[CESG] CCSDS 355.0-R-1, Space Data Link Security Protocol (Red Book, Issue 1) vs Proximity-1

[Shames, Peter M (313B)]

Gippo,

On checking with interested parties here it appears that there is no pressing need to address Prox 1 at this time.  Further, I do understand that it was considered and tackling it was set aside in the interests of dealing with the more pressing (and more tractable) issues first, TC, AOS, and TM.

At this point it would suffice for me to have a note in the spec to describe the rationale of why it was left out.

I presume that the rest of the issues will be addressed by the WG.

Regards, Peter



From: Gian Paolo Calzolari <Gian.Paolo.Calzolari at esa.int<mailto:Gian.Paolo.Calzolari at esa.int>>
Date: Wed, 6 Apr 2011 09:42:15 -0700
To: CCSDS Engineering Steering Group - CESG Exec <cesg at mailman.ccsds.org<mailto:cesg at mailman.ccsds.org>>
Subject: [CESG] CCSDS 355.0-R-1, Space Data Link Security Protocol (Red Book, Issue 1) vs Proximity-1


Dear All,
        as you know is these days CESG Poll CESG-P-2011-03-005 is ongoing for the Approval to release CCSDS 355.0-R-1, Space Data Link Security Protocol (Red Book, Issue 1) for CCSDS Agency review.
Peter has approved the poll (thanks!) with some remarks.
I think it is worth to address his first remark (i.e. Why is Porx-1 not addressed along with TM, TC & AOS?  Is there the assumption that if data is securely delivered to space that relaying it is then not a problem? ) for sake of clarity.

The shortest answer to the question is that Proximity-1 is not addressed on purpose as SDLS WG decision; i.e. SDLS protocol is meant to protect TC Direct From Earth (DFE) and TM Direct To Earth (DTE)  space links.

Here are some points providing the rationale:
- The prime threats we are aiming to protect from with this SDLS protocol are on earth, not in space and surely not in deep space. This is why SDLS WG did not consider compatibility with Proximity-1 a necessary feature of the SDLS protocol. The User RequirementsDocument (URD) which was the basis for SDLS development did not list Proximity-1 as target data link protocol for the above mentioned reason.
- The WG had originally gone into the SDLS protocol development with the intent of creating a “shim” to allow it to work with TM, TC, AOS, *and* Prox-1.  But the more they looked at Prox-1, the more they realized that it would require changes to Proximity-1 to allow SDLS to work (they consulted with Greg Kazz on this).  So, WG idea was to define the SDLS protocol for those CCSDS link layer protocols that would not require any changes and then influence the next rewrite of Proximity to allow SDLS to be seamlessly incorporated.
- I think also  that there would be a  big number of issues (for key management etc.) to be tackled and recommending CCSDS 355.0-R-1 for Proximity-1 would just be misleading.without a thorough analysis of multi hop (even if limited to one hop right now) encrypted environment.
- In conclusion, adding Proximity-1 to SDLS would require serious rework (unless one is looking for mere formatting inclusion) and when its revised, the WG will include it in SDLS.

I hope this is clarifying the issue.

Best regards

Gian Paolo

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ccsds.org/pipermail/cesg/attachments/20110406/037dea26/attachment.html