diff --git a/django_netjsonconfig/migrations/0001_initial.py b/django_netjsonconfig/migrations/0001_initial.py
index 1310aba..2745b99 100644
--- a/django_netjsonconfig/migrations/0001_initial.py
+++ b/django_netjsonconfig/migrations/0001_initial.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-# Generated by Django 1.9c1 on 2015-12-01 18:00
+# Generated by Django 1.9 on 2015-12-14 15:01
 from __future__ import unicode_literals
 
 from django.db import migrations, models
@@ -27,6 +27,7 @@ class Migration(migrations.Migration):
                 ('name', models.CharField(max_length=63)),
                 ('backend', models.CharField(choices=[('netjsonconfig.OpenWrt', 'OpenWRT'), ('netjsonconfig.OpenWisp', 'OpenWISP')], help_text='Select netjsonconfig backend', max_length=128, verbose_name='backend')),
                 ('config', jsonfield.fields.JSONField(default=dict, help_text='configuration in NetJSON DeviceConfiguration format', verbose_name='configuration')),
+                ('key', models.CharField(db_index=True, help_text='unique key that will be used to build the download URL', max_length=64, unique=True)),
             ],
             options={
                 'abstract': False,
diff --git a/django_netjsonconfig/models/device.py b/django_netjsonconfig/models/device.py
index 8c68329..1daa704 100644
--- a/django_netjsonconfig/models/device.py
+++ b/django_netjsonconfig/models/device.py
@@ -97,6 +97,10 @@ class BaseDevice(AbstractConfig):
     Abstract model implementing the
     NetJSON DeviceConfiguration object
     """
+    key = models.CharField(max_length=64, unique=True, db_index=True,
+                           help_text=_('unique key that will be used to '
+                                       'build the download URL'))
+
     class Meta:
         abstract = True
 
diff --git a/django_netjsonconfig/tests/test_device.py b/django_netjsonconfig/tests/test_device.py
index a55e426..3596ab7 100644
--- a/django_netjsonconfig/tests/test_device.py
+++ b/django_netjsonconfig/tests/test_device.py
@@ -14,6 +14,7 @@ class TestDevice(TestCase):
     """
     fixtures = ['test_templates']
     maxDiff = None
+    TEST_KEY = '00:11:22:33:44:55'
 
     def test_str(self):
         d = Device(name='test')
@@ -30,7 +31,10 @@ def test_backend_instance(self):
 
     def test_validation(self):
         config = {'interfaces': {'invalid': True}}
-        d = Device(name='test', backend='netjsonconfig.OpenWrt', config=config)
+        d = Device(name='test',
+                   backend='netjsonconfig.OpenWrt',
+                   config=config,
+                   key=self.TEST_KEY)
         # ensure django ValidationError is raised
         with self.assertRaises(ValidationError):
             d.full_clean()
@@ -40,7 +44,8 @@ def test_json(self):
         radio = Template.objects.get(name='radio0')
         d = Device(name='test',
                    backend='netjsonconfig.OpenWrt',
-                   config={'general':{'hostname':'json-test'}})
+                   config={'general':{'hostname':'json-test'}},
+                   key=self.TEST_KEY)
         d.full_clean()
         d.save()
         d.templates.add(dhcp)
@@ -99,7 +104,7 @@ def test_m2m_validation(self):
         t = Template(name='files', **kwargs)
         t.full_clean()
         t.save()
-        d = Device(name='test', **kwargs)
+        d = Device(name='test', key=self.TEST_KEY, **kwargs)
         d.full_clean()
         d.save()
         with atomic():
diff --git a/django_netjsonconfig/tests/test_device_admin.py b/django_netjsonconfig/tests/test_device_admin.py
index 31f15be..ec6ba8d 100644
--- a/django_netjsonconfig/tests/test_device_admin.py
+++ b/django_netjsonconfig/tests/test_device_admin.py
@@ -10,27 +10,29 @@ class TestDeviceAdmin(TestCase):
     """
     fixtures = ['test_templates', 'test_users']
     maxDiff = None
+    TEST_KEY = '00:11:22:33:44:55'
 
     def setUp(self):
         self.client.login(username='admin', password='tester')
 
     def test_clean_templates(self):
         t = Template.objects.first()
-        d = Device(name='test', backend=t.backend, config=t.config)
+        d = Device(name='test', backend=t.backend, config=t.config, key=self.TEST_KEY)
         d.full_clean()
         d.save()
         path = reverse('admin:django_netjsonconfig_device_change', args=[d.pk])
         # ensure it fails with error
-        response = self.client.post(path, {'templates': str(t.pk)})
+        response = self.client.post(path, {'templates': str(t.pk), 'key': self.TEST_KEY})
         self.assertIn('errors field-templates', str(response.content))
         # remove conflicting template and ensure doesn't error
-        response = self.client.post(path, {'templates': ''})
+        response = self.client.post(path, {'templates': '', 'key': self.TEST_KEY})
         self.assertNotIn('errors field-templates', str(response.content))
 
     def test_download_config(self):
         d = Device(name='download',
                    backend='netjsonconfig.OpenWrt',
-                   config={'general':{'hostname':'device'}})
+                   config={'general':{'hostname':'device'}},
+                   key=self.TEST_KEY)
         d.full_clean()
         d.save()
         path = reverse('admin:django_netjsonconfig_device_download', args=[d.pk])
@@ -40,7 +42,8 @@ def test_download_config(self):
     def test_visualize_config(self):
         d = Device(name='download',
                    backend='netjsonconfig.OpenWrt',
-                   config={'general':{'hostname':'device'}})
+                   config={'general':{'hostname':'device'}},
+                   key=self.TEST_KEY)
         d.full_clean()
         d.save()
         path = reverse('admin:django_netjsonconfig_device_visualize', args=[d.pk])