diff --git a/lib/account.js b/lib/account.js
index e1f8953..24f44ec 100644
--- a/lib/account.js
+++ b/lib/account.js
@@ -1,558 +1,559 @@
 'use strict';
 
 import debug from 'debug';
 import md5 from 'blueimp-md5';
 import transform from 'sdp-transform';
 import utils from './utils';
 
 import { EventEmitter } from 'events';
 import { Call } from './call';
 import { ConferenceCall } from './conference';
 import { Message } from './message';
 import { PGP } from './pgp';
 
 const DEBUG = debug('sylkrtc:Account');
 
 
 class Account extends EventEmitter {
     constructor(options, connection) {
         if (options.account.indexOf('@') === -1) {
             throw new Error('Invalid account id specified');
         }
         super();
         const id = options.account;
         const [username, domain] = id.split('@');
         this._id = id;
         this._displayName = options.displayName;
         if (options.hasOwnProperty('ha1') && !options.ha1) {
             this._password = options.password;
         } else {
             this._password = md5(username + ':' + (options.realm || domain) + ':' + options.password);
         }
         this._pgp = null;
         this._connection = connection;
         this._registrationState = null;
         this._calls = new Map();
         this._confCalls = new Map();
         this._messages = new Map();
     }
 
     get id() {
         return this._id;
     }
 
     get password() {
         return this._password;
     }
 
     get displayName() {
         return this._displayName;
     }
 
     get registrationState() {
         return this._registrationState;
     }
 
     get messages() {
         return Array.from(this._messages.values());
     }
 
     get pgp() {
         return this._pgp;
     }
 
     register() {
         const req = {
             sylkrtc: 'account-register',
             account: this._id
         };
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Register error: %s', error);
                 const oldState = this._registrationState;
                 const newState = 'failed';
                 const data = {reason: error.toString()};
                 this._registrationState = newState;
                 this.emit('registrationStateChanged', oldState, newState, data);
             }
         });
     }
 
     unregister() {
         const req = {
             sylkrtc: 'account-unregister',
             account: this._id,
         };
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Unregister error: %s', error);
             }
             const oldState = this._registrationState;
             const newState = null;
             this._registrationState = newState;
             this.emit('registrationStateChanged', oldState, newState, {});
         });
     }
 
     call(uri, options={}) {
         const callObj = new Call(this);
         callObj._initOutgoing(uri, options);
         this._calls.set(callObj.id, callObj);
         this.emit('outgoingCall', callObj);
         return callObj;
     }
 
     joinConference(uri, options={}) {
         const confCall = new ConferenceCall(this);
         confCall._initialize(uri, options);
         this._confCalls.set(confCall.id, confCall);
         this.emit('conferenceCall', confCall);
         return confCall;
     }
 
     setDeviceToken(token, platform, device, silent, app) {
         DEBUG('Setting device token: %s', token);
         const req = {
             sylkrtc: 'account-devicetoken',
             account: this._id,
             token,
             platform,
             device,
             silent,
             app
         };
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Error setting device token: %s', error);
             }
         });
     }
 
     addPGPKeys(keys) {
         this._pgp = new PGP(keys, this._connection);
     }
 
     generatePGPKeys(cb=null) {
         if (this._pgp === null) {
             this._pgp = new PGP({}, this._connection);
         }
         this._pgp.generatePGPKeys((result) => {
             this.emit('privateKeysGenerated', result);
             cb(result);
         });
     }
 
     checkIfKeyExists(cb=null) {
         this._connection.lookupPublicKey(this._id);
         new Promise((resolve, reject) => {
             this._connection.once('publicKey', (message) => {
                 if (message.publicKey) {
                     message.publicKey = message.publicKey.trim();
                 }
                 resolve(message.publicKey);
             });
         }).then(publicKey => cb(publicKey));
     }
 
     decryptKeyImport(message, password, cb=null) {
         if (this._pgp === null) {
             this._pgp = new PGP({}, this._connection);
         }
         this._pgp.decryptKeyImport(message, password, (result) => {
+            this._pgp.terminateWorker();
             this._pgp = null;
             cb(result);
         });
     }
 
     exportPrivateKey(password) {
         if (this._pgp === null) {
             return;
         }
         this._pgp.exportKeys(password).then(result => {
             if (result.didEncrypt) {
                 this.sendMessage(this._id, result.message, 'text/pgp-private-key');
             }
         });
     }
 
     sendMessage(uri, message, contentType='text/plain', options={}, cb=null) {
         const outgoingMessage = new Message({
             account: uri,
             content: message,
             contentType,
             timestamp: options.timestamp || new Date().toISOString(),
             type: 'normal'
         }, new utils.Identity(this._id, this._displayName), 'pending');
 
         if (contentType !== 'text/pgp-private-key' && contentType !== 'text/pgp-public-key') {
             this._messages.set(outgoingMessage.id, outgoingMessage);
         }
 
         (async() => {
             let result = {};
             if (this._pgp !== null && contentType !== 'text/pgp-private-key' && contentType !== 'text/pgp-public-key') {
                 result = await this._pgp.encryptMessage(uri, outgoingMessage);
                 if (result.didEncrypt) {
                     outgoingMessage._isSecure = true;
                 }
             }
             const req = {
                 sylkrtc: 'account-message',
                 account: this._id,
                 uri: uri,
                 message_id: outgoingMessage.id,
                 content: result.message || message,
                 content_type: outgoingMessage.contentType,
                 timestamp: outgoingMessage.timestamp
             };
             if (contentType !== 'text/pgp-private-key' && contentType !== 'text/pgp-public-key') {
                 this.emit('sendingMessage', outgoingMessage);
             }
             DEBUG('Sending message: %o', outgoingMessage);
             this._sendRequest(req, (error) => {
                 if (error) {
                     DEBUG('Error sending message: %s', error);
                     outgoingMessage._setState('failed');
                 }
                 if (cb) {
                     cb(error);
                 }
             });
         })();
         return outgoingMessage;
     }
 
     sendDispositionNotification(uri, id, timestamp, state, cb=null) {
         const req = {
             sylkrtc: 'account-disposition-notification',
             account: this._id,
             uri: uri,
             message_id: id,
             state,
             timestamp
         };
         DEBUG('Sending disposition notification: %o', req);
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Error sending disposition notification: %s', error);
             } else {
                 const incomingMessage = this._messages.get(id);
                 if (incomingMessage) {
                     incomingMessage._setDispositionState(state);
                 }
             }
             this.emit('sendingDispositionNotification', id, state, error);
             if (cb) {
                 cb(error);
             }
         });
     }
 
     syncConversations(id=null, cb=null) {
         const req = {
             sylkrtc: 'account-sync-conversations',
             account: this._id,
             message_id: id
         };
         DEBUG('Sending replay journal: %o', req);
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Error sending sync request: %s', error);
             }
             if (cb) {
                 cb(error);
             }
         });
     }
 
     markConversationRead(contact) {
         const req = {
             sylkrtc: 'account-mark-conversation-read',
             account: this._id,
             contact: contact
         };
         DEBUG('Sending markConversationRead: %o', req);
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Error sending markConversationRead request: %s', error);
             }
         });
         this._readConversation(contact);
     }
 
     removeMessage(message, cb=null) {
         this._removeMessage(message.id);
         let contact = message.receiver;
         if (message.state === 'received') {
             contact = message.sender.uri;
         }
         const req = {
             sylkrtc: 'account-remove-message',
             account: this._id,
             message_id: message.id,
             contact: contact
         };
         DEBUG('Sending remove message: %o', req);
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Error sending remove message: %s', error);
             }
             if (cb) {
                 cb(error);
             }
         });
     }
 
     removeConversation(uri, cb=null) {
         this._removeConversation(uri);
         const req = {
             sylkrtc: 'account-remove-conversation',
             account: this._id,
             contact: uri
         };
         DEBUG('Sending remove conversation: %o', req);
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Error sending remove conversation: %s', error);
             }
             if (cb) {
                 cb(error);
             }
         });
     }
 
     // Private API
 
     _handleEvent(message) {
         DEBUG('Received account event: %s', message.event);
         const data = {};
         switch (message.event) {
             case 'registration-state':
                 const oldState = this._registrationState;
                 const newState = message.state;
                 this._registrationState = newState;
                 if (newState === 'failed') {
                     data.reason = message.reason;
                 }
                 this.emit('registrationStateChanged', oldState, newState, data);
                 break;
             case 'incoming-session':
                 let call = new Call(this);
                 call._initIncoming(message.session, message.originator, message.sdp, message.call_id);
                 this._calls.set(call.id, call);
                 // see what media types are offered
                 const mediaTypes = { audio: false, video: false };
                 const parsedSdp = transform.parse(message.sdp);
                 for (let media of parsedSdp.media) {
                     if (media.type === 'audio' && media.port !== 0 && media.direction === 'sendrecv') {
                         mediaTypes.audio = true;
                     } else if (media.type === 'video' && media.port !== 0 && media.direction === 'sendrecv') {
                         mediaTypes.video = true;
                     }
                 }
                 DEBUG('Incoming call from %s with media types: %o', message.originator.uri, mediaTypes);
                 this.emit('incomingCall', call, mediaTypes);
                 break;
             case 'missed-session':
                 data.originator = new utils.Identity(message.originator.uri, message.originator.display_name);
                 this.emit('missedCall', data);
                 break;
             case 'conference-invite':
                 data.originator = new utils.Identity(message.originator.uri, message.originator.display_name);
                 data.room = message.room;
                 data.id = message.session_id;
                 this.emit('conferenceInvite', data);
                 break;
             case 'message':
                 DEBUG('Incoming message from %s: %o', message.sender.uri, message);
                 const incomingMessage = this._messages.get(message.message_id);
                 if (!incomingMessage) {
                     (async() => {
                         if (message.content.includes(`-----BEGIN PGP MESSAGE-----`)
                             && message.content.trim().endsWith(`-----END PGP MESSAGE-----`)
                             && message.content_type !== 'text/pgp-private-key'
                         ) {
                             if (this._pgp !== null) {
                                 message = await this._pgp.decryptMessage(message);
                                 if (message.didDecrypt) {
                                     message.isSecure = true;
                                 } else {
                                     // Decryption failed, add failure disposition
                                     return;
                                 }
                             }
                         }
 
                         if (message.content_type === 'text/pgp-private-key') {
                             DEBUG("Skipping message");
                             return;
                         }
 
                         const mappedMessage = new Message(
                             message,
                             new utils.Identity(message.sender.uri, message.sender.display_name),
                             'received'
                         );
 
                         if (message.content_type === 'text/pgp-public-key') {
                             if (this._pgp !== null) {
                                 this._pgp.addPublicPGPKeys({[message.sender.uri]: mappedMessage.content});
                                 return;
                             }
                         }
                         this._messages.set(mappedMessage.id, mappedMessage);
                         this.emit('incomingMessage', mappedMessage);
 
                         if (message.disposition_notification && message.disposition_notification.indexOf('positive-delivery') !== -1) {
                             this.sendDispositionNotification(message.sender.uri, message.message_id, message.timestamp, 'delivered');
                         }
                     })();
                 }
                 break;
             case 'disposition-notification':
                 const outgoingMessage = this._messages.get(message.message_id);
                 if (outgoingMessage) {
                     if (outgoingMessage.state === 'displayed') {
                         break;
                     }
                     outgoingMessage._setState(message.state);
                 }
                 const {reason, code} = message;
                 this.emit('messageStateChanged', message.message_id, message.state, {reason, code});
                 break;
             case 'sync-conversations':
                 const specialContentTypes = new Set(['application/sylk-message-remove', 'message/imdn']);
                 let results = [];
 
                 (async() => {
                     if (this._pgp !== null) {
                         for (const message of message.messages) {
                             if ( message.content.includes(`-----BEGIN PGP MESSAGE-----`)
                                 && message.content.trim().endsWith(`-----END PGP MESSAGE-----`)
                             ) {
                                 await this._pgp.decryptMessage(message);
                             }
                         };
                     }
 
                     const messageList = message.messages.filter((message, idx) => {
                         if (message.content_type === 'text/pgp-public-key') {
                             DEBUG("Public key found, adding: %s", message.content);
                             if (this._pgp !== null) {
                                 this._pgp.addPublicPGPKeys({[message.sender.uri]: message.content});
                             }
                             return false;
                         }
                         if (message.didDecrypt === false) {
                             return false;
                         }
                         return true;
                     }).map((message, idx) => {
                         if (specialContentTypes.has(message.content_type)) {
                             message.content = JSON.parse(message.content);
                         }
 
                         message.isSecure = message.didDecrypt;
                         if (message.direction === "outgoing") {
                             message.account = message.contact;
                             return new Message(message, new utils.Identity(this._id, this._displayName), message.state);
                         } else {
                             message.account = this._id;
                             return new Message(message, new utils.Identity(message.contact, ''), message.state);
                         }
                     });
                     this.emit('syncConversations', messageList);
                 })();
                 break;
             case 'sync':
                 if (message.type === 'message') {
                     let content = message.content;
                     switch (message.action) {
                         case 'remove':
                             const existingMessage = this._messages.get(content.message_id);
                             if (existingMessage) {
                                 this.emit('removeMessage', existingMessage);
                                 this._removeMessage(message.content.message_id);
                             } else {
                                 content.account = content.contact;
                                 this.emit('removeMessage', new Message(content, new utils.Identity(content.contact, ''), ''));
                             }
                             break;
                         case 'add':
                             content.account = content.uri;
                             (async() => {
                                 if (content.content.includes(`-----BEGIN PGP MESSAGE-----`)
                                     && content.content.trim().endsWith(`-----END PGP MESSAGE-----`)
                                     && content.content_type !== 'text/pgp-private-key'
                                 ) {
                                     if (this._pgp !== null) {
                                         content = await this._pgp.decryptMessage(content);
                                         if (content.didDecrypt) {
                                             content.isSecure = true;
                                         } else {
                                             return;
                                         }
                                     }
                                 }
                                 const outgoingMessage = new Message(content, new utils.Identity(this._id, this._displayName), 'pending');
                                 if (content.content_type !== 'text/pgp-private-key' || content.content_type !== 'text/pgp-public-key') {
                                     this._messages.set(outgoingMessage.id, outgoingMessage);
                                     this.emit('sendingMessage', outgoingMessage);
                                 }
                                 this.emit('outgoingMessage', outgoingMessage);
                             })();
                             break;
                         default:
                             break;
                     }
                 }
                 if (message.type === 'conversation') {
                     switch(message.action) {
                         case 'remove':
                             this._removeConversation(message.content.contact);
                             this.emit('removeConversation', message.content.contact);
                             break;
                         case 'read':
                             this._readConversation(message.content.contact);
                             this.emit('readConversation', message.content.contact);
                             break;
                         default:
                             break;
                     }
                 }
                 break;
             default:
                 break;
         }
     }
 
     _removeMessage(id) {
         this._messages.delete(id);
     }
 
     _readConversation(uri) {
         for (let [id, message] of this._messages.entries()) {
             if (message.state === 'received' && message.sender.uri === uri && message.dispositionState !== 'displayed') {
                 message._setDispositionState('displayed');
             }
         }
     }
 
     _removeConversation(uri) {
         for (let [id, message] of this._messages.entries()) {
             if (message.state === 'received' && message.sender.uri === uri) {
                 this._messages.delete(id);
             } else if (message.receiver === uri) {
                 this._messages.delete(id);
             }
         }
     }
 
     _sendRequest(req, cb) {
         this._connection._sendRequest(req, cb);
     }
 
 }
 
 
 export { Account };
diff --git a/lib/pgp.js b/lib/pgp.js
index 475c93f..3776598 100644
--- a/lib/pgp.js
+++ b/lib/pgp.js
@@ -1,176 +1,186 @@
 'use strict';
 
 import debug from 'debug';
 import { EventEmitter } from 'events';
 import * as openpgp from 'openpgp';
 
 const DEBUG = debug('sylkrtc:PGP');
 
+const worker = new Worker('./worker.js');
 
 class PGP extends EventEmitter {
     constructor(options={}, connection) {
         super();
         this._privateKey = options.privateKey || null;
         this._publicKey = options.publicKey || null;
         this._armoredPrivateKey = options.privateKey || null;
         this._armoredPublicKey = options.publicKey || null;
         this._cachedPublicKeys = new Map();
         this._connection = connection;
 
         if (this._privateKey !== null) {
             openpgp.readPrivateKey({armoredKey: this._privateKey}).then(privateKey => {
                 if (options.password) {
                     return openpgp.decryptKey({privateKey: privateKey, passphrase: options.password});
                 }
                 return Promise.resolve(privateKey);
             }).then(privateKey => {
                 this._privateKey = privateKey;
             });
         }
 
         if (this._publicKey !== null) {
             openpgp.readKey({ armoredKey: this._publicKey }).then(publicKey =>
                 this._publicKey = publicKey
             );
         }
 
         if (this._privateKey && this._publicKey) {
             DEBUG('PGP messaging loaded and enabled');
         }
     }
 
     addPublicPGPKeys(keys) {
         for (let key of Object.keys(keys)) {
             this._cachedPublicKeys.set(key, keys[key]);
             this.emit('publicKeyAdded', {contact: key, key: keys[key]});
         }
     }
 
     generatePGPKeys(cb=null) {
         DEBUG('Generating PGP key');
         openpgp.generateKey({
             // we have to use rsa, Rreact native can't use elliptic curves
             type: 'rsa',
             rsaBits: 2048,
             // type: 'ecc',
             // curve: 'curve25519',
             userIDs: [{ name: this._displayName, email: this._id }], // you can pass multiple user IDs
             format: 'armored'
         }).then(result => {
             DEBUG('PGP key generated');
 
             this._armoredPublicKey = result.publicKey;
             this._armoredPrivateKey = result.privateKey;
 
             openpgp.readPrivateKey({ armoredKey: result.privateKey }).then(privateKey =>
                 this._privateKey = privateKey
             );
             openpgp.readKey({ armoredKey: result.publicKey }).then(publicKey =>
                 this._publicKey = publicKey
             );
             cb(result);
         });
     }
 
     exportKeys(password) {
         // let message = `${this._armoredPublicKey}\n${this._armoredPrivateKey}`.trim()
         const message = `${this._armoredPrivateKey}`.trim();
         return openpgp.createMessage({ text: message}).then(pgpMessage => {
             return openpgp.encrypt({
                 message: pgpMessage,
                 passwords: [password],
                 config: { preferredCompressionAlgorithm: openpgp.enums.compression.zlib }
             });
         }).then(encryptedMessage => {
             let fullMessage = `${this._armoredPublicKey}\n${encryptedMessage}`;
             return {message: fullMessage, didEncrypt: true};
         }).catch(() => {
             return {message: '', didEncrypt: false};
         });
     }
 
     decryptKeyImport(message, password, cb=null) {
         const regexp = /(?<before>[^]*)(?<pgpMessage>-----BEGIN PGP MESSAGE-----[^]*-----END PGP MESSAGE-----)(?<after>[^]*)/ig;
         let pgpMessage, after, before = null;
         let match = regexp.exec(message.content);
         do {
             pgpMessage = match.groups.pgpMessage;
             before = match.groups.before;
             after = match.groups.after;
         } while((match = regexp.exec(message.content)) !== null);
 
         return openpgp.readMessage({
             armoredMessage: pgpMessage // parse armored message
         }).then(message => {
             return openpgp.decrypt({message, passwords: [password]});
         }).then(data => {
             message._content = `${before}${data.data}${after}`;
             message.didDecrypt = true;
             cb(message);
             return message;
         }).catch((error) => {
             DEBUG("Can't decrypt key: %s", error);
             let result = Object.assign({}, {didDecrypt: false});
             cb(result);
             return result;
         });
     }
 
     encryptMessage(uri, message) {
         let pgpMessage = '';
         let key = '';
 
         DEBUG("Attempt to encrypt message (%s)", message.id);
         return this._lookupPublicKey(uri).then(publicKey => {
             key = publicKey;
             if (key === null) {
                 DEBUG("No public key found");
             }
             return openpgp.createMessage({ text: message.content});
         }).then(message => {
             pgpMessage = message;
             return openpgp.readKey({ armoredKey: key });
         }).then(publicKey => {
             return openpgp.encrypt({message: pgpMessage, encryptionKeys: [this._publicKey, publicKey]});
         }).then(encryptedMessage => {
             DEBUG("Message encrypted (%s)", message.id);
             return {message: encryptedMessage, didEncrypt: true};
         }).catch((error) => {
             DEBUG("Message not encrypted (%s): %s", message.id, error);
             return {message: message, didEncrypt: false};
         });
     }
 
+    terminateWorker() {
+        worker.terminate();
+    }
+
     decryptMessage(message) {
         DEBUG("Attempt to decrypt message (%s)", message.message_id);
-        return openpgp.readMessage({
-            armoredMessage: message.content // parse armored message
-        }).then(message => {
-            return openpgp.decrypt({message, decryptionKeys: this._privateKey});
-        }).then(data => {
-            DEBUG("Message decrypted (%s)", message.message_id);
-            return Object.assign(message, {content: data.data, didDecrypt: true});
-        }).catch((error) => {
-            DEBUG("Can't decrypt message (%s) %s", message.message_id, error);
-            return Object.assign(message, {didDecrypt: false});
+        return new Promise((resolve, reject) => {
+            const channel = new MessageChannel();
+            channel.port1.onmessage = function({ data }) {
+                if (data.error !== undefined) {
+                    DEBUG("Can't decrypt message (%s) %s", message.message_id, data.error);
+                    resolve(Object.assign(message, {didDecrypt: false}));
+                } else {
+                    DEBUG("Message decrypted (%s)", message.message_id);
+                    resolve(Object.assign(message, {content: data.result, didDecrypt: true}));
+                }
+            };
+            let action = 'decrypt';
+            let keys = { privateKey: this._armoredPrivateKey, publicKey: this._publicKey};
+            const msg = message.content;
+            worker.postMessage({ action, keys, msg }, [channel.port2]);
         });
     }
 
     _lookupPublicKey(uri) {
         let key = this._cachedPublicKeys.get(uri);
         if (key === undefined) {
             this._connection.lookupPublicKey(uri);
             return new Promise((resolve, reject) => {
                 this._connection.once('publicKey', (message) => {
                     DEBUG("Fetched public key from server for %s", message.uri);
                     this.addPublicPGPKeys({[message.uri]: message.publicKey});
                     resolve(message.public_key);
                 });
             });
         }
         return Promise.resolve(key);
     }
 }
 
 
 export { PGP };
diff --git a/lib/worker.js b/lib/worker.js
new file mode 100644
index 0000000..c45fd1a
--- /dev/null
+++ b/lib/worker.js
@@ -0,0 +1,34 @@
+'use strict';
+
+/* globals openpgp: true */
+
+import 'regenerator-runtime/runtime';
+import * as openpgp from 'openpgp';
+
+onmessage = async function({ data: { action, keys, msg, pass}, ports: [port] }) {
+    try {
+        let result;
+        switch (action) {
+            case 'decrypt': {
+                let privateKey;
+                if (pass) {
+                    privateKey = await openpgp.decryptKey({
+                        privateKey: await openpgp.readKey({ armoredKey: keys.privateKey }),
+                        passphrase: pass
+                    });
+                } else {
+                    privateKey = await openpgp.readKey({ armoredKey: keys.privateKey });
+                }
+                const { data } = await openpgp.decrypt({
+                    message: await openpgp.readMessage({ armoredMessage: msg }),
+                    decryptionKeys: privateKey
+                });
+                result = data;
+                break;
+            }
+        }
+        port.postMessage({ result });
+    } catch (e) {
+        port.postMessage({ error: e.message });
+    }
+};