Re: [cti-cybox] Re: [cti-stix] Re: [cti-cybox] Revoke Cybox Observable

["Kirillov, Ivan A." <ikirillov@mitre.org>]

Thanks for the context, Sarah - very helpful.

To me, this comes down to being a language versus process question - that is, is Observable revocation something that should be addressed as part of the CybOX language, or should it be considered more as part of the processes in which CybOX is used? I’m leaning towards the latter, for the reason that the notion of revocation around Observables is something that doesn’t seem to fit as part of the data model around them. This is because, at their core, Observables represent some cyber “fact”, and what it does it mean to revoke a “fact”? At least with Indicators, you can argue that the Indicator may no longer be valid, or that its pattern is incorrect. With Observables, I think the semantics of revocation are not as clear and may not really make sense. 

At least in your case, it seems like we may need to consider defining some sort of garbage collection process, where Observables (and any other id-able CybOX/STIX entities) that were referenced and/or embedded in another entity and then no longer referenced be pruned from the datastore.

Regards,
Ivan



On 11/10/15, 12:31 PM, "cti-cybox@lists.oasis-open.org on behalf of Sarah Kelley" <cti-cybox@lists.oasis-open.org on behalf of Sarah.Kelley@cisecurity.org> wrote:

>Just to give a little context around this question, this came up in a
>conversation between Ali (well, several Soltra people) and myself today.
>
>In our instance of Soltra Edge, we have (on many occasions) had to ‘edit’
>an observable. Currently this involves editing the indicator, deleting the
>link to the current Cybox observable, and creating a new observable. This
>leaves lots of orphaned observables in our database that we really need to
>have the ability to purge. The understanding we have is that currently
>Cybox doesn’t support any sort of revoke/purge like Stix does.
>
>
>
>Sarah Kelley
>Senior CERT Analyst
>Center for Internet Security (CIS)
>Integrated Intelligence Center (IIC)
>Multi-State Information Sharing and Analysis Center (MS-ISAC)
>1-866-787-4722 (7×24 SOC)
>Email: cert@cisecurity.org
>www.cisecurity.org
>Follow us @CISecurity
>
>
>
>
>
>
>On 11/10/15, 11:06 AM, "cti-stix@lists.oasis-open.org on behalf of
>Kirillov, Ivan A." <cti-stix@lists.oasis-open.org on behalf of
>ikirillov@mitre.org> wrote:
>
>>Great question Ali; unfortunately I don’t have much insight into this
>>topic. Moving this to the STIX list - I think revocation is more specific
>>to STIX (though it clearly touches upon CybOX as well).
>>
>>Regards,
>>Ivan
>>
>>
>>
>>
>>On 11/10/15, 11:00 AM, "cti-cybox@lists.oasis-open.org on behalf of
>>Jerome Athias" <cti-cybox@lists.oasis-open.org on behalf of
>>athiasjerome@gmail.com> wrote:
>>
>>>Potential review of this
>>>https://stixproject.github.io/data-model/1.2/indicator/ValidTimeType/
>>>Suggestions welcome
>>>
>>>2015-11-10 18:48 GMT+03:00 Ali Khan <akhan@soltra.com>:
>>>> What is the cybox committees discussion so far for future versions to
>>>> support ability to revoke and remove completely a cybox observable
>>>>that was
>>>> created and then shared but now there is a need to remove it.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Thank You
>>>>
>>>>
>>>>
>>>> Ali Khan
>>>> Lead Analyst
>>>>
>>>> SOLTRA | An FS-ISAC & DTCC Company
>>>>
>>>> Tampa, fl 33647
>>>>
>>>> 813.470.2197 | akhan@soltra.com
>>>>
>>>>
>>>>
>>>>
>>>
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>>...
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