diff --git a/sigal/plugins/encrypt/static/decrypt.js b/sigal/plugins/encrypt/static/decrypt.js
index b50af10..e640c44 100644
--- a/sigal/plugins/encrypt/static/decrypt.js
+++ b/sigal/plugins/encrypt/static/decrypt.js
@@ -30,15 +30,16 @@ class Decryptor {
         if (Decryptor.isServiceWorker()) {
             this._role = "service_worker";
         } else if (!Decryptor.isWorker()) {
-            if (!Decryptor.featureTest()) {
-                alert("This page cannot function properly because your browser does not support some critical features or you are in private browsing mode. Please update your browser or exit private browsing mode.");
-                return;
-            }
             this._role = "main";
             this._config = config;
             document.addEventListener(
                 "DOMContentLoaded",
                 (e) => {
+                    if (!Decryptor.featureTest()) {
+                        Decryptor.mSetUIVisibility("main-prompt", true);
+                        Decryptor.mSetUIVisibility("missing-feature", true);
+                        return;
+                    }
                     const local_config = this._mGetLocalConfig();
                     if (local_config) {
                         this._config = local_config;
@@ -53,11 +54,7 @@ class Decryptor {
     }
 
     static init(config) {
-        if (Decryptor.isServiceWorker()) {
-            self.decryptor = new Decryptor(config);
-        } else {
-            window.decryptor = new Decryptor(config);
-        }
+        self.decryptor = new Decryptor(config);
     }
 
     static featureTest() {
@@ -131,11 +128,11 @@ class Decryptor {
     }
 
     static isInitialized() {
-        if (Decryptor.isServiceWorker()) {
-            return 'decryptor' in self && self.decryptor.workerReady;
-        } else {
-            return 'decryptor' in window && window.decryptor.workerReady;
-        }
+        return 'decryptor' in self;
+    }
+
+    static isWorkerReady() {
+        return Decryptor.isInitialized() && self.decryptor._workerReady;
     }
 
     get workerReady() {
@@ -148,9 +145,12 @@ class Decryptor {
 
     _mSetWorkerReady() {
         this.workerReady = true;
-        const had_been_ready_before = this._mGetLocalConfig() !== null;
-        localStorage.setItem(this._config.galleryId, JSON.stringify(this._config));
-        if (!had_been_ready_before) {
+        Decryptor.mSetUIVisibility("main-prompt", false);
+        Decryptor.mSetUIVisibility("password-prompt", false);
+        Decryptor.mSetUIVisibility("incorrect-password", false);
+        const firstVisit = this._mGetLocalConfig() === null;
+        if (firstVisit) {
+            localStorage.setItem(this._config.galleryId, JSON.stringify(this._config));
             window.location.reload();
         }
     }
@@ -158,7 +158,10 @@ class Decryptor {
     _mUnsetWorkerReady() {
         this.workerReady = false;
         localStorage.removeItem(this._config.galleryId);
-        alert("Incorrect password!");
+        Decryptor.mSetUIVisibility("main-prompt", true);
+        Decryptor.mSetUIVisibility("password-prompt", true);
+        Decryptor.mSetUIVisibility("incorrect-password", true);
+        Decryptor.mPlayUIAnimation("incorrect-password");
     }
 
     _mGetLocalConfig() {
@@ -197,11 +200,28 @@ class Decryptor {
             (e) => Decryptor.onMessage(this.serviceWorker, e);
         this.serviceWorker = this._proxyWrap(this.serviceWorker);
 
-        if (!(await this.serviceWorker.Decryptor.isInitialized())) {
-            if (!('password' in this._config && this._config.password)) {
-                this._config.password = await this._mAskPassword();
+        if (!(await this.serviceWorker.Decryptor.isWorkerReady())) {
+            if ('password' in this._config && this._config.password) {
+                this.serviceWorker._swInitServiceWorker(this._config);
+            } else {
+                Decryptor.mSetUIVisibility("main-prompt", true);
+                Decryptor.mSetUIVisibility("password-prompt", true);
+                document.addEventListener(
+                    "DecryptorPasswordProvided",
+                    (e) => {
+                        const password = e.detail;
+                        if (password) {
+                            this._config.password = password;
+                            this.serviceWorker._swInitServiceWorker(this._config);
+                        }
+                    },
+                    { passive: true }
+                );
             }
-            this.serviceWorker._swInitServiceWorker(this._config);
+        } else {
+            this.workerReady = true;
+            Decryptor.mSetUIVisibility("main-prompt", false);
+            Decryptor.mSetUIVisibility("password-prompt", false);
         }
     }
 
@@ -221,18 +241,43 @@ class Decryptor {
         }
     }
 
-    /* main thread only */
-    async _mAskPassword() {
-        const config = this._mGetLocalConfig();
-        if (config && config.password) {
-            return config.password;
+    static async setPassword(password) {
+        Decryptor._sendEvent(document, "DecryptorPasswordProvided", password);
+    }
+
+    static mSetUIVisibility(UIElement, visible) {
+        let element;
+        switch (UIElement) {
+            case "password-prompt":
+                element = "decrypt-password-prompt";
+                break;
+            case "incorrect-password":
+                element = "indicator-text-incorrect-password";
+                break;
+            case "missing-feature":
+                element = "decrypt-missing-feature";
+                break;
+            case "main-prompt":
+                element = "decrypt-main-prompt";
+                break;
+            default:
+                return;
         }
-        const password = prompt("Input password to view this gallery:");
-        if (password) {
-            this._config.password = password;
-            return password;
+        if (visible) {
+            document.getElementById(element).classList.remove("hidden");
         } else {
-            return "__wrong_password__";
+            document.getElementById(element).classList.add("hidden");
+        }
+    }
+
+    static mPlayUIAnimation(UIElement) {
+        switch (UIElement) {
+            case "incorrect-password":
+                const element = document.getElementById("indicator-text-incorrect-password").parentElement;
+                element.classList.add("shake-animated");
+                break;
+            default:
+                return;
         }
     }
 
@@ -507,8 +552,8 @@ class Decryptor {
         }
         console.debug(`Fetch succeeded with encrypted image ${request.url}, trying to decrypt`);
 
-        if (!Decryptor.isInitialized()) {
-            if ('decryptor' in self) {
+        if (!Decryptor.isWorkerReady()) {
+            if (Decryptor.isInitialized()) {
                 try{
                     const client = await self.clients.get(e.clientId);
                     const config = await self.decryptor._proxyWrap(client)._mGetLocalConfig();
@@ -517,7 +562,7 @@ class Decryptor {
                     // do nothing
                 }
             }
-            if (!Decryptor.isInitialized()) {
+            if (!Decryptor.isWorkerReady()) {
                 console.debug(`Decryptor not initialized on fetch event`);
                 return Decryptor.imageErrorResponse.clone();
             }
diff --git a/sigal/themes/colorbox/templates/base.html b/sigal/themes/colorbox/templates/base.html
index 1836260..afa5338 100644
--- a/sigal/themes/colorbox/templates/base.html
+++ b/sigal/themes/colorbox/templates/base.html
@@ -13,7 +13,6 @@
     <link rel="stylesheet" href="{{ theme.url }}/css/style.css">
     {% block extra_head %}{% endblock extra_head %}
     {% include 'analytics.html' %}
-    {% include 'decrypt.html' %}
   </head>
   <body>
     {% include 'gtm.html' %}
@@ -50,5 +49,6 @@
     </div>
     {% block footer %}{% endblock %}
     {% include 'piwik.html' %}
+    {% include 'decrypt.html' %}
   </body>
 </html>
diff --git a/sigal/themes/default/templates/decrypt.html b/sigal/themes/default/templates/decrypt.html
index 0d7faf5..2cba418 100644
--- a/sigal/themes/default/templates/decrypt.html
+++ b/sigal/themes/default/templates/decrypt.html
@@ -1,13 +1,97 @@
-{% if 'sigal.plugins.encrypt' is in settings.plugins %}
-    <script src="{{ theme.url }}/decrypt.js"></script>
-    <script>
-        Decryptor.init({
-            password: "{{ encrypt_options.filtered_password }}",
-            sw_script: "{{ theme.url }}/../sw.js",
-            galleryId: "{{ encrypt_options.galleryId }}",
-            gcm_tag: "{{ encrypt_options.escaped_gcm_tag }}", 
-            kdf_salt: "{{ encrypt_options.escaped_kdf_salt }}", 
-            kdf_iters: {{ encrypt_options.kdf_iters }} 
-        });
-    </script>
+{% if 'sigal.plugins.encrypt' is in settings.plugins %}
+<script src="{{ theme.url }}/decrypt.js"></script>
+<script>
+    Decryptor.init({
+        password: "{{ encrypt_options.filtered_password }}",
+        sw_script: "{{ theme.url }}/../sw.js",
+        galleryId: "{{ encrypt_options.galleryId }}",
+        gcm_tag: "{{ encrypt_options.escaped_gcm_tag }}", 
+        kdf_salt: "{{ encrypt_options.escaped_kdf_salt }}", 
+        kdf_iters: {{ encrypt_options.kdf_iters }} 
+    });
+</script>
+<style>
+    .decrypt-fixed-prompt {
+        position: fixed;
+        top: 0; 
+        left: 0; 
+        width: 100vw; 
+        height: 100vh; 
+        background-color: inherit; 
+    }
+    .decrypt-prompt-panel {
+        width: 100%;
+        height: 100%;
+        display: flex;
+        flex-flow: column;
+        align-items: center;
+        justify-content: center;
+        text-align: center;
+    }
+    .decrypt-error-indicator {
+        color: red;
+        transform: translateX(0);
+    }
+    .hidden {
+        display: none !important;
+    }
+    .shake-animated {
+        animation: 0.1s ease-in-out 0s 2 normal shake;
+    }
+    @keyframes shake {
+        0% {transform: translateX(0px);}
+        25% {transform: translateX(-5px);}
+        50% {transform: translateX(0px);}
+        75% {transform: translateX(5px);}
+        100% {transform: translateX(0px);}
+    }
+    .close-marker {
+        position: absolute;
+        top: 2rem;
+        right: 2rem;
+        width: 2rem;
+        height: 2rem;
+        cursor: pointer;
+        background-color: inherit;
+    }
+    .close-marker-line {
+        width:2rem;
+        height: 2px;
+        background-color: inherit;
+        position: absolute; 
+        top: 1rem;
+        left: 0;
+        filter: invert(1);
+    }
+</style>
+<div class="decrypt-fixed-prompt hidden" id="decrypt-main-prompt">
+    <div id="decrypt-close-marker" class="close-marker" onclick="this.parentElement.classList.add('hidden')">
+        <div class="close-marker-line" style="transform: rotate(45deg);"></div>
+        <div class="close-marker-line" style="transform: rotate(-45deg);"></div>
+    </div>
+    <div class="decrypt-prompt-panel hidden" id="decrypt-password-prompt">
+        <h1>Private Gallery: {{ index_title }}</h1>
+        <p>Password is required to access this gallery:</p>
+        <form action="#" onsubmit="Decryptor.setPassword(document.getElementById('decrypt-password-input').value); return false;">
+            <input id="decrypt-password-input" placeholder="Password" type="text" />
+            <button id="decrypt-password-enter">Enter</button>
+        </form>
+        <p class="decrypt-error-indicator" onanimationend="this.classList.remove('shake-animated')">&nbsp;
+            <span class="hidden" id="indicator-text-incorrect-password">Incorrect password!</span>
+        </p>
+    </div>
+    <div class="decrypt-prompt-panel hidden"  id="decrypt-missing-feature">
+        <h1>Private Gallery: {{ index_title }}</h1>
+        <p>Password is required to access this gallery:</p>
+        <p class="decrypt-error-indicator">
+            This page cannot function properly because some features are not available.
+        </p>
+        <p>Some possible solutions are:</p>
+        <ul>
+            <li>You are in private browsing mode. Try switching to normal mode.</li>
+            <li>This page is not loaded from a HTTPS connection. Reload with HTTPS.</li>
+            <li>Your browser is outdated. Consider upgrading to a latest version.</li>
+        </ul>
+    </div>
+</div>
 {% endif %}
\ No newline at end of file
diff --git a/sigal/themes/galleria/templates/base.html b/sigal/themes/galleria/templates/base.html
index 6e96933..eb3ef9d 100644
--- a/sigal/themes/galleria/templates/base.html
+++ b/sigal/themes/galleria/templates/base.html
@@ -14,7 +14,6 @@
     <link rel="stylesheet" href="{{ theme.url }}/css/style.css">
     {% block extra_head %}{% endblock extra_head %}
     {% include 'analytics.html' %}
-    {% include 'decrypt.html' %}
   </head>
   <body>
     {% include 'gtm.html' %}
@@ -36,5 +35,6 @@
     </div>
     {% block late_js %}{% endblock late_js %}
     {% include 'piwik.html' %}
+    {% include 'decrypt.html' %}
   </body>
 </html>
diff --git a/sigal/themes/photoswipe/templates/base.html b/sigal/themes/photoswipe/templates/base.html
index 70b4f88..dec1b40 100644
--- a/sigal/themes/photoswipe/templates/base.html
+++ b/sigal/themes/photoswipe/templates/base.html
@@ -11,7 +11,6 @@
     {% block extra_head %}{% endblock extra_head %}
     <link rel="stylesheet" href="{{ theme.url }}/styles.css">
     {% include 'analytics.html' %}
-    {% include 'decrypt.html' %}
   </head>
   <body>
     {% include 'gtm.html' %}
@@ -35,5 +34,6 @@
       {% block extra_footer %}{% endblock %}
   </div>
   {% include 'piwik.html' %}
+  {% include 'decrypt.html' %}
   </body>
 </html>