Work was started on STIX 2.1 at the end of 2016, long before STIX 2.0 was released as a CS. This represents a significant amount of work, as Trey pointed out. There is much “Text Complete” work to show from
this period, for instance:
This work was done under the informal TC process that was used to produce STIX 2.0. I think it is highly disruptive to introduce a new process in the middle of creating a new CS.
Therefore, my suggestion is that we declare STIX 2.1 to be “done”, and start the process for it to be released as the 2.1 CS. No additions will be allowed, and incomplete work will be dropped from 2.1.
We can then start the development of STIX 2.2 using the new fully-defined process discussed at the F2F. This also obviates the need for version numbers other than 2.1, since the only reason for various CSDs
will be editorial in nature. STIX 2.0 was accepted as a CS in July of 2017. Given our experiences as editors, and the process itself, STIX 2.1 probably wouldn’t be available as a CS until early summer, which is almost a year later.
I know some will dismiss this suggestion out of hand because it doesn’t include their pet new feature. However, there is good work which could be released to the community sooner if we take this route.
Here are the notes from today’s call.
The call began by articulating and re-affirming goals for STIX 2.1:
STIX 2.1 will be a strong technical specification that contributes to improving the defensive posture of organizations and institutions that support our societies by:
Promoting interoperability along key features, such as internationalization, malware, CoA, etc.
Permitting rapid feature iteration, for instance by creating an extension process, so that we can adapt to the evolving threat landscape
Including necessary backward breaking changes
Enabling broad marketplace adoption
Minimizing backward breaking changes for new work, through meeting the TC-approved “definition of done”
We also identified, for the purposes of the call, some terms to use when describing the status of issues:
TODO – The TC generally believes the feature is valuable, but has not started work
In Progress – The TC is under active deliberation to define a feature
Text Complete – The TC agrees on the text for a feature, and is ready to begin validating it through software implementations
In Test – The TC is in the process of validating that the feature works in software
Done – The feature is complete
After some deliberation, the perspective on the call identified that the critical question facing the TC is:
How do we enable rapid implementation of features that are already text complete without committing ourselves to untested text?
This is the question that, if left unanswered, will stall development of the STIX/TAXII 2.1 specifications indefinitely. Call participants were able to brainstorm some proposals, along with the common objections
that have been raised. Most notably, I believe we need to find an answer to the critical question and move forward with specification development, even if the answer has known flaws. As a group, we must find a way to move forward.
The answers brainstormed on the call (and shortly after in slack), along with their known objections, are:
- Use version number on individual STIX objects, i.e., stix2.1-csd01
- This potentially introduces an explosion of version numbers, resulting in interoperability issues
- Use version numbers in the MIME type, i.e., application/stix+json; version=2.1-csd01
- Multiple objections have been raised in various conversations, including slack, email, and GitHub
- Do not make any special distinction for individual drafts
- Objections relate to non-interoperability across draft versions
- Create an extension mechanism and use that
- Objections largely center around wanting to make sure key capabilities are in STIX 2.1
- Create a new STIX 2.0 CSD-03 that includes the changes in spec necessary for extensions going forward. This CSD would then be used as the basis for all 2.1 objects to be added
using extensions in a 2.1CSD01
The CTI TC’s must deliberate and select an answer to the critical question, and must proceed in unison once an answer is selected. Please debate the value of the various solutions, and continue to propose
The past week has generated a lot of discussion and varying perspectives on how best to proceed with development of STIX/TAXII 2.1. While there is general agreement on the goals for STIX/TAXII 2.1, the implementation
of these goals has uncovered some vigorously debated tradeoffs that warrant further discussion.
On today’s working call we will:
- Articulate and re-affirm the goals for STIX/TAXII 2.1
- Clearly identify the tradeoffs identified through goal implementation and discuss them constructively
- Consider a proposed solution for moving forward
- Arrive at a concrete proposal that we can use for the duration of STIX/TAXII 2.1 development
Mark Davidson | Engineering
1225 S. Clark Street, Suite 1103
Arlington, VA 22202
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