diff --git a/ceilometer/collector/manager.py b/ceilometer/collector/manager.py
index 7a435040..33b15a75 100644
--- a/ceilometer/collector/manager.py
+++ b/ceilometer/collector/manager.py
@@ -23,6 +23,7 @@ from nova.rpc import dispatcher as rpc_dispatcher
 
 from ceilometer import cfg
 from ceilometer import log
+from ceilometer import meter
 from ceilometer import publish
 from ceilometer import rpc
 from ceilometer.collector import dispatcher
@@ -84,8 +85,11 @@ class CollectorManager(manager.Manager):
                  data['event_type'],
                  data['resource_id'],
                  data['counter_volume'])
-        try:
-            self.storage_conn.record_metering_data(data)
-        except Exception as err:
-            LOG.error('Failed to record metering data: %s', err)
-            LOG.exception(err)
+        if not meter.verify_signature(data):
+            LOG.warning('message signature invalid, discarding message')
+        else:
+            try:
+                self.storage_conn.record_metering_data(data)
+            except Exception as err:
+                LOG.error('Failed to record metering data: %s', err)
+                LOG.exception(err)
diff --git a/ceilometer/meter.py b/ceilometer/meter.py
index 802704f9..1e4471f8 100644
--- a/ceilometer/meter.py
+++ b/ceilometer/meter.py
@@ -52,6 +52,15 @@ def compute_signature(message):
     return digest_maker.hexdigest()
 
 
+def verify_signature(message):
+    """Check the signature in the message against the value computed
+    from the rest of the contents.
+    """
+    old_sig = message.get('message_signature')
+    new_sig = compute_signature(message)
+    return new_sig == old_sig
+
+
 def meter_message_from_counter(counter):
     """Make a metering message ready to be published or stored.
 
diff --git a/tests/collector/test_manager.py b/tests/collector/test_manager.py
new file mode 100644
index 00000000..317990c1
--- /dev/null
+++ b/tests/collector/test_manager.py
@@ -0,0 +1,71 @@
+# -*- encoding: utf-8 -*-
+#
+# Copyright © 2012 New Dream Network, LLC (DreamHost)
+#
+# Author: Doug Hellmann <doug.hellmann@dreamhost.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+"""Tests for ceilometer/agent/manager.py
+"""
+
+import datetime
+
+from nova import context
+from nova import test
+
+from ceilometer import meter
+from ceilometer.collector import manager
+from ceilometer.storage import base
+
+
+class TestCollectorManager(test.TestCase):
+
+    def setUp(self):
+        super(TestCollectorManager, self).setUp()
+        self.mgr = manager.CollectorManager()
+        self.ctx = context.RequestContext("user", "project")
+
+    def test_valid_message(self):
+        msg = {'event_type': 'test',
+               'resource_id': self.id(),
+               'counter_volume': 1,
+               }
+        msg['message_signature'] = meter.compute_signature(msg)
+
+        self.mgr.storage_conn = self.mox.CreateMock(base.Connection)
+        self.mgr.storage_conn.record_metering_data(msg)
+        self.mox.ReplayAll()
+
+        self.mgr.record_metering_data(self.ctx, msg)
+        self.mox.VerifyAll()
+
+    def test_invalid_message(self):
+        msg = {'event_type': 'test',
+               'resource_id': self.id(),
+               'counter_volume': 1,
+               }
+        msg['message_signature'] = 'invalid-signature'
+
+        class ErrorConnection:
+
+            called = False
+
+            def record_metering_data(self, data):
+                self.called = True
+
+        self.mgr.storage_conn = ErrorConnection()
+
+        self.mgr.record_metering_data(self.ctx, msg)
+
+        assert not self.mgr.storage_conn.called, \
+            'Should not have called the storage connection'
diff --git a/tests/storage/test_register_opts.py b/tests/storage/test_register_opts.py
index 8998cfdd..71518e5e 100644
--- a/tests/storage/test_register_opts.py
+++ b/tests/storage/test_register_opts.py
@@ -44,3 +44,4 @@ class RegisterOpts(test.TestCase):
         self._faux_engine.register_opts(flags.FLAGS)
         self.mox.ReplayAll()
         storage.register_opts(flags.FLAGS)
+        self.mox.VerifyAll()
diff --git a/tests/test_meter.py b/tests/test_meter.py
index fc431eed..ef921cf4 100644
--- a/tests/test_meter.py
+++ b/tests/test_meter.py
@@ -61,6 +61,24 @@ def test_compute_signature_use_configured_secret():
     assert sig1 != sig2
 
 
+def test_verify_signature_signed():
+    data = {'a': 'A', 'b': 'B'}
+    sig1 = meter.compute_signature(data)
+    data['message_signature'] = sig1
+    assert meter.verify_signature(data)
+
+
+def test_verify_signature_unsigned():
+    data = {'a': 'A', 'b': 'B'}
+    assert not meter.verify_signature(data)
+
+
+def test_verify_signature_incorrect():
+    data = {'a': 'A', 'b': 'B',
+            'message_signature': 'Not the same'}
+    assert not meter.verify_signature(data)
+
+
 TEST_COUNTER = counter.Counter(source='src',
                                name='name',
                                type='typ',
diff --git a/tox.ini b/tox.ini
index c1dc90c6..d5848441 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,6 +13,9 @@ deps = -r{toxinidir}/tools/pip-requires
 commands = {toxinidir}/run_tests.sh
 sitepackages = True
 
+[testenv:py27]
+commands = {toxinidir}/run_tests.sh --with-coverage --cover-erase --cover-package=ceilometer --cover-inclusive
+
 [testenv:pep8]
 deps = pep8
 commands = pep8 --repeat --show-source ceilometer setup.py bin/ceilometer-agent bin/ceilometer-collector