diff --git a/lib/crypto/index.js b/lib/crypto/index.js
index 28b65ca91..a0cd4fc70 100644
--- a/lib/crypto/index.js
+++ b/lib/crypto/index.js
@@ -797,10 +797,15 @@ Crypto.prototype.encryptEventIfNeeded = function(event, room) {
         return null;
     }
 
+    var myKeys = {
+        curve25519: this._olmDevice.deviceCurve25519Key,
+        ed25519: this._olmDevice.deviceEd25519Key,
+    };
+
     return alg.encryptMessage(
         room, event.getType(), event.getContent()
     ).then(function(encryptedContent) {
-        event.makeEncrypted("m.room.encrypted", encryptedContent);
+        event.makeEncrypted("m.room.encrypted", encryptedContent, myKeys);
     });
 };
 
diff --git a/lib/models/event.js b/lib/models/event.js
index 83bf207c3..7f4e91259 100644
--- a/lib/models/event.js
+++ b/lib/models/event.js
@@ -214,12 +214,15 @@ module.exports.MatrixEvent.prototype = {
      * <tt>"m.room.encrypted"</tt>
      *
      * @param {object} crypto_content raw 'content' for the encrypted event.
+     * @param {object} keys The local keys claimed and proved by this event.
      */
-    makeEncrypted: function(crypto_type, crypto_content) {
+    makeEncrypted: function(crypto_type, crypto_content, keys) {
         // keep the plain-text data for 'view source'
         this._clearEvent = {
             type: this.event.type,
             content: this.event.content,
+            keysProved: keys,
+            keysClaimed: keys,
         };
         this.event.type = crypto_type;
         this.event.content = crypto_content;
@@ -243,6 +246,10 @@ module.exports.MatrixEvent.prototype = {
 
     /**
      * The keys that must have been owned by the sender of this encrypted event.
+     * These don't necessarily have to come from this event itself, but may be
+     * implied by the cryptographic session.
+     * For example megolm messages don't claim keys directly, but instead
+     * inherit a claim from the olm message that established the session.
      * @return {object}
      */
     getKeysProved: function() {
@@ -251,6 +258,10 @@ module.exports.MatrixEvent.prototype = {
 
     /**
      * The additional keys the sender of this encrypted event claims to possess
+     * These don't necessarily have to come from this event itself, but may be
+     * implied by the cryptographic session.
+     * For example megolm messages don't claim keys directly, but instead
+     * inherit a claim from the olm message that established the session.
      * @return {object}
      */
     getKeysClaimed: function() {