diff --git a/package.json b/package.json
index 37b5aee..bf75f68 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "nostr_quantum_preparation",
-  "version": "0.1.6",
+  "version": "0.1.7",
   "description": "A migration strategy for bringing post-quantum security to Nostr without breaking the social graph, without requiring consensus on a single post-quantum algorithm, and without forcing existing users to abandon their identities.",
   "main": "index.js",
   "scripts": {
diff --git a/www/index.html b/www/index.html
index 79fbf6f..f23d148 100644
--- a/www/index.html
+++ b/www/index.html
@@ -162,6 +162,28 @@
       word-break: break-word;
     }
 
+    /* Mandatory entropy-collection state for the seed box. While collecting,
+       the box is an interactive zone (not a word grid): centered prompt,
+       crosshair cursor, focus outline for keyboard users. Once 64 events are
+       collected the .pq-seed-collecting class is removed and the box reverts
+       to the word-grid layout above. */
+    .pq-seed-display.pq-seed-collecting {
+      display: block;
+      min-height: 120px;
+      cursor: crosshair;
+      text-align: center;
+    }
+    .pq-seed-display.pq-seed-collecting:focus {
+      outline: 2px solid var(--accent-color);
+      outline-offset: 2px;
+    }
+    .pq-seed-collect-prompt {
+      font-size: 14px;
+      color: var(--primary-color);
+      line-height: 1.6;
+      padding: 18px 10px;
+    }
+
     .pq-seed-word { display: flex; align-items: center; gap: 8px; }
     .pq-seed-number { color: var(--muted-color); font-size: 12px; min-width: 20px; }
 
@@ -422,7 +444,23 @@
             <label style="margin-right: 12px;"><input type="radio" name="pqWordCount" value="256" id="pqWordCount24" checked> 24 words (recommended)</label>
             <label><input type="radio" name="pqWordCount" value="128" id="pqWordCount12"> 12 words (testing only)</label>
           </div>
-          <div class="pq-seed-display" id="pqSeedDisplay"></div>
+          <!--
+               Mandatory entropy collection zone.
+               Before generation: shows a prompt + progress bar and collects
+               mouse-move / keypress events. After 64 events the seed is
+               generated (CSPRNG + user entropy via SHA-256) and the box
+               switches to the word-grid layout. tabindex makes it keyboard-
+               focusable so laptop-only users can type into it.
+          -->
+          <div class="pq-seed-display pq-seed-collecting" id="pqSeedDisplay" tabindex="0">
+            <div class="pq-seed-collect-prompt" id="pqSeedCollectPrompt">
+              Move your mouse and/or press random keys inside this box to generate your seed phrase.
+              <div style="margin-top: 10px; height: 6px; background: var(--muted-color); border-radius: 3px; overflow: hidden;">
+                <div id="pqSeedEntropyBar" style="height: 100%; width: 0%; background: var(--accent-color); transition: width 0.2s;"></div>
+              </div>
+              <div id="pqSeedEntropyCount" style="margin-top: 6px; font-size: 12px; color: var(--muted-color);">0 / 64</div>
+            </div>
+          </div>
           <div class="pq-info-text" style="margin-top: 12px; font-size: 13px; color: var(--accent-color);">
             <strong>Verify out-of-band after linking:</strong> This seed phrase is your backup — but
             this browser cannot cryptographically prove the published PQ keys came from it. After completing
@@ -430,20 +468,6 @@
             independently, and confirm the public keys match the published event. This is the only way to
             catch a compromised browser that might have substituted attacker keys.
           </div>
-          <div class="pq-info-text" style="margin-top: 15px; font-size: 13px;">
-            <strong>Optional:</strong> Add extra entropy by moving your mouse and typing in the box below.
-            This mixes your input with the browser's random number generator, making the seed unpredictable
-            even if the browser's RNG is compromised. You can skip this — a seed has already been generated for you above.
-          </div>
-          <div id="pqEntropyBox" style="background: var(--secondary-color); color: var(--primary-color); border: var(--border); border-radius: var(--border-radius); padding: 15px; font-size: 13px; min-height: 60px; margin: 10px 0; cursor: text; text-align: left;" tabindex="0">
-            <span id="pqEntropyHint">Optional: click here and type random characters, move your mouse to add entropy...</span>
-            <div style="margin-top: 8px; height: 6px; background: var(--muted-color); border-radius: 3px; overflow: hidden;">
-              <div id="pqEntropyBar" style="height: 100%; width: 0%; background: var(--accent-color); transition: width 0.2s;"></div>
-            </div>
-          </div>
-          <div class="pq-button-row">
-            <button class="pq-button pq-button-secondary pq-hidden" id="pqRegenerateWithEntropyBtn" disabled>Generate with Extra Entropy</button>
-          </div>
           <label class="pq-checkbox-row">
             <input type="checkbox" id="pqSeedConfirmed" />
             I have written down my seed phrase
diff --git a/www/js/index-app.mjs b/www/js/index-app.mjs
index 3739bdb..464774d 100644
--- a/www/js/index-app.mjs
+++ b/www/js/index-app.mjs
@@ -1,5 +1,4 @@
     import {
-      generateSeedPhrase,
       generateSeedPhraseWithEntropy,
       mnemonicToSeed,
       isValidMnemonic,
@@ -452,26 +451,93 @@
     /* ================================================================
        STEP 2: SEED PHRASE
        ================================================================ */
+    // Mandatory user-entropy collection. The seed box (pqSeedDisplay) is the
+    // collection zone: the user must move their mouse and/or press keys inside
+    // it until ENTROPY_REQUIRED_EVENTS samples are gathered. The seed is then
+    // generated by mixing CSPRNG output with the collected user entropy via
+    // SHA-256 (generateSeedPhraseWithEntropy), so the seed stays unpredictable
+    // even if the browser's CSPRNG is compromised. Either mouse or keyboard
+    // input counts toward the total, so laptop-only users aren't blocked.
+    const ENTROPY_REQUIRED_EVENTS = 256; // ~512 bits of true user entropy
+    // Minimum interval between accepted mousemove samples (ms). Browsers fire
+    // mousemove at ~60-1000+ Hz; spacing samples out reduces correlation
+    // between consecutive deltas (each sample carries more independent
+    // hand-jitter), increasing the true entropy per sample.
+    const MOUSE_SAMPLE_MIN_INTERVAL_MS = 32;
     let userEntropyChunks = [];
-    let entropyCollecting = false;
+    let entropyCollected = 0;
+    let entropyListenersBound = false;
+    // Last mouse position, used to capture deltas (dx, dy) which hold the
+    // unpredictable hand-jitter entropy better than absolute coordinates.
+    let lastMouseX = null;
+    let lastMouseY = null;
+    // Timestamp of the last accepted mousemove sample (for throttling).
+    let lastMouseSampleTime = 0;
 
     function getSelectedEntropyBits() {
       const radio = document.querySelector('input[name="pqWordCount"]:checked');
       return radio ? parseInt(radio.value, 10) : 256;
     }
 
+    // Render the seed box in its collecting (pre-generation) state.
+    function renderSeedCollectingState() {
+      pqSeedDisplay.classList.add('pq-seed-collecting');
+      pqSeedDisplay.innerHTML =
+        '<div class="pq-seed-collect-prompt" id="pqSeedCollectPrompt">'
+        + 'Move your mouse and/or press random keys inside this box to generate your seed phrase.'
+        + '<div style="margin-top: 10px; height: 6px; background: var(--muted-color); border-radius: 3px; overflow: hidden;">'
+        + '<div id="pqSeedEntropyBar" style="height: 100%; width: 0%; background: var(--accent-color); transition: width 0.2s;"></div>'
+        + '</div>'
+        + '<div id="pqSeedEntropyCount" style="margin-top: 6px; font-size: 12px; color: var(--muted-color);">0 / '
+        + ENTROPY_REQUIRED_EVENTS + '</div>'
+        + '</div>';
+      const bar = document.getElementById('pqSeedEntropyBar');
+      if (bar) bar.style.width = '0%';
+    }
+
+    function updateEntropyProgress() {
+      const bar = document.getElementById('pqSeedEntropyBar');
+      const count = document.getElementById('pqSeedEntropyCount');
+      const pct = Math.min(100, Math.round((entropyCollected / ENTROPY_REQUIRED_EVENTS) * 100));
+      if (bar) bar.style.width = pct + '%';
+      if (count) count.textContent = `${entropyCollected} / ${ENTROPY_REQUIRED_EVENTS}`;
+    }
+
+    // Collect low-entropy environment/fingerprint values and mix them into the
+    // seed. Each of these is low-entropy on its own (and a remote attacker can
+    // often query the same values), but together they add a few extra bits and
+    // cost nothing. They are mixed via SHA-256 alongside the CSPRNG and user
+    // input, so they can only help, never hurt.
+    function collectSystemEntropy() {
+      const parts = [];
+      try { parts.push('ua:' + navigator.userAgent); } catch (e) {}
+      try { parts.push('plat:' + navigator.platform); } catch (e) {}
+      try { parts.push('lang:' + navigator.language); } catch (e) {}
+      try { parts.push('langs:' + (navigator.languages || []).join(',')); } catch (e) {}
+      try { parts.push('sw:' + screen.width); } catch (e) {}
+      try { parts.push('sh:' + screen.height); } catch (e) {}
+      try { parts.push('scd:' + screen.colorDepth); } catch (e) {}
+      try { parts.push('dpr:' + window.devicePixelRatio); } catch (e) {}
+      try { parts.push('hwc:' + navigator.hardwareConcurrency); } catch (e) {}
+      try { parts.push('mem:' + navigator.deviceMemory); } catch (e) {}
+      try { parts.push('tz:' + Intl.DateTimeFormat().resolvedOptions().timeZone); } catch (e) {}
+      // performance.now() at collection time adds a little timing jitter.
+      try { parts.push('now:' + performance.now()); } catch (e) {}
+      return parts.join('|');
+    }
+
+    // Generate the seed from the collected user entropy + system entropy +
+    // CSPRNG and reveal the word grid in the same box.
     function generateAndShowSeed() {
       const entropyBits = getSelectedEntropyBits();
-      // Use user entropy if available, otherwise pure CSPRNG
-      if (userEntropyChunks.length > 0) {
-        const userEntropy = new TextEncoder().encode(userEntropyChunks.join(''));
-        pqMnemonic = generateSeedPhraseWithEntropy(userEntropy, entropyBits);
-        otsLog(`Seed generated with ${userEntropyChunks.length} entropy chunks from user input (${entropyBits}-bit).`);
-      } else {
-        pqMnemonic = generateSeedPhrase(entropyBits);
-        otsLog(`Seed generated (${entropyBits}-bit).`);
-      }
+      // Prepend system entropy so it is always mixed in, regardless of how
+      // many mouse/keyboard samples were collected.
+      const combined = collectSystemEntropy() + '\n' + userEntropyChunks.join('\n');
+      const userEntropy = new TextEncoder().encode(combined);
+      pqMnemonic = generateSeedPhraseWithEntropy(userEntropy, entropyBits);
+      otsLog(`Seed generated with ${userEntropyChunks.length} user entropy samples + system entropy (${entropyBits}-bit).`);
       const words = pqMnemonic.split(' ');
+      pqSeedDisplay.classList.remove('pq-seed-collecting');
       pqSeedDisplay.innerHTML = words.map((word, i) =>
         `<div class="pq-seed-word"><span class="pq-seed-number">${i + 1}.</span>${word}</div>`
       ).join('');
@@ -479,46 +545,70 @@
       pqSeedContinueBtn.disabled = true;
     }
 
-    // Entropy collection from mouse and keyboard (optional)
-    function startEntropyCollection() {
-      const entropyBox = document.getElementById('pqEntropyBox');
-      const entropyBar = document.getElementById('pqEntropyBar');
-      const entropyHint = document.getElementById('pqEntropyHint');
-      const regenWithEntropyBtn = document.getElementById('pqRegenerateWithEntropyBtn');
-      const maxChunks = 64; // collect up to 64 events
-      let collected = 0;
+    // Reset the collection zone to its pre-generation state and (re)bind the
+    // mouse/keyboard listeners. Called when entering step 2, switching word
+    // counts, or switching back to the "Generate New Seed" panel.
+    function resetSeedCollection() {
+      userEntropyChunks = [];
+      entropyCollected = 0;
+      lastMouseX = null;
+      lastMouseY = null;
+      lastMouseSampleTime = 0;
+      pqMnemonic = null;
+      pqSeedConfirmed.checked = false;
+      pqSeedContinueBtn.disabled = true;
+      renderSeedCollectingState();
+      updateEntropyProgress();
+      bindEntropyListeners();
+    }
 
-      function updateBar() {
-        const pct = Math.min(100, Math.round((collected / maxChunks) * 100));
-        entropyBar.style.width = pct + '%';
-        if (collected >= maxChunks) {
-          entropyHint.textContent = 'Enough entropy collected. Click "Generate with Extra Entropy" to use it.';
-        } else if (collected > 0) {
-          entropyHint.textContent = `Collected ${collected}/${maxChunks} entropy samples. Keep going, or click "Generate with Extra Entropy" to use what you have.`;
-        }
-        // Show the "Generate with Extra Entropy" button once we have at least 1 chunk
-        if (collected > 0 && regenWithEntropyBtn) {
-          regenWithEntropyBtn.classList.remove('pq-hidden');
-          regenWithEntropyBtn.disabled = false;
-        }
-      }
+    // Bind mouse/keyboard collection listeners to the seed box. Idempotent.
+    function bindEntropyListeners() {
+      if (entropyListenersBound) return;
+      entropyListenersBound = true;
 
       function collectEvent(data) {
-        if (collected >= maxChunks) return;
-        userEntropyChunks.push(data + ':' + Date.now() + ':' + Math.random());
-        collected++;
-        updateBar();
+        if (entropyCollected >= ENTROPY_REQUIRED_EVENTS) return;
+        // performance.now() gives sub-millisecond monotonic timing jitter,
+        // which is harder for a remote attacker to predict than Date.now().
+        userEntropyChunks.push(data + ':' + performance.now() + ':' + Math.random());
+        entropyCollected++;
+        updateEntropyProgress();
+        if (entropyCollected >= ENTROPY_REQUIRED_EVENTS) {
+          // Threshold reached — generate the seed immediately.
+          generateAndShowSeed();
+        }
       }
 
-      entropyBox.addEventListener('mousemove', (e) => {
-        collectEvent(`m${e.clientX},${e.clientY}`);
+      pqSeedDisplay.addEventListener('mousemove', (e) => {
+        // Throttle: only accept a sample if enough time has passed since the
+        // last one. This doubles the effective interval between samples
+        // (browsers normally fire at ~16ms/frame), reducing correlation
+        // between consecutive deltas so each accepted sample carries more
+        // independent entropy.
+        const now = performance.now();
+        if (now - lastMouseSampleTime < MOUSE_SAMPLE_MIN_INTERVAL_MS) return;
+        lastMouseSampleTime = now;
+        // Capture deltas (dx, dy) between consecutive samples rather than
+        // absolute coordinates. The micro-jitter in deltas is the real
+        // unpredictable entropy in mouse movement; absolute positions are
+        // highly correlated between samples and bounded by the box size.
+        const dx = lastMouseX === null ? 0 : e.clientX - lastMouseX;
+        const dy = lastMouseY === null ? 0 : e.clientY - lastMouseY;
+        lastMouseX = e.clientX;
+        lastMouseY = e.clientY;
+        collectEvent(`m${dx},${dy}`);
       });
-      entropyBox.addEventListener('keypress', (e) => {
+      pqSeedDisplay.addEventListener('keypress', (e) => {
         collectEvent(`k${e.key}:${e.keyCode}`);
       });
-      entropyBox.addEventListener('keydown', (e) => {
-        // Also capture non-printable keys
-        if (e.key.length > 1) collectEvent(`k${e.key}:${e.keyCode}`);
+      pqSeedDisplay.addEventListener('keydown', (e) => {
+        // Capture non-printable keys too (Arrow, Shift, etc.). Prevent default
+        // scrolling/behavior when the box is focused and still collecting.
+        if (entropyCollected < ENTROPY_REQUIRED_EVENTS) {
+          if (e.key.length > 1) e.preventDefault();
+          collectEvent(`k${e.key}:${e.keyCode}`);
+        }
       });
     }
 
@@ -528,16 +618,8 @@
       document.getElementById('pqSeedOwnPanel').style.display = 'none';
       document.getElementById('pqSeedToggleGenerate').classList.add('pq-seed-toggle-active');
       document.getElementById('pqSeedToggleOwn').classList.remove('pq-seed-toggle-active');
-      // Generate a fresh seed when switching to the generate panel
-      userEntropyChunks = [];
-      generateAndShowSeed();
-      // Reset the entropy UI
-      const entropyBar = document.getElementById('pqEntropyBar');
-      const entropyHint = document.getElementById('pqEntropyHint');
-      const regenWithEntropyBtn = document.getElementById('pqRegenerateWithEntropyBtn');
-      if (entropyBar) entropyBar.style.width = '0%';
-      if (entropyHint) entropyHint.textContent = 'Optional: click here and type random characters, move your mouse to add entropy...';
-      if (regenWithEntropyBtn) { regenWithEntropyBtn.classList.add('pq-hidden'); regenWithEntropyBtn.disabled = true; }
+      // Entering / re-entering the generate panel resets the collection zone.
+      resetSeedCollection();
     }
 
     function showSeedOwnPanel() {
@@ -887,29 +969,21 @@
     });
 
     document.getElementById('pqStartBtn').addEventListener('click', () => {
-      userEntropyChunks = [];
-      generateAndShowSeed();
       showView('pqSeedStep');
       setStepActive(2);
-      startEntropyCollection();
+      // Reset the collection zone and start mandatory mouse/keyboard collection.
+      resetSeedCollection();
     });
 
     // Seed mode toggle
     document.getElementById('pqSeedToggleGenerate').addEventListener('click', () => showSeedGeneratePanel());
     document.getElementById('pqSeedToggleOwn').addEventListener('click', () => showSeedOwnPanel());
 
-    // Word-count selector: regenerate when the user switches between 12/24 words
+    // Word-count selector: switching 12/24 words resets the collection zone
+    // so the user re-collects entropy for the new word count.
     document.querySelectorAll('input[name="pqWordCount"]').forEach((radio) => {
       radio.addEventListener('change', () => {
-        userEntropyChunks = [];
-        generateAndShowSeed();
-        // Reset entropy UI
-        const entropyBar = document.getElementById('pqEntropyBar');
-        const entropyHint = document.getElementById('pqEntropyHint');
-        const regenWithEntropyBtn = document.getElementById('pqRegenerateWithEntropyBtn');
-        if (entropyBar) entropyBar.style.width = '0%';
-        if (entropyHint) entropyHint.textContent = 'Optional: click here and type random characters, move your mouse to add entropy...';
-        if (regenWithEntropyBtn) { regenWithEntropyBtn.classList.add('pq-hidden'); regenWithEntropyBtn.disabled = true; }
+        resetSeedCollection();
       });
     });
 
@@ -951,9 +1025,6 @@
       }
     });
 
-    // "Generate with Extra Entropy" — generates a fresh seed mixing CSPRNG + user entropy
-    document.getElementById('pqRegenerateWithEntropyBtn').addEventListener('click', () => { generateAndShowSeed(); });
-
     pqSeedConfirmed.addEventListener('change', () => { pqSeedContinueBtn.disabled = !pqSeedConfirmed.checked; });
     pqSeedContinueBtn.addEventListener('click', () => { setStepDone(2); derivePQKeys(); });
     pqDeriveContinueBtn.addEventListener('click', () => { showView('pqSignStep'); setStepActive(4); });
@@ -1093,17 +1164,21 @@
       pqEvent = null;
       kind1Event = null; // F-L1: clear all secret references
       userEntropyChunks = [];
+      entropyCollected = 0;
+      lastMouseX = null;
+      lastMouseY = null;
+      lastMouseSampleTime = 0;
       pendingOtsBytes = null;
       currentBlockHeight = 0;
       pqRelays = DEFAULT_RELAYS.slice();
 
-      // G56-10: Clear DOM elements that displayed secret material
+      // G56-10: Clear DOM elements that displayed secret material.
+      // Reset the seed box to its collecting (pre-generation) state so no
+      // generated words remain visible after sign-out.
       const seedDisplay = document.getElementById('pqSeedDisplay');
-      if (seedDisplay) seedDisplay.innerHTML = '';
+      if (seedDisplay) renderSeedCollectingState();
       const seedInput = document.getElementById('pqSeedInput');
       if (seedInput) seedInput.value = '';
-      const entropyHint = document.getElementById('pqEntropyHint');
-      if (entropyHint) entropyHint.textContent = 'Optional: click here and type random characters, move your mouse to add entropy...';
 
       // G56-10: Clear the clipboard (in case the user copied the seed phrase)
       try { navigator.clipboard.writeText(''); } catch (e) { /* clipboard may not be available */ }
diff --git a/www/js/version.json b/www/js/version.json
index 00cf3a3..b978e0c 100644
--- a/www/js/version.json
+++ b/www/js/version.json
@@ -1,5 +1,5 @@
 {
-  "VERSION": "v0.1.6",
-  "VERSION_NUMBER": "0.1.6",
-  "BUILD_DATE": "2026-07-30T10:46:55.076Z"
+  "VERSION": "v0.1.7",
+  "VERSION_NUMBER": "0.1.7",
+  "BUILD_DATE": "2026-07-31T10:14:20.015Z"
 }