since Pat first brought it up and I believe he has a solid case for this. I do think that this might be a bit weird in the UI treatments if every timestamp allows a range.  But that is an implementation issue. I have questions of how this differs from precision.  And if we do this, can we not just drop the extra precision field?  That could make processing so much easier.  

Before we accept this, I would love to see some normative text written and added to the pre-draft specs.  I would like to see some examples of how precision would effect this and the normative text that would surround it (or can we just drop the precision field).  

Can we also get a line or two of text that talks about what to do if your tool can only support one timestamp?  I am guessing you would take the first one? 

Thanks,

Bret

Bret Jordan CISSP

Director of Security Architecture and Standards | Office of the CTO

Blue Coat Systems

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On Feb 1, 2016, at 21:35, Patrick Maroney <Pmaroney@Specere.org> wrote:

We are reaching final consensus on our CTI TimeStamp deliberations. This is a proposal to add a simple ISO 8601 Standard extension to the CTI TC TimeStamp specification that enables _expression_ of both "Absolute Time" and "Time Range" .

Proposal: 

 (1) Adopt the ISO 8601 <start>/<end> construct.  

(2) All of the constraints we are placing on the CTI Timestamp format remain intact:*

"Absolute Time":   "2015-03-01T13:00:00Z"

"Time Range":       "2015-03-01T13:00:00Z/2016-05-11T15:30:00Z"

(3) Parsing of the ISO 8601 <start>/<end> construct should be straightforward  (i.e., using  standard date-time libraries that support ISO 8601, regex).

*Note : This proposal only argues for the narrow adoption of the "/" Separator and would not allow any of the other ISO 8601 "Time Range "shortcuts" (e.g., "2014-2015", "2015-11-13/15", "2015-02-15/03-14").

There is significant benefit for use cases where there is a very real need to express events, actions, observables, COAs, etc. in time ranges.  For example- statutory incident/intrusion reporting deadline requirements (measured increasingly for many in hours/days) guarantee a need express and revise events in time ranges while investigations gather evidence and more accurately establish the sequence of events and timelines.  There are also many relationships that are more effectively expressed in time ranges, vs. fixed points in time.

Hopefully you see the value in adding this ISO 8601 capability to "our thing".

Patrick Maroney
President
Integrated Networking Technologies, Inc.
Desk: (856)983-0001
Cell: (609)841-5104
Email: pmaroney@specere.org

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