diff --git a/mobile/package.json b/mobile/package.json
index 163e7c5..40cd5dd 100644
--- a/mobile/package.json
+++ b/mobile/package.json
@@ -23,6 +23,7 @@
     "@capacitor/screen-orientation": "^6.0.0",
     "@capacitor/share": "^6.0.0",
     "@capacitor/splash-screen": "^6.0.0",
-    "@capacitor/status-bar": "^6.0.0"
+    "@capacitor/status-bar": "^6.0.0",
+    "capacitor-secure-storage-plugin": "^0.10.0"
   }
 }
diff --git a/public/index.html b/public/index.html
index 8f9616b..969d628 100644
--- a/public/index.html
+++ b/public/index.html
@@ -422,6 +422,7 @@
   <script defer src="/js/transcriptionSettings.js"></script>
   <script defer src="/js/voicePreferences.js"></script>
   <script defer src="/js/app.js"></script>
+  <script defer src="/js/secureStorage.js"></script>
   <script defer src="/js/auth.js"></script>
   <script defer src="/js/liveEncounter.js"></script>
   <script defer src="/js/voiceDictation.js"></script>
diff --git a/public/js/auth.js b/public/js/auth.js
index 8489882..bc8a03f 100644
--- a/public/js/auth.js
+++ b/public/js/auth.js
@@ -33,7 +33,10 @@ document.addEventListener('DOMContentLoaded', function() {
   if (ssoOk === 'ok') {
     var ssoSid = urlParams.get('sid');
     history.replaceState(null, '', window.location.pathname);
-    if (ssoSid) localStorage.setItem(SESSION_KEY, ssoSid);
+    if (ssoSid) {
+      if (window.SecureStorage) window.SecureStorage.set(SESSION_KEY, ssoSid);
+      else localStorage.setItem(SESSION_KEY, ssoSid);
+    }
     // Token is in httpOnly cookie — verify via /me endpoint (cookie sent automatically)
     fetch('/api/auth/me', { credentials: 'same-origin' })
       .then(function(r) { if (r.ok) return r.json(); throw new Error('invalid'); })
@@ -72,36 +75,43 @@ document.addEventListener('DOMContentLoaded', function() {
     })
     .catch(function() {});
 
-  var savedToken = localStorage.getItem(TOKEN_KEY);
-  if (ssoOk) {
-    // SSO handled above — do nothing here
-  } else if (ssoError) {
-    // SSO error handled above — auth screen already shown
-  } else if (savedToken) {
-    // Existing token — verify silently; auth screen stays hidden during check
-    fetch('/api/auth/me', {
-      headers: { 'Authorization': 'Bearer ' + savedToken }
-    })
-    .then(function(r) {
-      if (r.ok) return r.json();
-      throw new Error('expired');
-    })
-    .then(function(data) {
-      if (data && data.user) {
-        enterApp(data.user, savedToken);
-      } else {
+  var hydrate = window.SecureStorage
+    ? window.SecureStorage.hydrate([TOKEN_KEY, USER_KEY, SESSION_KEY])
+    : Promise.resolve();
+
+  hydrate.then(function() {
+    var savedToken = window.SecureStorage
+      ? window.SecureStorage.getSync(TOKEN_KEY)
+      : localStorage.getItem(TOKEN_KEY);
+
+    if (ssoOk) {
+      // SSO handled above — do nothing here
+    } else if (ssoError) {
+      // SSO error handled above — auth screen already shown
+    } else if (savedToken) {
+      fetch('/api/auth/me', {
+        headers: { 'Authorization': 'Bearer ' + savedToken }
+      })
+      .then(function(r) {
+        if (r.ok) return r.json();
+        throw new Error('expired');
+      })
+      .then(function(data) {
+        if (data && data.user) {
+          enterApp(data.user, savedToken);
+        } else {
+          showAuthScreen();
+          clearSession();
+        }
+      })
+      .catch(function() {
         showAuthScreen();
         clearSession();
-      }
-    })
-    .catch(function() {
+      });
+    } else {
       showAuthScreen();
-      clearSession();
-    });
-  } else {
-    // No token — show login immediately
-    showAuthScreen();
-  }
+    }
+  });
 
   // ---- HELPER FUNCTIONS ----
 
@@ -125,8 +135,13 @@ document.addEventListener('DOMContentLoaded', function() {
 
   function enterApp(user, token) {
     window.AUTH_TOKEN = token;
-    localStorage.setItem(TOKEN_KEY, token);
-    localStorage.setItem(USER_KEY, JSON.stringify(user));
+    if (window.SecureStorage) {
+      window.SecureStorage.set(TOKEN_KEY, token);
+      window.SecureStorage.set(USER_KEY, JSON.stringify(user));
+    } else {
+      localStorage.setItem(TOKEN_KEY, token);
+      localStorage.setItem(USER_KEY, JSON.stringify(user));
+    }
 
     if (authScreen) authScreen.style.display = 'none';
     if (mainApp) {
@@ -191,16 +206,25 @@ document.addEventListener('DOMContentLoaded', function() {
   }
 
   function clearSession() {
-    localStorage.removeItem(TOKEN_KEY);
-    localStorage.removeItem(USER_KEY);
-    localStorage.removeItem(SESSION_KEY);
+    if (window.SecureStorage) {
+      window.SecureStorage.remove(TOKEN_KEY);
+      window.SecureStorage.remove(USER_KEY);
+      window.SecureStorage.remove(SESSION_KEY);
+    } else {
+      localStorage.removeItem(TOKEN_KEY);
+      localStorage.removeItem(USER_KEY);
+      localStorage.removeItem(SESSION_KEY);
+    }
     window.AUTH_TOKEN = null;
   }
 
   window.getAuthHeaders = function() {
+    var token = window.AUTH_TOKEN;
+    if (!token && window.SecureStorage) token = window.SecureStorage.getSync(TOKEN_KEY);
+    if (!token) { try { token = localStorage.getItem(TOKEN_KEY); } catch(e) {} }
     return {
       'Content-Type': 'application/json',
-      'Authorization': 'Bearer ' + (window.AUTH_TOKEN || localStorage.getItem(TOKEN_KEY) || '')
+      'Authorization': 'Bearer ' + (token || '')
     };
   };
 
@@ -383,7 +407,10 @@ document.addEventListener('DOMContentLoaded', function() {
         }
 
         if (data.success && data.token && data.user) {
-          if (data.sessionId) localStorage.setItem(SESSION_KEY, data.sessionId);
+          if (data.sessionId) {
+            if (window.SecureStorage) window.SecureStorage.set(SESSION_KEY, data.sessionId);
+            else localStorage.setItem(SESSION_KEY, data.sessionId);
+          }
           enterApp(data.user, data.token);
           showToast('Welcome, ' + data.user.name + '!', 'success');
         } else {
@@ -473,7 +500,10 @@ document.addEventListener('DOMContentLoaded', function() {
         hideLoading();
 
         if (data.success && data.token && data.user) {
-          if (data.sessionId) localStorage.setItem(SESSION_KEY, data.sessionId);
+          if (data.sessionId) {
+            if (window.SecureStorage) window.SecureStorage.set(SESSION_KEY, data.sessionId);
+            else localStorage.setItem(SESSION_KEY, data.sessionId);
+          }
           enterApp(data.user, data.token);
           showToast(data.message || 'Account created!', 'success');
         } else if (data.success && data.needsVerification) {
@@ -555,7 +585,7 @@ document.addEventListener('DOMContentLoaded', function() {
           list.innerHTML = '<p style="color:var(--g400);font-size:13px;">No active sessions found.</p>';
           return;
         }
-        var currentSid = data.currentSessionId || localStorage.getItem(SESSION_KEY);
+        var currentSid = data.currentSessionId || (window.SecureStorage ? window.SecureStorage.getSync(SESSION_KEY) : localStorage.getItem(SESSION_KEY));
         list.innerHTML = data.sessions.map(function(s) {
           var isCurrent = s.id === currentSid;
           var created = new Date(s.created_at).toLocaleDateString();
diff --git a/public/js/documents.js b/public/js/documents.js
index b46ca2b..480e02e 100644
--- a/public/js/documents.js
+++ b/public/js/documents.js
@@ -64,7 +64,7 @@
     showLoading('Uploading document...');
     fetch('/api/documents/upload', {
       method: 'POST',
-      headers: { 'Authorization': 'Bearer ' + (window.AUTH_TOKEN || localStorage.getItem('ped_scribe_token') || '') },
+      headers: { 'Authorization': 'Bearer ' + (window.AUTH_TOKEN || (window.SecureStorage && window.SecureStorage.getSync('ped_scribe_token')) || localStorage.getItem('ped_scribe_token') || '') },
       body: formData
     })
     .then(function(r) { return r.json(); })
diff --git a/public/js/secureStorage.js b/public/js/secureStorage.js
new file mode 100644
index 0000000..d4eb503
--- /dev/null
+++ b/public/js/secureStorage.js
@@ -0,0 +1,73 @@
+// ============================================================
+// SECURE STORAGE WRAPPER
+// Browser: localStorage
+// Capacitor mobile: iOS Keychain / Android EncryptedSharedPreferences
+// via capacitor-secure-storage-plugin
+// ============================================================
+(function() {
+  var memCache = {};
+
+  function isNative() {
+    try {
+      return !!(window.Capacitor && typeof window.Capacitor.isNativePlatform === 'function' && window.Capacitor.isNativePlatform());
+    } catch(e) { return false; }
+  }
+
+  function plugin() {
+    try {
+      var p = window.Capacitor && window.Capacitor.Plugins && window.Capacitor.Plugins.SecureStoragePlugin;
+      return p || null;
+    } catch(e) { return null; }
+  }
+
+  window.SecureStorage = {
+    isNative: isNative,
+
+    get: function(key) {
+      if (isNative() && plugin()) {
+        return plugin().get({ key: key })
+          .then(function(r) { memCache[key] = r.value; return r.value; })
+          .catch(function() { return null; });
+      }
+      try { return Promise.resolve(localStorage.getItem(key)); } catch(e) { return Promise.resolve(null); }
+    },
+
+    set: function(key, value) {
+      memCache[key] = value;
+      if (isNative() && plugin()) {
+        return plugin().set({ key: key, value: value }).catch(function() {});
+      }
+      try { localStorage.setItem(key, value); } catch(e) {}
+      return Promise.resolve();
+    },
+
+    remove: function(key) {
+      delete memCache[key];
+      if (isNative() && plugin()) {
+        var p = plugin().remove({ key: key }).catch(function() {});
+        // Also clear legacy localStorage copy if any
+        try { localStorage.removeItem(key); } catch(e) {}
+        return p;
+      }
+      try { localStorage.removeItem(key); } catch(e) {}
+      return Promise.resolve();
+    },
+
+    // Synchronous read for hot paths (fetch headers). On native returns cached
+    // value populated by prior get/set. On web reads localStorage directly.
+    getSync: function(key) {
+      if (isNative()) return memCache[key] || null;
+      try { return localStorage.getItem(key); } catch(e) { return null; }
+    },
+
+    // Hydrate the memory cache from native storage at boot. Resolves when ready.
+    hydrate: function(keys) {
+      if (!isNative() || !plugin()) return Promise.resolve();
+      return Promise.all(keys.map(function(k) {
+        return plugin().get({ key: k })
+          .then(function(r) { memCache[k] = r.value; })
+          .catch(function() { memCache[k] = null; });
+      }));
+    }
+  };
+})();