diff --git a/.github/workflows/leak-guard.yml b/.github/workflows/leak-guard.yml
new file mode 100644
index 0000000..ed8efb4
--- /dev/null
+++ b/.github/workflows/leak-guard.yml
@@ -0,0 +1,35 @@
+name: leak-guard
+
+# Self-contained public-repo leak gate. Public CI cannot reach the private
+# tooling, so this encodes only the generic net: internal-infra references,
+# tracked CLAUDE.md/.claude paths, and AI-attribution in commit messages.
+# No project-specific reverse-engineering vocabulary lives here.
+
+on: [push, pull_request]
+
+jobs:
+  leak-guard:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+      - name: Compute commit range
+        id: range
+        run: |
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            base="${{ github.event.pull_request.base.sha }}"
+            head="${{ github.event.pull_request.head.sha }}"
+            echo "range=$base..$head" >> "$GITHUB_OUTPUT"
+          else
+            before="${{ github.event.before }}"
+            after="${{ github.sha }}"
+            # New branch / first push: github.event.before is all-zeros.
+            if [ -z "$before" ] || [ "$before" = "0000000000000000000000000000000000000000" ]; then
+              echo "range=$after" >> "$GITHUB_OUTPUT"
+            else
+              echo "range=$before..$after" >> "$GITHUB_OUTPUT"
+            fi
+          fi
+      - name: Run leak-guard
+        run: bash ci/leak-guard.sh "${{ steps.range.outputs.range }}"
diff --git a/.gitignore b/.gitignore
index 96ef6c0..563c7ea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,9 @@
 /target
 Cargo.lock
+
+# session scratch — never track (may contain RE breadcrumbs)
+scratch/
+
+# internal agent context — never publish (leak-guard blocks both)
+CLAUDE.md
+.claude/
diff --git a/Cargo.toml b/Cargo.toml
index ff36fd5..775ec0d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "freemkv-keysources"
-version = "0.30.0"
+version = "0.31.0"
 edition = "2024"
 license = "AGPL-3.0-only"
 description = "Pluggable AACS key sources (keydb, online key service, mapfile) for libfreemkv. Each source looks a disc up and hands libfreemkv a Key; the library does all derivation."
@@ -10,8 +10,12 @@ categories = ["multimedia"]
 
 [dependencies]
 # The crate provides the `KeySource` trait + `Key`/`DiscInputs` types these impls fill.
-libfreemkv = "0.30"
+libfreemkv = "0.31"
 # OnlineSource: POST disc inputs + samples to a key service over HTTP.
 ureq = { version = "2", features = ["json"] }
 serde_json = "1"
 base64 = "0.22"
+
+[profile.release]
+lto = "thin"
+codegen-units = 1
diff --git a/ci/leak-guard.sh b/ci/leak-guard.sh
new file mode 100755
index 0000000..b44cb91
--- /dev/null
+++ b/ci/leak-guard.sh
@@ -0,0 +1,120 @@
+#!/usr/bin/env bash
+#
+# leak-guard.sh — self-contained public-repo leak gate.
+#
+# This is the LAST line of defense in CI. It is intentionally self-contained:
+# public CI cannot reach the private tooling, so this script encodes ONLY the
+# generic net — internal infrastructure references, agent-context files, and
+# AI-attribution in commit messages. It deliberately contains NO project-
+# specific reverse-engineering vocabulary (those words would themselves be a
+# leak). The richer private scanner stays private.
+#
+# Fails (exit 1) if any of the following appear in the repo:
+#   1. a tracked CLAUDE.md or .claude/ path (agent context — never public),
+#   2. tracked file content matching the internal-infra net,
+#   3. a commit message (in the given range) with AI attribution.
+#
+# Usage:
+#   leak-guard.sh [<commit-range>]
+#     <commit-range>  optional git rev-list range to scan commit messages
+#                     (e.g. "abc..def"). If omitted, commit-message scan is
+#                     skipped (path + content checks always run).
+
+set -euo pipefail
+
+# Absolute path to this script, resolved before any cd, so we can exclude it
+# from the content scan (it necessarily contains the detection patterns).
+SELF_ABS="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/$(basename "${BASH_SOURCE[0]}")"
+
+REPO="$(git rev-parse --show-toplevel)"
+cd "$REPO"
+
+fail=0
+note() { printf '  ✗ %s\n' "$1"; fail=1; }
+
+# Internal-infra net — GENERIC ONLY. This script ships in the public repo, so
+# the patterns themselves must not name any org-specific identifier (doing so
+# would itself leak the infra they guard). We catch the leak *class*:
+#   - RFC1918 private IPv4 ranges (10/8, 172.16/12, 192.168/16),
+#   - private/internal/non-routable TLDs (.internal/.local/.lan/.corp/.invalid),
+#   - docker.internal.
+# The full org-specific net (literal hostnames, service names, repo paths,
+# vendor tooling, …) lives ONLY in the private scanner and never ships here.
+INFRA_RE='\b10\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}|\b172\.(1[6-9]|2[0-9]|3[01])\.[0-9]{1,3}\.[0-9]{1,3}|\b192\.168\.[0-9]{1,3}\.[0-9]{1,3}|\.internal\b|\.local\b|\.lan\b|\.corp\b|\.invalid\b|docker\.internal'
+# Home-path net — GENERIC ONLY. Catches an absolute developer home path
+# committed into a tracked file (a macOS /Users/<user>/… or Linux /home/<user>/…
+# path). This names NO specific user — it matches the leak *class* (any home
+# path), so the pattern itself reveals nothing org- or person-specific. A real
+# leak (e.g. /Users/alice/Developer/x slipping into a public RELEASE.md) trips
+# this regardless of whose machine it came from. The username segment is a
+# literal-username class ([A-Za-z0-9._-]) so dynamic/templated paths that build
+# the user at runtime — shell `/home/$USER/`, doc `/home/<rip>/`, Rust
+# `/home/{user}/` — do NOT false-positive; only a baked-in literal home leaks.
+HOMEPATH_RE='/Users/[A-Za-z0-9._-]+/|/home/[A-Za-z0-9._-]+/'
+# AI-attribution net (case-insensitive). "claude" matches only as a standalone
+# word — NOT preceded by a dot/slash/alnum and NOT followed by .md — so legit
+# mentions of CLAUDE.md / .claude/ in a commit message don't false-positive.
+ATTR_RE='co-authored-by|generated with|🤖|(?<![.\/A-Za-z0-9])claude(?!\.md)'
+
+echo "── leak-guard: tracked agent-context paths ──"
+while IFS= read -r f; do
+  case "$f" in
+    CLAUDE.md|*/CLAUDE.md|.claude|.claude/*|*/.claude|*/.claude/*)
+      note "tracked agent-context file: $f (CLAUDE.md/.claude must never be tracked in a public repo)" ;;
+  esac
+done < <(git ls-files)
+
+# Match a PCRE against a file, emitting "LINE: MATCH". The pattern is passed as
+# an argument (not interpolated into a //) so metacharacters like the "/" in a
+# path-style token can't break the regex. Reads raw bytes so non-UTF-8 blobs
+# don't abort the scan.
+pcre_matches() {
+  perl -e '
+    my ($file, $re) = @ARGV;
+    open(my $fh, "<:raw", $file) or exit 0;
+    my $rx; eval { $rx = qr/$re/i }; exit 0 if $@;
+    while (my $l = <$fh>) { if ($l =~ /$rx/) { print "$.: $&\n"; } }
+  ' "$1" "$2" 2>/dev/null
+}
+
+# This script's own source necessarily contains the detection patterns (e.g.
+# the regex tokens in INFRA_RE), so scanning it would always self-flag. Skip it.
+SELF="$(git ls-files --full-name -- "$SELF_ABS" 2>/dev/null | head -1)"
+
+echo "── leak-guard: internal-infra references in tracked files ──"
+while IFS= read -r f; do
+  case "$f" in *.png|*.jpg|*.jpeg|*.ico|*.gif|*.bin|*.crate|*.gz|*.zip|*.pdf) continue ;; esac
+  [ -n "$SELF" ] && [ "$f" = "$SELF" ] && continue
+  [ -f "$f" ] || continue
+  while IFS= read -r hit; do
+    [ -z "$hit" ] && continue
+    note "internal-infra reference: $f:$hit"
+  done < <(pcre_matches "$f" "$INFRA_RE")
+  while IFS= read -r hit; do
+    [ -z "$hit" ] && continue
+    note "[HOME-PATH] absolute home path: $f:$hit (no local home path may be committed to a public repo)"
+  done < <(pcre_matches "$f" "$HOMEPATH_RE")
+done < <(git ls-files)
+
+RANGE="${1:-}"
+if [ -n "$RANGE" ]; then
+  echo "── leak-guard: AI-attribution in commit messages ($RANGE) ──"
+  while IFS= read -r sha; do
+    [ -z "$sha" ] && continue
+    msg="$(git log -1 --format='%B' "$sha" 2>/dev/null || true)"
+    # Pass the pattern as an argument (not interpolated into a //) so the
+    # lookbehind char class and "/" don't break the regex.
+    hit="$(printf '%s' "$msg" | perl -e '
+      my $re = $ARGV[0]; my $rx = qr/$re/i;
+      while (my $l = <STDIN>) { if ($l =~ /($rx)/) { print "$1\n"; last; } }
+    ' "$ATTR_RE" | head -1 || true)"
+    [ -n "$hit" ] && note "commit ${sha:0:12}: message contains \"$hit\" (owner rule: zero AI attribution, ever)"
+  done < <(git rev-list "$RANGE" 2>/dev/null || true)
+fi
+
+echo
+if [ "$fail" -ne 0 ]; then
+  echo "✗ leak-guard: blocking finding(s) above — DO NOT MERGE/PUBLISH"
+  exit 1
+fi
+echo "✓ leak-guard: clean"