diff --git a/lib/cartodb/controllers/layergroup.js b/lib/cartodb/controllers/layergroup.js
index 9644aa06..f787c426 100644
--- a/lib/cartodb/controllers/layergroup.js
+++ b/lib/cartodb/controllers/layergroup.js
@@ -6,6 +6,7 @@ var BaseController = require('./base');
 
 var cors = require('../middleware/cors');
 var userMiddleware = require('../middleware/user');
+var layergroupTokenMiddleware = require('../middleware/layergroup-token');
 var allowQueryParams = require('../middleware/allow-query-params');
 
 var DataviewBackend = require('../backends/dataview');
@@ -52,29 +53,31 @@ module.exports = LayergroupController;
 
 LayergroupController.prototype.register = function(app) {
     app.get(app.base_url_mapconfig +
-        '/:token/:z/:x/:y@:scale_factor?x.:format', cors(), userMiddleware,
+        '/:token/:z/:x/:y@:scale_factor?x.:format', cors(), userMiddleware, layergroupTokenMiddleware,
         this.tile.bind(this));
 
     app.get(app.base_url_mapconfig +
-        '/:token/:z/:x/:y.:format', cors(), userMiddleware,
+        '/:token/:z/:x/:y.:format', cors(), userMiddleware, layergroupTokenMiddleware,
         this.tile.bind(this));
 
     app.get(app.base_url_mapconfig +
-        '/:token/:layer/:z/:x/:y.(:format)', cors(), userMiddleware,
+        '/:token/:layer/:z/:x/:y.(:format)', cors(), userMiddleware, layergroupTokenMiddleware,
         this.layer.bind(this));
 
     app.get(app.base_url_mapconfig +
-        '/:token/:layer/attributes/:fid', cors(), userMiddleware,
+        '/:token/:layer/attributes/:fid', cors(), userMiddleware, layergroupTokenMiddleware,
         this.attributes.bind(this));
 
     app.get(app.base_url_mapconfig +
         '/static/center/:token/:z/:lat/:lng/:width/:height.:format',
         cors(), userMiddleware, allowQueryParams(['layer']),
+        layergroupTokenMiddleware,
         this.center.bind(this));
 
     app.get(app.base_url_mapconfig +
         '/static/bbox/:token/:west,:south,:east,:north/:width/:height.:format',
         cors(), userMiddleware, allowQueryParams(['layer']),
+        layergroupTokenMiddleware,
         this.bbox.bind(this));
 
     // Undocumented/non-supported API endpoint methods.
@@ -98,6 +101,7 @@ LayergroupController.prototype.register = function(app) {
         cors(),
         userMiddleware,
         allowQueryParams(allowedDataviewQueryParams),
+        layergroupTokenMiddleware,
         this.dataview.bind(this)
     );
 
@@ -106,6 +110,7 @@ LayergroupController.prototype.register = function(app) {
         cors(),
         userMiddleware,
         allowQueryParams(allowedDataviewQueryParams),
+        layergroupTokenMiddleware,
         this.dataview.bind(this)
     );
 
@@ -114,6 +119,7 @@ LayergroupController.prototype.register = function(app) {
         cors(),
         userMiddleware,
         allowQueryParams(allowedDataviewQueryParams),
+        layergroupTokenMiddleware,
         this.dataviewSearch.bind(this)
     );
 
@@ -122,11 +128,13 @@ LayergroupController.prototype.register = function(app) {
         cors(),
         userMiddleware,
         allowQueryParams(allowedDataviewQueryParams),
+        layergroupTokenMiddleware,
         this.dataviewSearch.bind(this)
     );
 
     app.get(app.base_url_mapconfig +
         '/:token/analysis/node/:nodeId', cors(), userMiddleware,
+        layergroupTokenMiddleware,
         this.analysisNodeStatus.bind(this));
 };
 
diff --git a/lib/cartodb/middleware/layergroup-token.js b/lib/cartodb/middleware/layergroup-token.js
new file mode 100644
index 00000000..d9f7d214
--- /dev/null
+++ b/lib/cartodb/middleware/layergroup-token.js
@@ -0,0 +1,35 @@
+var LayergroupToken = require('../models/layergroup-token');
+
+module.exports = function layergroupTokenMiddleware(req, res, next) {
+    if (!req.params.hasOwnProperty('token')) {
+        return next();
+    }
+
+    var user = req.context.user;
+
+    var layergroupToken = LayergroupToken.parse(req.params.token);
+    req.params.token = layergroupToken.token;
+    req.params.cache_buster = layergroupToken.cacheBuster;
+
+    if (layergroupToken.signer) {
+        req.params.signer = layergroupToken.signer;
+        if (!req.params.signer) {
+            req.params.signer = user;
+        } else if (req.params.signer !== user) {
+            var statusCode = 403;
+            if (req.query && req.query.callback) {
+                statusCode = 200;
+            }
+            var errorMessage = `Cannot use map signature of user "${req.params.signer}" on db of user "{${user}"`;
+            return res.status(statusCode).json({
+                errors: [errorMessage],
+                errors_with_context: [{
+                    type: 'auth',
+                    message: errorMessage
+                }]
+            });
+        }
+    }
+
+    return next();
+};
diff --git a/test/acceptance/ported/support/ported_server_options.js b/test/acceptance/ported/support/ported_server_options.js
index d9af2d91..a2302288 100644
--- a/test/acceptance/ported/support/ported_server_options.js
+++ b/test/acceptance/ported/support/ported_server_options.js
@@ -1,6 +1,5 @@
 var _ = require('underscore');
 var serverOptions = require('../../../../lib/cartodb/server_options');
-var LayergroupToken = require('../../../../lib/cartodb/models/layergroup-token');
 var mapnik = require('windshaft').mapnik;
 var OverviewsQueryRewriter = require('../../../../lib/cartodb/utils/overviews_query_rewriter');
 var overviewsQueryRewriter = new OverviewsQueryRewriter({
@@ -56,9 +55,12 @@ module.exports = _.extend({}, serverOptions, {
 
         // this is in case you want to test sql parameters eg ...png?sql=select * from my_table limit 10
         req.params =  _.extend({}, req.params);
-        if (req.params.token) {
-            req.params.token = LayergroupToken.parse(req.params.token).token;
-        }
+
+        // We don't want to inherit Date.now() `cache_buster` as it is the default value
+        // introduced by the middleware when no cache buster is found.
+        // We are only interested in the `token` for the ported tests.
+        delete req.params.cache_buster;
+        delete req.params.signer;
 
         _.extend(req.params, req.query);
         req.params.user = 'localhost';