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<p class="MsoNormal"><span style="font-size:11.0pt">Hi everyone, <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Thanks for your support and interest. Regarding logistics of doing a joint session with SEC and to Tomaso’s point:
<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#212121">Concerning the meetings schedule, the slot for the joint SEC/DTN meeting is already scheduled on Thursday the 7</span><sup><span style="font-family:"Calibri",sans-serif;color:#212121">th</span></sup><span class="apple-converted-space"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#212121"> </span></span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#212121">in
the afternoon, starting from 1330. My suggestion would be then to iterate with SEC folks to come up with a list of items and related time allocation for the joint meeting. I’m cc’ing Howie and Marcus to converge.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">I think a common session with the Security WG would be a great idea. Howie & Marcus, I think a 45-1hr time slot would be ample enough time for us to get our idea out and discuss in the groups. Here’s a rough
outline of topics we would like to discuss: <o:p></o:p></span></p>
<ol style="margin-top:0in" start="1" type="1">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1"><span style="font-size:11.0pt">Overview
<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1"><span style="font-size:11.0pt">Security guarantees of BPSec under the Default Security Context and concerns<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1"><span style="font-size:11.0pt">Related works/ideas
<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1"><span style="font-size:11.0pt">Improvements to BPSec with ‘Read Receipts’<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1"><span style="font-size:11.0pt">Possible ways to incorporate improvements<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1"><span style="font-size:11.0pt">Discussion<o:p></o:p></span></li></ol>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Felix, in response to your point:<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;color:#212121">Regarding message loss detection, is there some overlap with the sequence numbering we are seeking to introduce in the Compressed Bundle Reporting / Custody transfer
Orange Book (<a href="https://docs.google.com/document/d/1YPTwJ7_3az5WliWspg0F0M2FsoPoCoVS/edit" title="Original URL:
https://docs.google.com/document/d/1YPTwJ7_3az5WliWspg0F0M2FsoPoCoVS/edit
Click to follow link."><span style="color:#0078D7">https://docs.google.com/document/d/1YPTwJ7_3az5WliWspg0F0M2FsoPoCoVS/edit</span></a>)?<span class="apple-converted-space"> </span><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in;caret-color: rgb(33, 33, 33);font-variant-caps: normal;orphans: auto;text-align:start;widows: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-size:11.0pt;color:#212121">In its simplest form, the CREB just contains a bundle sequence number (‘scoped’ by the source node) with sequences according to the bundle’s destination endpoint IDs. This CREB actually does not request any reporting
(maybe we should work on terminology) but allows the destination node to detect gaps in sequences of bundles (and do re-ordering if required).<span class="apple-converted-space"> </span><o:p></o:p></span></p>
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<span style="font-size:11.0pt;color:#212121"> <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Our work looks at loss detection from a cryptographic perspective but I think we can incorporate the sequence number described in what we MAC over as part of our ‘read-receipt’ concept that we introduce in
the paper to permit only honest changes by intermediate nodes to a bundle in flight from a sender to the security destination. Happy to talk more about how we could integrate these two concepts together more at the meeting.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Very Respectfully,
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Xisen Tian<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">LT USN
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">PhD Student<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Applied Cryptography<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Naval Postgraduate School<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span lang="EN-GB" style="font-size:12.0pt;color:black">From:
</span></b><span lang="EN-GB" style="font-size:12.0pt;color:black">Felix Flentge <Felix.Flentge@esa.int><br>
<b>Date: </b>Monday, September 23, 2024 at 11:15 PM<br>
<b>To: </b>Tian, Xisen (LT) <xisen.tian1@nps.edu>, sis-dtn@mailman.ccsds.org <sis-dtn@mailman.ccsds.org><br>
<b>Cc: </b>Hale, Britta (CIV) <britta.hale@nps.edu>, Bhagya Wimalasiri <b.m.wimalasiri@sheffield.ac.uk>, Benjamin Dowling <dowling.bj@gmail.com><br>
<b>Subject: </b>RE: Spring Meeting Agenda Add: BPSec Analysis and Improvements<o:p></o:p></span></p>
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<p class="MsoNormal" style="line-height:12.0pt;background:#004679"><span lang="EN-GB" style="font-family:"Calibri",sans-serif;color:yellow">NPS WARNING: *external sender* verify before acting.<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-GB" style="font-size:12.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt"> <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">I think this is super interesting and we should try to have the presentation in the common session with the Security WG.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt"> <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">Regarding message loss detection, is there some overlap with the sequence numbering we are seeking to introduce in the Compressed Bundle Reporting / Custody transfer Orange Book (<a href="https://docs.google.com/document/d/1YPTwJ7_3az5WliWspg0F0M2FsoPoCoVS/edit">https://docs.google.com/document/d/1YPTwJ7_3az5WliWspg0F0M2FsoPoCoVS/edit</a>)?
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">In its simplest form, the CREB just contains a bundle sequence number (‘scoped’ by the source node) with sequences according to the bundle’s destination endpoint IDs. This CREB actually does not
request any reporting (maybe we should work on terminology) but allows the destination node to detect gaps in sequences of bundles (and do re-ordering if required).
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">Felix<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> SIS-DTN <sis-dtn-bounces@mailman.ccsds.org>
<b>On Behalf Of </b>Tian, Xisen (LT) via SIS-DTN<br>
<b>Sent:</b> Tuesday, September 24, 2024 3:23 AM<br>
<b>To:</b> sis-dtn@mailman.ccsds.org<br>
<b>Cc:</b> Hale, Britta (CIV) <britta.hale@nps.edu>; Bhagya Wimalasiri <b.m.wimalasiri@sheffield.ac.uk>; Benjamin Dowling <dowling.bj@gmail.com><br>
<b>Subject:</b> [Sis-dtn] Spring Meeting Agenda Add: BPSec Analysis and Improvements</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><span lang="EN-GB" style="font-size:11.0pt"> <o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt">Hello,
</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt"> </span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt"> </span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt">I’m Xisen Tian, I’m a PhD student being advised by Dr. Britta Hale and Scott Burleigh at the Naval Postgraduate School researching cryptographic analysis of DTN protocols. My co-authors
(cc’d) and I have completed a formal analysis of BPSec with recommendations for improvements which we are ready to present to the DTN WG at the upcoming fall meeting in London. We would like to request a 30-45 minute time slot in the agenda to do a presentation
of our work followed by discussion on how our improvements could be adopted (if at all). Our full paper is forthcoming: it has been submitted to a journal and we are currently going through the review/revision process. I’ve pasted our abstract below:</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt"> </span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt">ABSTRACT: Space networking has become an increasing area of development with the advent of commercial satellite networks such as those hosted by Starlink and Kuiper, and increased
satellite and space presence by governments around the world. Yet, historically such network designs have not been made public, leading to limited formal cryptographic analysis of the security offered by them. One of the few public protocols used in space
networking is the Bundle Protocol, which is secured by Bundle Protocol Security (BPSec), an Internet Engineering Task Force (IETF) standard. We undertake a first analysis of BPSec, building a model of the secure channel security goals stated in the IETF standard,
and note issues therein with message loss detection. We prove security of BPSec under a limited model and also provide a stronger construction, one that supports the Bundle Protocol’s functionality goals while also ensuring destination awareness of missing
messages components.</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt"> </span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt">Please let me know if you have questions, concerns, or feedback. Thank you.
</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt"> </span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Very Respectfully,
</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> </span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Xisen Tian</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">LT USN
</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">PhD Student</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Applied Cryptography</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Naval Postgraduate School</span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><span style="font-size:11.0pt"> </span><span lang="EN-GB" style="font-size:11.0pt"><o:p></o:p></span></p>
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prohibited. If you have received this e-mail in error, please notify the sender immediately. ESA applies appropriate organisational measures to protect personal data, in case of data privacy queries, please contact the ESA Data Protection Officer (dpo@esa.int).
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