From 23d97d691266e0447809584292379581cedfbc3d Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Tue, 19 Dec 2023 18:34:22 +0100
Subject: [PATCH] Incorporate diagram of OPS-signed message

---
 book/assets/drawio/ops-signed-message.drawio | 74 ++++++++++++++++++++
 book/assets/drawio/ops-signed-message.svg    |  3 +
 book/source/signing_data.md                  |  7 ++
 3 files changed, 84 insertions(+)
 create mode 100644 book/assets/drawio/ops-signed-message.drawio
 create mode 100644 book/assets/drawio/ops-signed-message.svg

diff --git a/book/assets/drawio/ops-signed-message.drawio b/book/assets/drawio/ops-signed-message.drawio
new file mode 100644
index 0000000..bedff83
--- /dev/null
+++ b/book/assets/drawio/ops-signed-message.drawio
@@ -0,0 +1,74 @@
+<mxfile host="app.diagrams.net" modified="2023-12-19T17:29:27.627Z" agent="Mozilla/5.0 (X11; Linux x86_64; rv:120.0) Gecko/20100101 Firefox/120.0" etag="RchAfgHZxGEJWryXLgsm" version="22.1.11" type="device">
+  <diagram name="Seite-1" id="06IJX984rhBGnz6KE12L">
+    <mxGraphModel dx="1646" dy="434" grid="1" gridSize="10" guides="1" tooltips="1" connect="1" arrows="1" fold="1" page="1" pageScale="1" pageWidth="827" pageHeight="1169" math="0" shadow="0">
+      <root>
+        <mxCell id="0" />
+        <mxCell id="1" parent="0" />
+        <mxCell id="9NkdM7txntXo-xmCDq8w-4" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=0;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;" edge="1" parent="1" source="9NkdM7txntXo-xmCDq8w-1" target="9NkdM7txntXo-xmCDq8w-3">
+          <mxGeometry relative="1" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-12" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;exitDx=0;exitDy=0;entryX=0;entryY=0.5;entryDx=0;entryDy=0;" edge="1" parent="1" source="9NkdM7txntXo-xmCDq8w-1" target="9NkdM7txntXo-xmCDq8w-14">
+          <mxGeometry relative="1" as="geometry">
+            <mxPoint x="480" y="310" as="targetPoint" />
+          </mxGeometry>
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-1" value="&lt;div&gt;One-Pass-Signature&lt;/div&gt;&lt;div&gt;Hash: SHA512&lt;/div&gt;&lt;div&gt;Fingerprint: 0xB0B0&lt;br&gt;&lt;/div&gt;" style="rounded=0;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+          <mxGeometry x="50" y="160" width="120" height="60" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-2" value="&lt;div&gt;Literal Data&lt;/div&gt;&lt;div&gt;&quot;Hello World!&quot;&lt;br&gt;&lt;/div&gt;" style="rounded=0;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+          <mxGeometry x="170" y="160" width="250" height="60" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-17" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;startArrow=classic;startFill=1;" edge="1" parent="1" source="9NkdM7txntXo-xmCDq8w-3" target="9NkdM7txntXo-xmCDq8w-14">
+          <mxGeometry relative="1" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-3" value="&lt;div&gt;Signature&lt;/div&gt;&lt;div&gt;Hash: SHA512&lt;br&gt;&lt;/div&gt;&lt;div&gt;Issuer: B0B0&lt;br&gt;&lt;/div&gt;" style="rounded=0;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+          <mxGeometry x="420" y="160" width="160" height="60" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-8" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=0;exitDx=0;exitDy=0;entryX=0.5;entryY=0;entryDx=0;entryDy=0;" edge="1" parent="1" source="9NkdM7txntXo-xmCDq8w-6" target="9NkdM7txntXo-xmCDq8w-7">
+          <mxGeometry relative="1" as="geometry">
+            <Array as="points">
+              <mxPoint x="-10" y="120" />
+              <mxPoint x="660" y="120" />
+            </Array>
+          </mxGeometry>
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-13" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;exitDx=0;exitDy=0;entryX=0;entryY=0.5;entryDx=0;entryDy=0;" edge="1" parent="1" source="9NkdM7txntXo-xmCDq8w-6" target="9NkdM7txntXo-xmCDq8w-16">
+          <mxGeometry relative="1" as="geometry">
+            <mxPoint x="640" y="420" as="targetPoint" />
+          </mxGeometry>
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-6" value="&lt;div&gt;One-Pass-Signature&lt;/div&gt;&lt;div&gt;Hash: SHA384&lt;/div&gt;&lt;div&gt;Fingerprint: 0xB0B1&lt;br&gt;&lt;/div&gt;" style="rounded=0;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+          <mxGeometry x="-70" y="160" width="120" height="60" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-18" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;exitDx=0;exitDy=0;startArrow=classic;startFill=1;" edge="1" parent="1" source="9NkdM7txntXo-xmCDq8w-7" target="9NkdM7txntXo-xmCDq8w-16">
+          <mxGeometry relative="1" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-7" value="&lt;div&gt;Signature&lt;/div&gt;&lt;div&gt;Hash: SHA512&lt;br&gt;&lt;/div&gt;&lt;div&gt;Issuer: B0B1&lt;br&gt;&lt;/div&gt;" style="rounded=0;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+          <mxGeometry x="580" y="160" width="160" height="60" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-19" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.1;exitY=0.5;exitDx=0;exitDy=0;exitPerimeter=0;endArrow=oval;endFill=1;" edge="1" parent="1" source="9NkdM7txntXo-xmCDq8w-9">
+          <mxGeometry relative="1" as="geometry">
+            <mxPoint x="310" y="280" as="targetPoint" />
+          </mxGeometry>
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-9" value="" style="shape=curlyBracket;whiteSpace=wrap;html=1;rounded=1;labelPosition=left;verticalLabelPosition=middle;align=right;verticalAlign=middle;rotation=-90;" vertex="1" parent="1">
+          <mxGeometry x="300" y="140" width="20" height="220" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-20" style="edgeStyle=orthogonalEdgeStyle;rounded=0;orthogonalLoop=1;jettySize=auto;html=1;exitX=0.5;exitY=1;exitDx=0;exitDy=0;endArrow=oval;endFill=1;" edge="1" parent="1" source="9NkdM7txntXo-xmCDq8w-10">
+          <mxGeometry relative="1" as="geometry">
+            <mxPoint x="310" y="310" as="targetPoint" />
+          </mxGeometry>
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-10" value="&quot;Hello World!&quot; is hashed" style="text;html=1;strokeColor=none;fillColor=none;align=center;verticalAlign=middle;whiteSpace=wrap;rounded=0;" vertex="1" parent="1">
+          <mxGeometry x="237.5" y="220" width="145" height="30" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-14" value="SHA512 Hash" style="rounded=1;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+          <mxGeometry x="440" y="260" width="120" height="40" as="geometry" />
+        </mxCell>
+        <mxCell id="9NkdM7txntXo-xmCDq8w-16" value="SHA384 Hash" style="rounded=1;whiteSpace=wrap;html=1;" vertex="1" parent="1">
+          <mxGeometry x="600" y="290" width="120" height="40" as="geometry" />
+        </mxCell>
+      </root>
+    </mxGraphModel>
+  </diagram>
+</mxfile>
diff --git a/book/assets/drawio/ops-signed-message.svg b/book/assets/drawio/ops-signed-message.svg
new file mode 100644
index 0000000..1079fa3
--- /dev/null
+++ b/book/assets/drawio/ops-signed-message.svg
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="811px" height="218px" viewBox="-0.5 -0.5 811 218"><defs/><g><path d="M 180 47 L 180 27 L 570 27 L 570 40.63" fill="none" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 570 45.88 L 566.5 38.88 L 570 40.63 L 573.5 38.88 Z" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="all"/><path d="M 180 107 L 180 167 L 503.63 167" fill="none" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 508.88 167 L 501.88 170.5 L 503.63 167 L 501.88 163.5 Z" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="all"/><rect x="120" y="47" width="120" height="60" fill="rgb(255, 255, 255)" stroke="rgb(0, 0, 0)" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 118px; height: 1px; padding-top: 77px; margin-left: 121px;"><div style="box-sizing: border-box; font-size: 0px; text-align: center;" data-drawio-colors="color: rgb(0, 0, 0); "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; pointer-events: all; white-space: normal; overflow-wrap: normal;"><div>One-Pass-Signature</div><div>Hash: SHA512</div><div>Fingerprint: 0xB0B0<br /></div></div></div></div></foreignObject><text x="180" y="81" fill="rgb(0, 0, 0)" font-family="Helvetica" font-size="12px" text-anchor="middle">One-Pass-Signature...</text></switch></g><rect x="240" y="47" width="250" height="60" fill="rgb(255, 255, 255)" stroke="rgb(0, 0, 0)" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 248px; height: 1px; padding-top: 77px; margin-left: 241px;"><div style="box-sizing: border-box; font-size: 0px; text-align: center;" data-drawio-colors="color: rgb(0, 0, 0); "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; pointer-events: all; white-space: normal; overflow-wrap: normal;"><div>Literal Data</div><div>"Hello World!"<br /></div></div></div></div></foreignObject><text x="365" y="81" fill="rgb(0, 0, 0)" font-family="Helvetica" font-size="12px" text-anchor="middle">Literal Data...</text></switch></g><path d="M 570 113.37 L 570 140.63" fill="none" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 570 108.12 L 573.5 115.12 L 570 113.37 L 566.5 115.12 Z" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="all"/><path d="M 570 145.88 L 566.5 138.88 L 570 140.63 L 573.5 138.88 Z" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="all"/><rect x="490" y="47" width="160" height="60" fill="rgb(255, 255, 255)" stroke="rgb(0, 0, 0)" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 158px; height: 1px; padding-top: 77px; margin-left: 491px;"><div style="box-sizing: border-box; font-size: 0px; text-align: center;" data-drawio-colors="color: rgb(0, 0, 0); "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; pointer-events: all; white-space: normal; overflow-wrap: normal;"><div>Signature</div><div>Hash: SHA512<br /></div><div>Issuer: B0B0<br /></div></div></div></div></foreignObject><text x="570" y="81" fill="rgb(0, 0, 0)" font-family="Helvetica" font-size="12px" text-anchor="middle">Signature...</text></switch></g><path d="M 60 47 L 60 7 L 730 7 L 730 40.63" fill="none" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 730 45.88 L 726.5 38.88 L 730 40.63 L 733.5 38.88 Z" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="all"/><path d="M 60 107 L 60 197 L 663.63 197" fill="none" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 668.88 197 L 661.88 200.5 L 663.63 197 L 661.88 193.5 Z" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="all"/><rect x="0" y="47" width="120" height="60" fill="rgb(255, 255, 255)" stroke="rgb(0, 0, 0)" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 118px; height: 1px; padding-top: 77px; margin-left: 1px;"><div style="box-sizing: border-box; font-size: 0px; text-align: center;" data-drawio-colors="color: rgb(0, 0, 0); "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; pointer-events: all; white-space: normal; overflow-wrap: normal;"><div>One-Pass-Signature</div><div>Hash: SHA384</div><div>Fingerprint: 0xB0B1<br /></div></div></div></div></foreignObject><text x="60" y="81" fill="rgb(0, 0, 0)" font-family="Helvetica" font-size="12px" text-anchor="middle">One-Pass-Signature...</text></switch></g><path d="M 730 113.37 L 730 170.63" fill="none" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 730 108.12 L 733.5 115.12 L 730 113.37 L 726.5 115.12 Z" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="all"/><path d="M 730 175.88 L 726.5 168.88 L 730 170.63 L 733.5 168.88 Z" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="all"/><rect x="650" y="47" width="160" height="60" fill="rgb(255, 255, 255)" stroke="rgb(0, 0, 0)" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 158px; height: 1px; padding-top: 77px; margin-left: 651px;"><div style="box-sizing: border-box; font-size: 0px; text-align: center;" data-drawio-colors="color: rgb(0, 0, 0); "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; pointer-events: all; white-space: normal; overflow-wrap: normal;"><div>Signature</div><div>Hash: SHA512<br /></div><div>Issuer: B0B1<br /></div></div></div></div></foreignObject><text x="730" y="81" fill="rgb(0, 0, 0)" font-family="Helvetica" font-size="12px" text-anchor="middle">Signature...</text></switch></g><path d="M 380 145 L 380 164" fill="none" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="stroke"/><ellipse cx="380" cy="167" rx="3" ry="3" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" pointer-events="all"/><path d="M 390 27 L 385 27 Q 380 27 380 37 L 380 127 Q 380 137 375 137 L 372.5 137 Q 370 137 375 137 L 377.5 137 Q 380 137 380 147 L 380 237 Q 380 247 385 247 L 390 247" fill="none" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" transform="rotate(-90,380,137)" pointer-events="all"/><path d="M 380 137 L 380 167 L 380 194" fill="none" stroke="rgb(0, 0, 0)" stroke-miterlimit="10" pointer-events="stroke"/><ellipse cx="380" cy="197" rx="3" ry="3" fill="rgb(0, 0, 0)" stroke="rgb(0, 0, 0)" pointer-events="all"/><rect x="307.5" y="107" width="145" height="30" fill="none" stroke="none" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 143px; height: 1px; padding-top: 122px; margin-left: 309px;"><div style="box-sizing: border-box; font-size: 0px; text-align: center;" data-drawio-colors="color: rgb(0, 0, 0); "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; pointer-events: all; white-space: normal; overflow-wrap: normal;">"Hello World!" is hashed</div></div></div></foreignObject><text x="380" y="126" fill="rgb(0, 0, 0)" font-family="Helvetica" font-size="12px" text-anchor="middle">"Hello World!" is hashed</text></switch></g><rect x="510" y="147" width="120" height="40" rx="6" ry="6" fill="rgb(255, 255, 255)" stroke="rgb(0, 0, 0)" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 118px; height: 1px; padding-top: 167px; margin-left: 511px;"><div style="box-sizing: border-box; font-size: 0px; text-align: center;" data-drawio-colors="color: rgb(0, 0, 0); "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; pointer-events: all; white-space: normal; overflow-wrap: normal;">SHA512 Hash</div></div></div></foreignObject><text x="570" y="171" fill="rgb(0, 0, 0)" font-family="Helvetica" font-size="12px" text-anchor="middle">SHA512 Hash</text></switch></g><rect x="670" y="177" width="120" height="40" rx="6" ry="6" fill="rgb(255, 255, 255)" stroke="rgb(0, 0, 0)" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 118px; height: 1px; padding-top: 197px; margin-left: 671px;"><div style="box-sizing: border-box; font-size: 0px; text-align: center;" data-drawio-colors="color: rgb(0, 0, 0); "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; pointer-events: all; white-space: normal; overflow-wrap: normal;">SHA384 Hash</div></div></div></foreignObject><text x="730" y="201" fill="rgb(0, 0, 0)" font-family="Helvetica" font-size="12px" text-anchor="middle">SHA384 Hash</text></switch></g></g><switch><g requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"/><a transform="translate(0,-5)" xlink:href="https://www.drawio.com/doc/faq/svg-export-text-problems" target="_blank"><text text-anchor="middle" font-size="10px" x="50%" y="100%">Text is not SVG - cannot display</text></a></switch></svg>
\ No newline at end of file
diff --git a/book/source/signing_data.md b/book/source/signing_data.md
index 24e2c75..43cf0ed 100644
--- a/book/source/signing_data.md
+++ b/book/source/signing_data.md
@@ -74,6 +74,13 @@ A {term}`one-pass signed<One-pass signed Message>` {term}`OpenPGP message` consi
 
 3. **{term}`Data signature packets<OpenPGP Signature Packet>`**: These contain the {term}`cryptographic signature` corresponding to the original data.
 
+```{figure} plain_svg/ops-signed-message.svg
+:name: fig-ops-signed-message
+:alt: Depicts the structure of a one-pass-signed message.
+
+The structure of a one-pass signed message.
+```
+
 ```{note}
 Despite its name, a {term}`one-pass signature packet` is not a type of {term}`signature packet<OpenPGP Signature Packet>`.