diff --git a/backend/.idea/misc.xml b/backend/.idea/misc.xml
index 61a3499..02ee1de 100644
--- a/backend/.idea/misc.xml
+++ b/backend/.idea/misc.xml
@@ -1,4 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="Black">
+    <option name="sdkName" value="Python 3.11 (venv)" />
+  </component>
   <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.11 (venv)" project-jdk-type="Python SDK" />
 </project>
\ No newline at end of file
diff --git a/backend/authentication/models.py b/backend/authentication/models.py
index b89b561..5ef3890 100644
--- a/backend/authentication/models.py
+++ b/backend/authentication/models.py
@@ -25,6 +25,10 @@ class KnownIdentity(models.Model):
     def is_authenticated(self):
         return True
 
+    def friends_or_self(self):
+        return ToolshedUser.objects.filter(public_identity__friends=self) | ToolshedUser.objects.filter(
+            public_identity=self)
+
     def verify(self, message, signature):
         if len(signature) != 128 or type(signature) != str:
             raise TypeError('Signature must be 128 characters long and a string')
@@ -53,7 +57,8 @@ class ToolshedUserManager(auth.models.BaseUserManager):
         try:
             with transaction.atomic():
                 extra_fields['public_identity'] = identity = KnownIdentity.objects.get_or_create(
-                    username=username, domain=domain, public_key=public_key.encode(encoder=HexEncoder).decode('utf-8'))[0]
+                    username=username, domain=domain,
+                    public_key=public_key.encode(encoder=HexEncoder).decode('utf-8'))[0]
                 try:
                     with transaction.atomic():
                         user = super().create(username=username, email=email, password=password, domain=domain,
diff --git a/backend/files/media_urls.py b/backend/files/media_urls.py
index ec2c24e..aca590d 100644
--- a/backend/files/media_urls.py
+++ b/backend/files/media_urls.py
@@ -2,22 +2,27 @@ from django.http import HttpResponse
 from django.urls import path
 from drf_yasg.utils import swagger_auto_schema
 from rest_framework import status
-from rest_framework.decorators import api_view
+from rest_framework.decorators import api_view, permission_classes, authentication_classes
+from rest_framework.permissions import IsAuthenticated
 from rest_framework.response import Response
 
+from authentication.signature_auth import SignatureAuthentication
 from files.models import File
 
 
-# TODO check file permissions here
 @swagger_auto_schema(method='GET', auto_schema=None)
 @api_view(['GET'])
-def media_urls(request, id, format=None):
+@permission_classes([IsAuthenticated])
+@authentication_classes([SignatureAuthentication])
+def media_urls(request, hash_path):
     try:
-        file = File.objects.get(file=id)
+        file = File.objects.filter(connected_items__owner__in=request.user.friends_or_self()).distinct().get(
+            file=hash_path)
+
         return HttpResponse(status=status.HTTP_200_OK,
                             content_type=file.mime_type,
                             headers={
-                                'X-Accel-Redirect': f'/redirect_media/{id}',
+                                'X-Accel-Redirect': f'/redirect_media/{hash_path}',
                                 'Access-Control-Allow-Origin': '*',
                             })  # TODO Expires and Cache-Control
 
@@ -26,5 +31,5 @@ def media_urls(request, id, format=None):
 
 
 urlpatterns = [
-    path('<path:id>', media_urls),
+    path('<path:hash_path>', media_urls),
 ]
diff --git a/backend/files/tests.py b/backend/files/tests.py
index a9dc525..40f6413 100644
--- a/backend/files/tests.py
+++ b/backend/files/tests.py
@@ -3,6 +3,7 @@ from django.core.files.storage import DefaultStorage
 from django.db import IntegrityError, transaction
 from django.test import Client
 from authentication.tests import SignatureAuthClient, ToolshedTestCase, UserTestMixin
+from toolshed.tests import InventoryTestMixin
 from nacl.hash import sha256
 from nacl.encoding import HexEncoder
 import base64
@@ -105,11 +106,19 @@ class FilesTestCase(FilesTestMixin, ToolshedTestCase):
         self.assertEqual(countdir(DefaultStorage(), ''), 3)
 
 
-class MediaUrlTestCase(FilesTestMixin, UserTestMixin, ToolshedTestCase):
+class MediaUrlTestCase(FilesTestMixin, UserTestMixin, InventoryTestMixin, ToolshedTestCase):
     def setUp(self):
         super().setUp()
         self.prepare_files()
         self.prepare_users()
+        self.prepare_categories()
+        self.prepare_tags()
+        self.prepare_properties()
+        self.prepare_inventory()
+        self.f['item1'].files.add(self.f['test_file1'])
+        self.f['item1'].files.add(self.f['test_file2'])
+        self.f['item2'].files.add(self.f['test_file1'])
+
 
     def test_file_url(self):
         reply = client.get(
@@ -126,10 +135,33 @@ class MediaUrlTestCase(FilesTestMixin, UserTestMixin, ToolshedTestCase):
         self.assertEqual(reply.headers['X-Accel-Redirect'],
                          f"/redirect_media/{self.f['hash2'][:2]}/{self.f['hash2'][2:4]}/{self.f['hash2'][4:6]}/{self.f['hash2'][6:]}")
         self.assertEqual(reply.headers['Content-Type'], self.f['test_file2'].mime_type)
+        reply = client.get(
+            f"/media/{self.f['hash2'][:2]}/{self.f['hash2'][2:4]}/{self.f['hash2'][4:6]}/{self.f['hash2'][6:]}",
+            self.f['local_user2'])
+        self.assertEqual(reply.status_code, 200)
+        self.assertEqual(reply.headers['X-Accel-Redirect'],
+                         f"/redirect_media/{self.f['hash2'][:2]}/{self.f['hash2'][2:4]}/{self.f['hash2'][4:6]}/{self.f['hash2'][6:]}")
+        self.assertEqual(reply.headers['Content-Type'], self.f['test_file2'].mime_type)
 
     def test_file_url_fail(self):
         reply = client.get('/media/{}/'.format('nonexistent'), self.f['local_user1'])
         self.assertEqual(reply.status_code, 404)
         self.assertTrue('X-Accel-Redirect' not in reply.headers)
 
+    def test_file_url_anonymous(self):
+        reply = anonymous_client.get(
+            f"/media/{self.f['hash1'][:2]}/{self.f['hash1'][2:4]}/{self.f['hash1'][4:6]}/{self.f['hash1'][6:]}")
+        self.assertEqual(reply.status_code, 403)
+        self.assertTrue('X-Accel-Redirect' not in reply.headers)
 
+    def test_file_url_wrong_user(self):
+        reply = client.get(
+            f"/media/{self.f['hash3'][:2]}/{self.f['hash3'][2:4]}/{self.f['hash3'][4:6]}/{self.f['hash3'][6:]}",
+            self.f['local_user1'])
+        self.assertEqual(reply.status_code, 404)
+        self.assertTrue('X-Accel-Redirect' not in reply.headers)
+        reply = client.get(
+            f"/media/{self.f['hash2'][:2]}/{self.f['hash2'][2:4]}/{self.f['hash2'][4:6]}/{self.f['hash2'][6:]}",
+            self.f['ext_user1'])
+        self.assertEqual(reply.status_code, 404)
+        self.assertTrue('X-Accel-Redirect' not in reply.headers)
diff --git a/backend/toolshed/api/info.py b/backend/toolshed/api/info.py
index bb0124c..1ed623d 100644
--- a/backend/toolshed/api/info.py
+++ b/backend/toolshed/api/info.py
@@ -64,8 +64,7 @@ def combined_info(request, format=None):  # /info/
     categories = [str(category) for category in Category.objects.all()]
     policies = ['private', 'friends', 'internal', 'public']
     domains = [domain.name for domain in Domain.objects.filter(open_registration=True)]
-    return Response(
-        {'tags': tags, 'properties': properties, 'policies': policies, 'categories': categories, 'domains': domains})
+    return Response({'tags': tags, 'properties': properties, 'availability_policies': policies, 'categories': categories, 'domains': domains})
 
 
 urlpatterns = [
diff --git a/backend/toolshed/tests/test_api.py b/backend/toolshed/tests/test_api.py
index 8a79370..18968d7 100644
--- a/backend/toolshed/tests/test_api.py
+++ b/backend/toolshed/tests/test_api.py
@@ -52,10 +52,9 @@ class CombinedApiTestCase(UserTestMixin, CategoryTestMixin, TagTestMixin, Proper
     def test_combined_api(self):
         response = client.get('/api/info/', self.f['local_user1'])
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json()['policies'], ['private', 'friends', 'internal', 'public'])
+        self.assertEqual(response.json()['availability_policies'], ['private', 'friends', 'internal', 'public'])
         self.assertEqual(response.json()['categories'],
                          ['cat1', 'cat2', 'cat3', 'cat1/subcat1', 'cat1/subcat2', 'cat1/subcat1/subcat3'])
         self.assertEqual(response.json()['tags'], ['tag1', 'tag2', 'tag3'])
         self.assertEqual([p['name'] for p in response.json()['properties']], ['prop1', 'prop2', 'prop3'])
         self.assertEqual(response.json()['domains'], ['example.com'])
-        self.assertEqual(response.json()['policies'], ['private', 'friends', 'internal', 'public'])
diff --git a/backend/toolshed/tests/test_inventory.py b/backend/toolshed/tests/test_inventory.py
index d71e6a2..747c19e 100644
--- a/backend/toolshed/tests/test_inventory.py
+++ b/backend/toolshed/tests/test_inventory.py
@@ -1,7 +1,7 @@
 from authentication.tests import SignatureAuthClient, UserTestMixin, ToolshedTestCase
 from files.tests import FilesTestMixin
 from toolshed.models import InventoryItem, Category
-from toolshed.tests import InventoryTestMixin, CategoryTestMixin, TagTestMixin, PropertyTestMixin
+from toolshed.tests import InventoryTestMixin
 
 client = SignatureAuthClient()