diff --git a/core/modules/new_widgets/encrypt.js b/core/modules/new_widgets/encrypt.js
new file mode 100644
index 000000000..777dcb89b
--- /dev/null
+++ b/core/modules/new_widgets/encrypt.js
@@ -0,0 +1,85 @@
+/*\
+title: $:/core/modules/new_widgets/encrypt.js
+type: application/javascript
+module-type: new_widget
+
+Encrypt widget
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+var Widget = require("$:/core/modules/new_widgets/widget.js").widget;
+
+var EncryptWidget = function(parseTreeNode,options) {
+	this.initialise(parseTreeNode,options);
+};
+
+/*
+Inherit from the base widget class
+*/
+EncryptWidget.prototype = new Widget();
+
+/*
+Render this widget into the DOM
+*/
+EncryptWidget.prototype.render = function(parent,nextSibling) {
+	this.parentDomNode = parent;
+	this.computeAttributes();
+	this.execute();
+	var textNode = this.document.createTextNode(this.encryptedText);
+	parent.insertBefore(textNode,nextSibling);
+	this.domNodes.push(textNode);
+};
+
+/*
+Compute the internal state of the widget
+*/
+EncryptWidget.prototype.execute = function() {
+	// Get parameters from our attributes
+	this.filter = this.getAttribute("filter","[!is[system]]");
+	// Encrypt the filtered tiddlers
+	var tiddlers = this.wiki.filterTiddlers(this.filter),
+		json = {},
+		self = this;
+	$tw.utils.each(tiddlers,function(title) {
+		var tiddler = self.wiki.getTiddler(title),
+			jsonTiddler = {};
+		for(var f in tiddler.fields) {
+			jsonTiddler[f] = tiddler.getFieldString(f);
+		}
+		json[title] = jsonTiddler;
+	});
+	this.encryptedText = $tw.utils.htmlEncode($tw.crypto.encrypt(JSON.stringify(json)));
+};
+
+/*
+Selectively refreshes the widget if needed. Returns true if the widget or any of its children needed re-rendering
+*/
+EncryptWidget.prototype.refresh = function(changedTiddlers) {
+	var changedAttributes = this.computeAttributes(),
+		affectedTiddlers = this.wiki.filterTiddlers(this.filter,null,changedTiddlers);
+	if(changedAttributes.filter || affectedTiddlers.length > 0) {
+		this.refreshSelf();
+		return true;
+	} else {
+		return false;	
+	}
+};
+
+/*
+Remove any DOM nodes created by this widget
+*/
+EncryptWidget.prototype.removeChildDomNodes = function() {
+	$tw.utils.each(this.domNodes,function(domNode) {
+		domNode.parentNode.removeChild(domNode);
+	});
+	this.domNodes = [];
+};
+
+exports.encrypt = EncryptWidget;
+
+})();
diff --git a/nbld.sh b/nbld.sh
index 52082a18f..2ee7e4e08 100755
--- a/nbld.sh
+++ b/nbld.sh
@@ -28,6 +28,15 @@ node ./tiddlywiki.js \
 	--new_rendertiddlers [!is[system]] $:/core/templates/static.tiddler.html $TW5_BUILD_OUTPUT/static text/plain \
 	|| exit 1
 
+# Second, encrypted.html: a version of the main file encrypted with the password "password"
+
+node ./tiddlywiki.js \
+	./editions/tw5.com \
+	--verbose \
+	--password password \
+	--new_rendertiddler $:/core/templates/tiddlywiki5.template.html $TW5_BUILD_OUTPUT/encrypted.html text/plain \
+	|| exit 1
+
 # Run tests
 
 ./test.sh