diff --git a/lib/OlmDevice.js b/lib/OlmDevice.js
index a040ca522..f0df58523 100644
--- a/lib/OlmDevice.js
+++ b/lib/OlmDevice.js
@@ -15,6 +15,12 @@ limitations under the License.
 */
 "use strict";
 
+/**
+ * olm.js wrapper
+ *
+ * @module OlmDevice
+ */
+
 var Olm = require("olm");
 var utils = require("./utils");
 
@@ -25,6 +31,8 @@ var utils = require("./utils");
  * Accounts and sessions are kept pickled in a sessionStore.
  *
  * @constructor
+ * @alias module:OlmDevice
+ *
  * @param {Object} sessionStore A store to be used for data in end-to-end
  *    crypto
  *
diff --git a/lib/client.js b/lib/client.js
index 3a77c1d9a..31e4de826 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -2315,7 +2315,7 @@ MatrixClient.prototype.getTurnServers = function() {
  * appear in a room's timeline. If "<b>chronological</b>", messages will appear
  * in the timeline when the call to <code>sendEvent</code> was made. If
  * "<b>detached</b>", pending messages will appear in a separate list,
- * accessbile via {@link module:models/room~Room#getPendingEvents}. Default:
+ * accessbile via {@link module:models/room#getPendingEvents}. Default:
  * "chronological".
  *
  * @param {Number=} opts.pollTimeout The number of milliseconds to wait on /events.
diff --git a/lib/crypto-algorithms/base.js b/lib/crypto-algorithms/base.js
new file mode 100644
index 000000000..95b335ff5
--- /dev/null
+++ b/lib/crypto-algorithms/base.js
@@ -0,0 +1,137 @@
+/*
+Copyright 2016 OpenMarket Ltd
+
+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.
+*/
+"use strict";
+
+/**
+ * Internal module. Defines the base classes of the encryption implementations
+ *
+ * @module crypto-algorithms/base
+ */
+
+var utils = require("../utils");
+
+/**
+ * map of registered encryption algorithm classes. A map from string to {@link
+ * module:crypto-algorithms/base.EncryptionAlgorithm|EncryptionAlgorithm} class
+ *
+ * @type {Object.<string, function(new: module:crypto-algorithms/base.EncryptionAlgorithm)>}
+ */
+module.exports.ENCRYPTION_CLASSES = {};
+
+/**
+ * map of registered encryption algorithm classes. Map from string to {@link
+ * module:crypto-algorithms/base.DecryptionAlgorithm|DecryptionAlgorithm} class
+ *
+ * @type {Object.<string, function(new: module:crypto-algorithms/base.DecryptionAlgorithm)>}
+ */
+module.exports.DECRYPTION_CLASSES = {};
+
+/**
+ * base type for encryption implementations
+ *
+ * @constructor
+ *
+ * @param {string} deviceId The identifier for this device.
+ * @param {module:crypto} crypto crypto core
+ * @param {module:OlmDevice} olmDevice olm.js wrapper
+ */
+module.exports.EncryptionAlgorithm = function(deviceId, crypto, olmDevice) {
+    this._deviceId = deviceId;
+    this._crypto = crypto;
+    this._olmDevice = olmDevice;
+};
+
+/**
+ * Initialise this EncryptionAlgorithm instance for a particular room
+ *
+ * @method module:crypto-algorithms/base.EncryptionAlgorithm#initRoomEncryption
+ * @abstract
+ *
+ * @param {string[]} roomMembers list of currently-joined users in the room
+ * @return {module:client.Promise} Promise which resolves when setup is complete
+ */
+
+/**
+ * Encrypt a message event
+ *
+ * @method module:crypto-algorithms/base.EncryptionAlgorithm#encryptMessage
+ * @abstract
+ *
+ * @param {module:models/room} room
+ * @param {string} eventType
+ * @param {object} plaintext event content
+ *
+ * @return {object} new event body
+ */
+
+
+/**
+ * base type for decryption implementations
+ *
+ * @constructor
+ * @param {string} deviceId The identifier for this device.
+ * @param {module:crypto} crypto crypto core
+ * @param {module:OlmDevice} olmDevice olm.js wrapper
+ */
+module.exports.DecryptionAlgorithm = function(deviceId, crypto, olmDevice) {
+    this._deviceId = deviceId;
+    this._crypto = crypto;
+    this._olmDevice = olmDevice;
+};
+
+/**
+ * Decrypt an event
+ *
+ * @method module:crypto-algorithms/base.DecryptionAlgorithm#decryptEvent
+ * @abstract
+ *
+ * @param {object} event raw event
+ *
+ * @return {object} decrypted payload (with properties 'type', 'content')
+ *
+ * @throws {module:crypto-algorithms/base.DecryptionError} if there is a
+ *   problem decrypting the event
+ */
+
+/**
+ * Exception thrown when decryption fails
+ *
+ * @constructor
+ * @param {string} msg message describing the problem
+ * @extends Error
+ */
+module.exports.DecryptionError = function(msg) {
+    this.message = msg;
+};
+utils.inherits(module.exports.DecryptionError, Error);
+
+/**
+ * Registers an encryption/decryption class for a particular algorithm
+ *
+ * @param {string} algorithm algorithm tag to register for
+ *
+ * @param {class} encryptor {@link
+ *     module:crypto-algorithms/base.EncryptionAlgorithm|EncryptionAlgorithm}
+ *     implementation
+ *
+ * @param {class} decryptor {@link
+ *     module:crypto-algorithms/base.DecryptionAlgorithm|DecryptionAlgorithm}
+ *     implementation
+ */
+module.exports.registerAlgorithm = function(algorithm, encryptor, decryptor) {
+    module.exports.ENCRYPTION_CLASSES[algorithm] = encryptor;
+    module.exports.DECRYPTION_CLASSES[algorithm] = decryptor;
+};
diff --git a/lib/crypto-algorithms/index.js b/lib/crypto-algorithms/index.js
new file mode 100644
index 000000000..6a35c366f
--- /dev/null
+++ b/lib/crypto-algorithms/index.js
@@ -0,0 +1,39 @@
+/*
+Copyright 2016 OpenMarket Ltd
+
+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.
+*/
+"use strict";
+
+/**
+ * @module crypto-algorithms
+ */
+
+var base = require("./base");
+
+require("./olm");
+
+/**
+ * @see module:crypto-algorithms/base.ENCRYPTION_CLASSES
+ */
+module.exports.ENCRYPTION_CLASSES = base.ENCRYPTION_CLASSES;
+
+/**
+ * @see module:crypto-algorithms/base.DECRYPTION_CLASSES
+ */
+module.exports.DECRYPTION_CLASSES = base.DECRYPTION_CLASSES;
+
+/**
+ * @see module:crypto-algorithms/base.DecryptionError
+ */
+module.exports.DecryptionError = base.DecryptionError;
diff --git a/lib/crypto-algorithms/olm.js b/lib/crypto-algorithms/olm.js
new file mode 100644
index 000000000..b8229c9b3
--- /dev/null
+++ b/lib/crypto-algorithms/olm.js
@@ -0,0 +1,218 @@
+/*
+Copyright 2016 OpenMarket Ltd
+
+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.
+*/
+"use strict";
+
+/**
+ * Defines m.olm encryption/decryption
+ *
+ * @module crypto-algorithms/olm
+ */
+
+var utils = require("../utils");
+
+var base = require("./base");
+
+var OLM_ALGORITHM = "m.olm.v1.curve25519-aes-sha2";
+
+/**
+ * Olm encryption implementation
+ *
+ * @constructor
+ * @extends {module:crypto-algorithms/base.EncryptionAlgorithm}
+ *
+ * @param {string} deviceId The identifier for this device.
+ * @param {module:crypto} crypto crypto core
+ * @param {module:OlmDevice} olmDevice olm.js wrapper
+ *
+ */
+function OlmEncryption(deviceId, crypto, olmDevice) {
+    base.EncryptionAlgorithm.call(this, deviceId, crypto, olmDevice);
+}
+utils.inherits(OlmEncryption, base.EncryptionAlgorithm);
+
+/**
+ * @inheritdoc
+ * @param {string[]} roomMembers list of currently-joined users in the room
+ * @return {module:client.Promise} Promise which resolves when setup is complete
+ */
+OlmEncryption.prototype.initRoomEncryption = function(roomMembers) {
+    var crypto = this._crypto;
+    return crypto.downloadKeys(roomMembers, true).then(function(res) {
+        return crypto.ensureOlmSessionsForUsers(roomMembers);
+    });
+};
+
+/**
+ * @inheritdoc
+ *
+ * @param {module:models/room} room
+ * @param {string} eventType
+ * @param {object} plaintext event content
+ *
+ * @return {object} new event body
+ */
+OlmEncryption.prototype.encryptMessage = function(room, eventType, content) {
+    if (!room) {
+        throw new Error("Cannot send encrypted messages in unknown rooms");
+    }
+
+    // pick the list of recipients based on the membership list.
+    //
+    // TODO: there is a race condition here! What if a new user turns up
+    // just as you are sending a secret message?
+
+    var users = utils.map(room.getJoinedMembers(), function(u) {
+        return u.userId;
+    });
+
+    var participantKeys = [];
+    for (var i = 0; i < users.length; ++i) {
+        var userId = users[i];
+        var devices = this._crypto.getStoredDevicesForUser(userId);
+        for (var j = 0; j < devices.length; ++j) {
+            var dev = devices[j];
+            if (dev.blocked) {
+                continue;
+            }
+
+            for (var keyId in dev.keys) {
+                if (keyId.indexOf("curve25519:") === 0) {
+                    participantKeys.push(dev.keys[keyId]);
+                }
+            }
+        }
+    }
+    participantKeys.sort();
+    var participantHash = ""; // Olm.sha256(participantKeys.join());
+    var payloadJson = {
+        room_id: room.roomId,
+        type: eventType,
+        fingerprint: participantHash,
+        sender_device: this._deviceId,
+        content: content
+    };
+    var ciphertext = {};
+    var payloadString = JSON.stringify(payloadJson);
+    for (i = 0; i < participantKeys.length; ++i) {
+        var deviceKey = participantKeys[i];
+        if (deviceKey == this._olmDevice.deviceCurve25519Key) {
+            continue;
+        }
+        var sessionIds = this._olmDevice.getSessionIdsForDevice(deviceKey);
+        // Use the session with the lowest ID.
+        sessionIds.sort();
+        if (sessionIds.length === 0) {
+            // If we don't have a session for a device then
+            // we can't encrypt a message for it.
+            continue;
+        }
+        var sessionId = sessionIds[0];
+        console.log("Using sessionid " + sessionId + " for device " + deviceKey);
+        ciphertext[deviceKey] = this._olmDevice.encryptMessage(
+            deviceKey, sessionId, payloadString
+        );
+    }
+    var encryptedContent = {
+        algorithm: OLM_ALGORITHM,
+        sender_key: this._olmDevice.deviceCurve25519Key,
+        ciphertext: ciphertext
+    };
+    return encryptedContent;
+};
+
+/**
+ * Olm decryption implementation
+ *
+ * @constructor
+ * @extends {module:crypto-algorithms/base.DecryptionAlgorithm}
+ *
+ * @param {string} deviceId The identifier for this device.
+ * @param {module:crypto} crypto crypto core
+ * @param {module:OlmDevice} olmDevice olm.js wrapper
+ *
+ */
+function OlmDecryption(deviceId, crypto, olmDevice) {
+    base.DecryptionAlgorithm.call(this, deviceId, crypto, olmDevice);
+}
+utils.inherits(OlmDecryption, base.DecryptionAlgorithm);
+
+/**
+ * @inheritdoc
+ *
+ * @param {object} event raw event
+ *
+ * @return {object} decrypted payload (with properties 'type', 'content')
+ *
+ * @throws {module:crypto-algorithms/base.DecryptionError} if there is a
+ *   problem decrypting the event
+ */
+OlmDecryption.prototype.decryptEvent = function(event) {
+    var content = event.content;
+    var deviceKey = content.sender_key;
+    var ciphertext = content.ciphertext;
+
+    if (!ciphertext) {
+        throw new base.DecryptionError("Missing ciphertext");
+    }
+
+    if (!(this._olmDevice.deviceCurve25519Key in content.ciphertext)) {
+        throw new base.DecryptionError("Not included in recipients");
+    }
+
+    var message = content.ciphertext[this._olmDevice.deviceCurve25519Key];
+    var sessionIds = this._olmDevice.getSessionIdsForDevice(deviceKey);
+    var payloadString = null;
+    var foundSession = false;
+    for (var i = 0; i < sessionIds.length; i++) {
+        var sessionId = sessionIds[i];
+        var res = this._olmDevice.decryptMessage(
+            deviceKey, sessionId, message.type, message.body
+        );
+        payloadString = res.payload;
+        if (payloadString) {
+            console.log("decrypted with sessionId " + sessionId);
+            break;
+        }
+
+        if (res.matchesInbound) {
+            // this was a prekey message which matched this session; don't
+            // create a new session.
+            foundSession = true;
+            break;
+        }
+    }
+
+    if (message.type === 0 && !foundSession && payloadString === null) {
+        try {
+            payloadString = this._olmDevice.createInboundSession(
+                deviceKey, message.type, message.body
+            );
+            console.log("created new inbound sesion");
+        } catch (e) {
+            // Failed to decrypt with a new session.
+        }
+    }
+
+    // TODO: Check the sender user id matches the sender key.
+    // TODO: check the room_id and fingerprint
+    if (payloadString !== null) {
+        return JSON.parse(payloadString);
+    } else {
+        throw new base.DecryptionError("Bad Encrypted Message");
+    }
+};
+
+base.registerAlgorithm(OLM_ALGORITHM, OlmEncryption, OlmDecryption);
diff --git a/lib/crypto.js b/lib/crypto.js
index 99eaa18f4..80923bb8f 100644
--- a/lib/crypto.js
+++ b/lib/crypto.js
@@ -23,11 +23,15 @@ limitations under the License.
 var anotherjson = require('another-json');
 var q = require("q");
 
-var utils = require("./utils");
 var OlmDevice = require("./OlmDevice");
 
+var algorithms = require("./crypto-algorithms");
+
 var OLM_ALGORITHM = "m.olm.v1.curve25519-aes-sha2";
 
+/**
+ * @enum
+ */
 var DeviceVerification = {
     VERIFIED: 1,
     UNVERIFIED: 0,
@@ -46,7 +50,7 @@ var DeviceVerification = {
   * @property {Object.<string,string>} keys a map from
   *      &lt;key type&gt;:&lt;id&gt; -> &lt;base64-encoded key&gt;>
   *
-  * @property {DeviceVerification} verified whether the device has been
+  * @property {module:crypto~DeviceVerification} verified whether the device has been
   *     verified by the user
   *
   * @property {Object} unsigned  additional data from the homeserver
@@ -119,6 +123,7 @@ DeviceInfo.prototype.getDisplayname = function() {
 /**
  * Cryptography bits
  *
+ * @alias module:crypto.Crypto
  * @constructor
  * @alias module:crypto
  *
@@ -137,10 +142,10 @@ function Crypto(baseApis, sessionStore, userId, deviceId) {
     this._userId = userId;
     this._deviceId = deviceId;
 
-    this._cryptoAlgorithms = [];
-
     this._olmDevice = new OlmDevice(sessionStore);
-    this._cryptoAlgorithms = [OLM_ALGORITHM];
+
+    // EncryptionAlgorithm instance for each room
+    this._roomAlgorithms = {};
 
     // build our device keys: these will later be uploaded
     this._deviceKeys = {};
@@ -152,7 +157,7 @@ function Crypto(baseApis, sessionStore, userId, deviceId) {
     // add our own deviceinfo to the sessionstore
     var deviceInfo = {
         keys: this._deviceKeys,
-        algorithms: this._cryptoAlgorithms,
+        algorithms: [OLM_ALGORITHM],
         verified: DeviceVerification.VERIFIED,
     };
     var myDevices = this._sessionStore.getEndToEndDevicesForUser(
@@ -205,7 +210,7 @@ function _uploadDeviceKeys(crypto) {
     var deviceId = crypto._deviceId;
 
     var deviceKeys = {
-        algorithms: crypto._cryptoAlgorithms,
+        algorithms: [OLM_ALGORITHM],
         device_id: deviceId,
         keys: crypto._deviceKeys,
         user_id: userId,
@@ -388,7 +393,6 @@ function _storeDeviceKeys(_olmDevice, userId, deviceId, userStore, deviceResult)
     delete deviceResult.signatures;
     var json = anotherjson.stringify(deviceResult);
 
-    console.log("msg:", json);
     try {
         _olmDevice.verifySignature(signKey, json, signature);
     } catch (e) {
@@ -599,8 +603,6 @@ Crypto.prototype.isSenderKeyVerified = function(userId, algorithm, sender_key) {
  * @return {Object} A promise that will resolve when encryption is setup.
  */
 Crypto.prototype.setRoomEncryption = function(roomId, config, roomMembers) {
-    var self = this;
-
     // if we already have encryption in this room, we should ignore this event
     // (for now at least. maybe we should alert the user somehow?)
     var existingConfig = this._sessionStore.getEndToEndRoom(roomId);
@@ -608,23 +610,24 @@ Crypto.prototype.setRoomEncryption = function(roomId, config, roomMembers) {
         if (JSON.stringify(existingConfig) != JSON.stringify(config)) {
             console.error("Ignoring m.room.encryption event which requests " +
                           "a change of config in " + roomId);
-            return;
+            return q();
         }
     }
 
-    if (config.algorithm !== OLM_ALGORITHM) {
-        throw new Error("Unknown algorithm: " + config.algorithm);
+    var AlgClass = algorithms.ENCRYPTION_CLASSES[config.algorithm];
+    if (!AlgClass) {
+        throw new Error("Unable to encrypt with " + config.algorithm);
     }
 
     // remove spurious keys
     config = {
-        algorithm: OLM_ALGORITHM,
+        algorithm: config.algorithm,
     };
     this._sessionStore.storeEndToEndRoom(roomId, config);
 
-    return self.downloadKeys(roomMembers, true).then(function(res) {
-        return self._ensureOlmSessionsForUsers(roomMembers);
-    });
+    var alg = new AlgClass(this._deviceId, this, this._olmDevice);
+    this._roomAlgorithms[roomId] = alg;
+    return alg.initRoomEncryption(roomMembers);
 };
 
 /**
@@ -636,10 +639,8 @@ Crypto.prototype.setRoomEncryption = function(roomId, config, roomMembers) {
  *  an object with keys <tt>missingUsers</tt> (a list of users with no known
  *  olm devices), and <tt>missingDevices</tt> a list of olm devices with no
  *  known one-time keys.
- *
- * @private
  */
-Crypto.prototype._ensureOlmSessionsForUsers = function(users) {
+Crypto.prototype.ensureOlmSessionsForUsers = function(users) {
     var devicesWithoutSession = [];
     var userWithoutDevices = [];
     for (var i = 0; i < users.length; ++i) {
@@ -710,7 +711,7 @@ Crypto.prototype._ensureOlmSessionsForUsers = function(users) {
  * @return {bool} whether encryption is enabled.
  */
 Crypto.prototype.isRoomEncrypted = function(roomId) {
-    return (this._sessionStore.getEndToEndRoom(roomId) && true) || false;
+    return Boolean(this._roomAlgorithms[roomId]);
 };
 
 
@@ -718,7 +719,7 @@ Crypto.prototype.isRoomEncrypted = function(roomId) {
  * Encrypt an event according to the configuration of the room, if necessary.
  *
  * @param {module:models/event.MatrixEvent} event  event to be sent
- * @param {module:models/room.Room} room  destination room
+ * @param {module:models/room} room  destination room
  */
 Crypto.prototype.encryptEventIfNeeded = function(event, room) {
     if (event.isEncrypted()) {
@@ -735,112 +736,27 @@ Crypto.prototype.encryptEventIfNeeded = function(event, room) {
 
     var roomId = event.getRoomId();
 
-    var e2eRoomInfo = this._sessionStore.getEndToEndRoom(roomId);
-    if (!e2eRoomInfo || !e2eRoomInfo.algorithm) {
+    var alg = this._roomAlgorithms[roomId];
+    if (!alg) {
         // not encrypting messages in this room
+
+        // check that the HS hasn't hidden the crypto event
+        if (this._sessionStore.getEndToEndRoom(roomId)) {
+            throw new Error(
+                "Room was previously configured to use encryption, but is " +
+                "no longer. Perhaps the homeserver is hiding the " +
+                "configuration event."
+            );
+        }
         return;
     }
 
-    var encryptedContent = this._encryptMessage(
-         room, e2eRoomInfo, event.getType(), event.getContent()
+    var encryptedContent = alg.encryptMessage(
+         room, event.getType(), event.getContent()
     );
     event.makeEncrypted("m.room.encrypted", encryptedContent);
 };
 
-/**
- *
- * @param {module:models/room.Room} room
- * @param {object} e2eRoomInfo
- * @param {string} eventType
- * @param {object} content
- *
- * @return {object} new event body
- *
- * @private
- */
-Crypto.prototype._encryptMessage = function(room, e2eRoomInfo, eventType, content) {
-    if (e2eRoomInfo.algorithm !== OLM_ALGORITHM) {
-        throw new Error("Unknown end-to-end algorithm: " + e2eRoomInfo.algorithm);
-    }
-
-    if (!room) {
-        throw new Error("Cannot send encrypted messages in unknown rooms");
-    }
-
-    // pick the list of recipients based on the membership list.
-    //
-    // TODO: there is a race condition here! What if a new user turns up
-    // just as you are sending a secret message?
-
-    var users = utils.map(room.getJoinedMembers(), function(u) {
-        return u.userId;
-    });
-
-    var participantKeys = [];
-    for (var i = 0; i < users.length; ++i) {
-        var userId = users[i];
-        var devices = this.getStoredDevicesForUser(userId);
-        for (var j = 0; j < devices.length; ++j) {
-            var dev = devices[j];
-            if (dev.blocked) {
-                continue;
-            }
-
-            for (var keyId in dev.keys) {
-                if (keyId.indexOf("curve25519:") === 0) {
-                    participantKeys.push(dev.keys[keyId]);
-                }
-            }
-        }
-    }
-    participantKeys.sort();
-    var participantHash = ""; // Olm.sha256(participantKeys.join());
-    var payloadJson = {
-        room_id: room.roomId,
-        type: eventType,
-        fingerprint: participantHash,
-        sender_device: this._deviceId,
-        content: content
-    };
-    var ciphertext = {};
-    var payloadString = JSON.stringify(payloadJson);
-    for (i = 0; i < participantKeys.length; ++i) {
-        var deviceKey = participantKeys[i];
-        if (deviceKey == this._olmDevice.deviceCurve25519Key) {
-            continue;
-        }
-        var sessionIds = this._olmDevice.getSessionIdsForDevice(deviceKey);
-        // Use the session with the lowest ID.
-        sessionIds.sort();
-        if (sessionIds.length === 0) {
-            // If we don't have a session for a device then
-            // we can't encrypt a message for it.
-            continue;
-        }
-        var sessionId = sessionIds[0];
-        console.log("Using sessionid " + sessionId + " for device " + deviceKey);
-        ciphertext[deviceKey] = this._olmDevice.encryptMessage(
-            deviceKey, sessionId, payloadString
-        );
-    }
-    var encryptedContent = {
-        algorithm: e2eRoomInfo.algorithm,
-        sender_key: this._olmDevice.deviceCurve25519Key,
-        ciphertext: ciphertext
-    };
-    return encryptedContent;
-};
-
-function DecryptionError(msg) {
-    this.message = msg;
-}
-utils.inherits(DecryptionError, Error);
-
-/**
- * Exception thrown when decryption fails
- */
-Crypto.DecryptionError = DecryptionError;
-
 /**
  * Decrypt a received event
  *
@@ -848,66 +764,23 @@ Crypto.DecryptionError = DecryptionError;
  *
  * @return {object} decrypted payload (with properties 'type', 'content')
  *
- * @raises {DecryptionError} if there is a problem decrypting the event
+ * @raises {algorithms.DecryptionError} if there is a problem decrypting the event
  */
 Crypto.prototype.decryptEvent = function(event) {
     var content = event.content;
-    if (content.algorithm !== OLM_ALGORITHM) {
-        throw new DecryptionError("Unknown algorithm");
-    }
-
-    var deviceKey = content.sender_key;
-    var ciphertext = content.ciphertext;
-
-    if (!ciphertext) {
-        throw new DecryptionError("Missing ciphertext");
-    }
-
-    if (!(this._olmDevice.deviceCurve25519Key in content.ciphertext)) {
-        throw new DecryptionError("Not included in recipients");
-    }
-
-    var message = content.ciphertext[this._olmDevice.deviceCurve25519Key];
-    var sessionIds = this._olmDevice.getSessionIdsForDevice(deviceKey);
-    var payloadString = null;
-    var foundSession = false;
-    for (var i = 0; i < sessionIds.length; i++) {
-        var sessionId = sessionIds[i];
-        var res = this._olmDevice.decryptMessage(
-            deviceKey, sessionId, message.type, message.body
-        );
-        payloadString = res.payload;
-        if (payloadString) {
-            console.log("decrypted with sessionId " + sessionId);
-            break;
-        }
-
-        if (res.matchesInbound) {
-            // this was a prekey message which matched this session; don't
-            // create a new session.
-            foundSession = true;
-            break;
-        }
-    }
-
-    if (message.type === 0 && !foundSession && payloadString === null) {
-        try {
-            payloadString = this._olmDevice.createInboundSession(
-                deviceKey, message.type, message.body
-            );
-            console.log("created new inbound sesion");
-        } catch (e) {
-            // Failed to decrypt with a new session.
-        }
-    }
-
-    // TODO: Check the sender user id matches the sender key.
-    if (payloadString !== null) {
-        return JSON.parse(payloadString);
-    } else {
-        throw new DecryptionError("Bad Encrypted Message");
+    var AlgClass = algorithms.DECRYPTION_CLASSES[content.algorithm];
+    if (!AlgClass) {
+        throw new algorithms.DecryptionError("Unable to decrypt " + content.algorithm);
     }
+    var alg = new AlgClass(this._deviceId, this, this._olmDevice);
+    return alg.decryptEvent(event);
 };
 
+/**
+ * @see module:crypto-algorithms/base.DecryptionError
+ */
+Crypto.DecryptionError = algorithms.DecryptionError;
+
+
 /** */
 module.exports = Crypto;
diff --git a/lib/matrix.js b/lib/matrix.js
index 8612527e9..4a8528cd9 100644
--- a/lib/matrix.js
+++ b/lib/matrix.js
@@ -30,7 +30,7 @@ module.exports.MatrixHttpApi = require("./http-api").MatrixHttpApi;
 module.exports.MatrixError = require("./http-api").MatrixError;
 /** The {@link module:client.MatrixClient|MatrixClient} class. */
 module.exports.MatrixClient = require("./client").MatrixClient;
-/** The {@link module:models/room~Room|Room} class. */
+/** The {@link module:models/room|Room} class. */
 module.exports.Room = require("./models/room");
 /** The {@link module:models/event-timeline~EventTimeline} class. */
 module.exports.EventTimeline = require("./models/event-timeline");
diff --git a/lib/models/room.js b/lib/models/room.js
index cc8e955a5..7bf9b127f 100644
--- a/lib/models/room.js
+++ b/lib/models/room.js
@@ -75,6 +75,7 @@ function synthesizeReceipt(userId, event, receiptType) {
  * map from event_id to timeline and index.
  *
  * @constructor
+ * @alias module:models/room
  * @param {string} roomId Required. The ID of this room.
  * @param {Object=} opts Configuration options
  * @param {*} opts.storageToken Optional. The token which a data store can use
@@ -85,7 +86,7 @@ function synthesizeReceipt(userId, event, receiptType) {
  * appear in a room's timeline. If "<b>chronological</b>", messages will appear
  * in the timeline when the call to <code>sendEvent</code> was made. If
  * "<b>detached</b>", pending messages will appear in a separate list,
- * accessbile via {@link module:models/room~Room#getPendingEvents}. Default:
+ * accessbile via {@link module:models/room#getPendingEvents}. Default:
  * "chronological".
  *
  * @param {boolean} [opts.timelineSupport = false] Set to true to enable improved
diff --git a/lib/timeline-window.js b/lib/timeline-window.js
index 539429982..89acec9dc 100644
--- a/lib/timeline-window.js
+++ b/lib/timeline-window.js
@@ -41,7 +41,7 @@ var DEFAULT_PAGINATE_LOOP_LIMIT = 5;
  * Construct a TimelineWindow.
  *
  * <p>This abstracts the separate timelines in a Matrix {@link
- * module:models/room~Room|Room} into a single iterable thing. It keeps track of
+ * module:models/room|Room} into a single iterable thing. It keeps track of
  * the start and endpoints of the window, which can be advanced with the help
  * of pagination requests.
  *