diff --git a/spec/Protocol_Interface_PeerSecurity.xml b/spec/Protocol_Interface_PeerSecurity.xml
new file mode 100644
index 0000000..607b6e5
--- /dev/null
+++ b/spec/Protocol_Interface_PeerSecurity.xml
@@ -0,0 +1,92 @@
+<?xml version="1.0" ?>
+<node name="/Protocol_Interface_PeerSecurity"
+  xmlns:tp="http://telepathy.freedesktop.org/wiki/DbusSpec#extensions-v0">
+
+  <tp:copyright>Copyright © 2011 Collabora Ltd.</tp:copyright>
+  <tp:license xmlns="http://www.w3.org/1999/xhtml">
+    <p>This library is free software; you can redistribute it and/or
+      modify it under the terms of the GNU Lesser General Public
+      License as published by the Free Software Foundation; either
+      version 2.1 of the License, or (at your option) any later version.</p>
+
+    <p>This library is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+      Lesser General Public License for more details.</p>
+
+    <p>You should have received a copy of the GNU Lesser General Public
+      License along with this library; if not, write to the Free Software
+      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+      02110-1301, USA.</p>
+  </tp:license>
+
+  <interface name="org.freedesktop.Telepathy.Protocol.Interface.PeerSecurity">
+    <tp:added version="0.21.5">(as stable API)</tp:added>
+    <tp:requires interface="org.freedesktop.Telepathy.Protocol"/>
+
+    <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
+      <p>An interface to examine the security properties of a peers or servers
+	that can be connected to via this protocol.</p>
+    </tp:docstring>
+
+    <method name="RetrieveCertificates"
+      tp:name-for-bindings="Retrieve_Certificates">
+      <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
+        <p>Make a request to retrieve the TLS certificates that can be used to
+          authenticate a peer an establish security.</p>
+      </tp:docstring>
+
+      <arg direction="in" name="Parameters"
+        type="a{sv}" tp:type="String_Variant_Map">
+        <tp:docstring>
+          A set of parameters as would be provided to <tp:dbus-ref
+            namespace="org.freedesktop.Telepathy.ConnectionManager"
+            >RequestConnection</tp:dbus-ref>. Only parameters relevant to
+            connecting to a peer will be use to perform this operation.
+        </tp:docstring>
+      </arg>
+
+      <arg direction="out" name="Retrieve_Identifier" type="s">
+        <tp:docstring>
+          <p>An opaque string which identifies this retrieve request.
+            The same string will be used in the
+            <tp:dbus-ref
+            namespace="org.freedesktop.Telepathy.Protocol.Interface.PeerSecurity"
+            >RetrievedCertificates</tp:dbus-ref> signal.</p>
+        </tp:docstring>
+      </arg>
+    </method>
+
+    <signal name="RetrievedCertificates"
+        tp:name-for-bindings="Retrieved_Certificates">
+      <arg name="Retrieve_Identifier" type="s">
+        <tp:docstring>
+          The opaque string returned from
+          <tp:dbus-ref
+          namespace="org.freedesktop.Telepathy.Protocol.Interface.PeerSecurity"
+          >RetrieveCertificates</tp:dbus-ref>.
+        </tp:docstring>
+      </arg>
+      <arg name="CertificateType" type="s">
+        <tp:docstring>
+          The type of the certificate. Either 'x509', 'pgp' or '' when no
+          certificates were found.
+        </tp:docstring>
+      </arg>
+      <arg name="Certificates" type="aay">
+        <tp:docstring>
+          The certificates retrieved. When CertificateType is 'x509' this
+          represents a certificate chain the first of which is the peer's own
+          certificate. If an empty array, then no certificates were retrieved.
+        </tp:docstring>
+      </arg>
+      <tp:docstring>
+        Emitted when the results of a
+        <tp:dbus-ref
+        namespace="org.freedesktop.Telepathy.Protocol.Interface.PeerSecurity"
+        >RetrieveCertificates</tp:dbus-ref> are ready.
+      </tp:docstring>
+    </signal>
+
+  </interface>
+</node>
diff --git a/spec/all.xml b/spec/all.xml
index 63353c5..26df8cf 100644
--- a/spec/all.xml
+++ b/spec/all.xml
@@ -36,6 +36,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.</
  <xi:include href="Protocol.xml"/>
  <xi:include href="Protocol_Interface_Addressing.xml"/>
  <xi:include href="Protocol_Interface_Avatars.xml"/>
+ <xi:include href="Protocol_Interface_PeerSecurity.xml"/>
  <xi:include href="Protocol_Interface_Presence.xml"/>
 
  <tp:section name="Connection Object">