[bc1cindy]

superseeded #38

adds 32 wallet visualization of the decay, shipped as light and dark external svg files that the book paints per theme

the sources run along the rows and the rounds along the columns, with the same coin struck in both graphs

follow up

besides that, there are the open title suggestions that @yuval-block asked for:

so to be a bit more precise i think the "collaborative transaction privacy" title is descriptive of the content, but it doesn't quite capture that in the context of this repo it defines the problem that we're trying to solve

and if we just emphasize problem definition for fungi, that sells short the applicability of this perspective to alternatives

so i think a good title would address both of these, whereas my current title and your proposed alternatives only focuses on the first function of this doc

suggestions:

• The deanonymization problem in collaborative transactions
• What collaborative transactions must not leak

any other?

[oakagent]

ACK 897ff1b (automated): reviewed 1 commit 897ff1b; no findings.

[oakagent]

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[yuval-block]

in the variant that eventually decided to go with the crossbar style connections also straddle the original input coins, which is a bit confusing, the n=16 diagram doesn't have this glitch

also using the colors that were used for alice and bob is perhaps confusing i think it would be clearer if the candidates were in the user's color but faded, struck off items displayayed as neutral and confirmed origin displayed in the user color

[bc1cindy]

in the variant that eventually decided to go with the crossbar style connections also straddle the original input coins, which is a bit confusing, the n=16 diagram doesn't have this glitch

also using the colors that were used for alice and bob is perhaps confusing i think it would be clearer if the candidates were in the user's color but faded, struck off items displayayed as neutral and confirmed origin displayed in the user color

• crossbars now sit in the gap between rounds instead of over the coins
• candidates are a faded version of alice's color, struck off coins are neutral gray, and the confirmed origin is alice's full color (bob's orange is gone)
• lines leading into struck off coins are gray too
• dropped the extra 8th column: the fragile graph only has 6 joins, so alice's output was left unconnected.

what about now? @yuval-block

[yuval-block]

yeah i think this is clearer, thank you

[oakagent]

ACK e647534 (automated): reviewed 1 commit e647534; no findings.

[github-actions]

range-diff for force push e647534178 → 43d4932e96 October 21, 2026 21:37 UTC: 1 modified

^{reproduce: git range-diff 6149b07..e647534 6149b07..43d4932}

1:  e647534178 ! 1:  43d4932e96 illustrate the decay regimes at 32 wallets

1: e647534178 ! 1: 43d4932e96 illustrate the decay regimes at 32 wallets

@@ collaborative_txn_privacy.md: For example, a chain analysis vendor with KYC info
  If the CoinJoin graph is *robustly connected*[^flow], then no small cut separates any output from the mass of its candidate origin coins. Stated differently, every output is connected to its candidate origins by multiple disjoint paths.
  
  This redundancy forestalls the cliff of exponential decay, where privacy becomes much more brittle, extending the duration of the linear decay regime by requiring the adversary to deanonymize a much larger proportion of users before divide-and-conquer tactics start coming into play.
-+<div class="chart-src f32" role="img" aria-label="Two CoinJoin graphs of thirty-two wallets under the same ten deanonymizations.">
++<div class="chart-src f32">
 +<picture>
 +  <source media="(prefers-color-scheme: dark)" srcset="src/figures/figure-32-dark.svg">
 +  <img src="src/figures/figure-32-light.svg" alt="Two CoinJoin graphs of thirty-two wallets under the same ten deanonymizations: mixing sheds one candidate per strike; merges through a single coin collapse to one.">
@@ contrib/figures.py (new)
 +import json
 +import re
 +import sys
++from html import escape
 +from html.parser import HTMLParser
 +from pathlib import Path
 +
@@ contrib/figures.py (new)
 +    def __init__(self, markup):
 +        super().__init__()
 +        self.images = {}
++        self.alt = ''
 +        self.feed(markup)
 +
 +    def handle_starttag(self, tag, attrs):
 +        attrs = dict(attrs)
 +        if tag == 'img':
 +            self.images['light'] = attrs.get('src', '')
++            self.alt = attrs.get('alt', '')
 +        elif tag == 'source' and attrs.get('media') == '(prefers-color-scheme: dark)':
 +            self.images['dark'] = attrs.get('srcset', '')
 +
 +
 +def embed(match, root):
-+    images = Picture(match.group()).images
++    picture = Picture(match.group())
++    images = picture.images
 +    # Only handle the paired, checked-in chart assets, not unrelated pictures.
 +    if set(images) != {'light', 'dark'} or not all(
 +        re.fullmatch(r'src/figures/figure-\d+-' + theme + r'\.svg', path)
@@ contrib/figures.py (new)
 +            svg,
 +            flags=re.S,
 +        )
++        # The svg replaces the img, so it has to carry the img's alt as its label.
++        if picture.alt:
++            svg = re.sub(
++                r'<svg\b[^>]*>',
++                lambda tag: re.sub(r'\s(?:role|aria-label)="[^"]*"', '', tag.group())[:-1]
++                + f' role="img" aria-label="{escape(picture.alt)}">',
++                svg,
++                count=1,
++            )
 +        # A blank line ends a CommonMark raw HTML block. Keep the SVG in
 +        # one block so its text and shapes are not parsed as Markdown.
 +        svg = '\n'.join(line for line in svg.splitlines() if line.strip())
@@ src/figures/figure-32-light.svg (new)
  \ No newline at end of file
 
  ## theme/diagrams.css ##
+@@
+    once per theme and swapped here; graphviz keeps whatever its .dot source
+    asks for, with only graphviz's own defaults lifted for the dark themes. */
+ .mdbook-graphviz-output,
+-.mermaid {
++.mermaid,
++.chart-src {
+     overflow-x: auto;
+     margin: 1rem 0;
+ }
+@@
+ /* Scale wide graphs down to the content column instead of clipping them;
+    the svg viewBox keeps them sharp at any size. */
+ .mdbook-graphviz-output svg,
+-.mermaid svg {
++.mermaid svg,
++.chart-src svg {
+     display: block;
+     max-width: 100%;
+     height: auto;
+@@
+    only just overflow still fit without scrolling. */
+ @media (max-width: 700px) {
+     .mdbook-graphviz-output,
+-    .mermaid {
++    .mermaid,
++    .chart-src {
+         margin-left: calc(-1 * var(--page-padding, 15px));
+         margin-right: calc(-1 * var(--page-padding, 15px));
+         padding: 0 var(--page-padding, 15px);
+     }
+ 
+     .mdbook-graphviz-output svg,
+-    .mermaid svg {
++    .mermaid svg,
++    .chart-src svg {
+         max-width: none;
+     }
+ }
 @@ theme/diagrams.css: html:is(.coal, .navy, .ayu) .mdbook-graphviz-output [fill="black"] {
  html:is(.coal, .navy, .ayu) .mdbook-graphviz-output text:not([fill]) {
      fill: #b7b7b7;
@@ theme/diagrams.css: html:is(.coal, .navy, .ayu) .mdbook-graphviz-output [fill="b
 +
 +/* The build embeds both palettes as inline SVG. GitHub keeps the source
 +   picture; book themes select a palette without fetching another image. */
-+.chart-src {
-+    margin: 1rem auto;
-+}
-+
-+.chart-src svg {
-+    display: block;
-+    max-width: 100%;
-+    height: auto;
-+}
-+
 +.chart-dark {
 +    display: none;
 +}

[github-actions]

range-diff for force push 43d4932e96 → ac4a500b6a October 22, 2026 01:41 UTC: 1 modified

^{reproduce: git range-diff 6149b07..43d4932 6149b07..ac4a500}

1:  43d4932e96 ! 1:  ac4a500b6a illustrate the decay regimes at 32 wallets

1: 43d4932e96 ! 1: ac4a500b6a illustrate the decay regimes at 32 wallets

@@ Commit message
 
     Ten strikes leave twenty-two candidates against one.
 
-    Keep light and dark SVGs as separate files, referenced through a picture
-    in the Markdown source so the figure renders on GitHub.
-
-    During the mdBook build only, embed both SVGs into the generated HTML.
-    Select the version matching the book theme and use the light version
-    for printing, avoiding extra image requests and CSS backgrounds.
+    Keep light and dark SVGs as separate files, marked with GitHub's
+    #gh-light-mode-only and #gh-dark-mode-only fragments. The book selects
+    the same files by theme, and prints the light one.
 
  ## book.toml ##
 @@ book.toml: after = ["links", "graphviz"]
@@ collaborative_txn_privacy.md: For example, a chain analysis vendor with KYC info
  
  This redundancy forestalls the cliff of exponential decay, where privacy becomes much more brittle, extending the duration of the linear decay regime by requiring the adversary to deanonymize a much larger proportion of users before divide-and-conquer tactics start coming into play.
 +<div class="chart-src f32">
-+<picture>
-+  <source media="(prefers-color-scheme: dark)" srcset="src/figures/figure-32-dark.svg">
-+  <img src="src/figures/figure-32-light.svg" alt="Two CoinJoin graphs of thirty-two wallets under the same ten deanonymizations: mixing sheds one candidate per strike; merges through a single coin collapse to one.">
-+</picture>
++<img src="src/figures/figure-32-light.svg#gh-light-mode-only" loading="lazy" alt="Two CoinJoin graphs of thirty-two wallets under the same ten deanonymizations: mixing sheds one candidate per strike; merges through a single coin collapse to one.">
++<img src="src/figures/figure-32-dark.svg#gh-dark-mode-only" loading="lazy" alt="Two CoinJoin graphs of thirty-two wallets under the same ten deanonymizations: mixing sheds one candidate per strike; merges through a single coin collapse to one.">
 +</div>
 +
 +*The same ten peers, deanonymized in the same order, in both graphs.*
@@ collaborative_txn_privacy.md: For example, a chain analysis vendor with KYC info
  ## contrib/figures.py (new) ##
 @@
 +#!/usr/bin/env python3
-+"""Embed chart pictures in the book; keep repository image paths on GitHub."""
++"""Point chart images at the book's copy; the source keeps repository paths for GitHub."""
 +import json
-+import re
 +import sys
-+from html import escape
-+from html.parser import HTMLParser
-+from pathlib import Path
-+
-+PICTURE = re.compile(r'<picture>\s*<source\b[^>]*>\s*<img\b[^>]*>\s*</picture>', re.S)
-+
-+
-+class Picture(HTMLParser):
-+    def __init__(self, markup):
-+        super().__init__()
-+        self.images = {}
-+        self.alt = ''
-+        self.feed(markup)
-+
-+    def handle_starttag(self, tag, attrs):
-+        attrs = dict(attrs)
-+        if tag == 'img':
-+            self.images['light'] = attrs.get('src', '')
-+            self.alt = attrs.get('alt', '')
-+        elif tag == 'source' and attrs.get('media') == '(prefers-color-scheme: dark)':
-+            self.images['dark'] = attrs.get('srcset', '')
-+
-+
-+def embed(match, root):
-+    picture = Picture(match.group())
-+    images = picture.images
-+    # Only handle the paired, checked-in chart assets, not unrelated pictures.
-+    if set(images) != {'light', 'dark'} or not all(
-+        re.fullmatch(r'src/figures/figure-\d+-' + theme + r'\.svg', path)
-+        for theme, path in images.items()
-+    ):
-+        return match.group()
-+    fragments = []
-+    for theme in ('light', 'dark'):
-+        svg = (root / images[theme]).read_text()
-+        scope = 'chart-' + Path(images[theme]).stem
-+        # Inline SVG styles belong to the whole document. Scope the asset's
-+        # class selectors so its palette cannot affect other figures/diagrams.
-+        svg = re.sub(
-+            r'<style>(.*?)</style>',
-+            lambda style: '<style>' + re.sub(
-+                r'(\.[a-zA-Z_][\w-]*)\s*\{',
-+                lambda selector: '.' + scope + ' ' + selector.group(1) + '{',
-+                style.group(1),
-+            ) + '</style>',
-+            svg,
-+            flags=re.S,
-+        )
-+        # The svg replaces the img, so it has to carry the img's alt as its label.
-+        if picture.alt:
-+            svg = re.sub(
-+                r'<svg\b[^>]*>',
-+                lambda tag: re.sub(r'\s(?:role|aria-label)="[^"]*"', '', tag.group())[:-1]
-+                + f' role="img" aria-label="{escape(picture.alt)}">',
-+                svg,
-+                count=1,
-+            )
-+        # A blank line ends a CommonMark raw HTML block. Keep the SVG in
-+        # one block so its text and shapes are not parsed as Markdown.
-+        svg = '\n'.join(line for line in svg.splitlines() if line.strip())
-+        fragments.append(f'<div class="chart-{theme} {scope}">\n{svg}\n</div>')
-+    return '\n'.join(fragments)
 +
 +
-+def walk(items, root):
++def walk(items):
 +    for item in items:
-+        chapter = item.get('Chapter')
++        chapter = item.get('Chapter') if isinstance(item, dict) else None
 +        if chapter:
-+            chapter['content'] = PICTURE.sub(lambda match: embed(match, root), chapter['content'])
-+            walk(chapter['sub_items'], root)
++            chapter['content'] = chapter['content'].replace('src="src/figures/', 'src="figures/')
++            walk(chapter['sub_items'])
 +
 +
 +def main():
 +    if len(sys.argv) > 1 and sys.argv[1] == 'supports':
 +        sys.exit(0 if len(sys.argv) > 2 and sys.argv[2] == 'html' else 1)
 +    context, book = json.load(sys.stdin)
-+    walk(book.get('items', book.get('sections', [])), Path(context['root']))
++    walk(book.get('items', book.get('sections', [])))
 +    json.dump(book, sys.stdout)
 +
 +
@@ theme/diagrams.css
  .mdbook-graphviz-output svg,
 -.mermaid svg {
 +.mermaid svg,
-+.chart-src svg {
++.chart-src img {
      display: block;
      max-width: 100%;
      height: auto;
@@ theme/diagrams.css
      .mdbook-graphviz-output svg,
 -    .mermaid svg {
 +    .mermaid svg,
-+    .chart-src svg {
++    .chart-src img {
          max-width: none;
      }
  }
@@ theme/diagrams.css: html:is(.coal, .navy, .ayu) .mdbook-graphviz-output [fill="b
      fill: #b7b7b7;
  }
 +
-+/* The build embeds both palettes as inline SVG. GitHub keeps the source
-+   picture; book themes select a palette without fetching another image. */
-+.chart-dark {
++/* Each chart has a light and a dark file, marked for GitHub by its URL
++   fragment; book themes select one the same way. */
++.chart-src img[src$="#gh-dark-mode-only"] {
 +    display: none;
 +}
 +
 +@media screen {
-+    html:is(.coal, .navy, .ayu) .chart-dark {
++    html:is(.coal, .navy, .ayu) .chart-src img[src$="#gh-dark-mode-only"] {
 +        display: block;
 +    }
 +
-+    html:is(.coal, .navy, .ayu) .chart-light {
++    html:is(.coal, .navy, .ayu) .chart-src img[src$="#gh-light-mode-only"] {
 +        display: none;
 +    }
 +}

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ACK ac4a500

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