diff --git a/src/js/crypto/nacl-crypto.js b/src/js/crypto/nacl-crypto.js
index 27f0610..8b0f6f1 100644
--- a/src/js/crypto/nacl-crypto.js
+++ b/src/js/crypto/nacl-crypto.js
@@ -42,9 +42,85 @@ var NaclCrypto = function(nacl, util) {
 	 * @param nonce [String] The base64 encoded nonce
 	 * @param recipientPk [String] The receiver's base64 encoded public key
 	 * @param senderSk [String] The sender's base64 encoded private key
-	 * @return [Object] The base64 encoded ciphertext and nonce
+	 * @return [String] The base64 encoded ciphertext
 	 */
-	this.asymEncrypt = function(plaintext, nonce, recipientPk, senderSk) {
+	this.asymEncrypt = function(plaintext, nonce, recipientPk, senderSk, callback) {
+		// convert to Uint8Array
+		var ptBuf = nacl.encode_utf8(plaintext);
+		var recipientPkBuf = nacl.encode_latin1(util.base642Str(recipientPk));
+		var senderSkBuf = nacl.encode_latin1(util.base642Str(senderSk));
+		var nonceBuf = nacl.encode_latin1(util.base642Str(nonce));
+
+		if (Worker) {
+
+			var worker = new Worker(app.config.workerPath + '/crypto/nacl-worker.js');
+			worker.onmessage = function(e) {
+				// encode to base64
+				callback(util.str2Base64(nacl.decode_latin1(e.data)));
+			};
+			worker.postMessage({
+				type: 'encrypt',
+				plaintext: ptBuf,
+				nonce: nonceBuf,
+				recipientPk: recipientPkBuf,
+				senderSk: senderSkBuf
+			});
+
+		} else {
+			// encrypt
+			var ct = nacl.crypto_box(ptBuf, nonceBuf, recipientPkBuf, senderSkBuf);
+			// encode to base64
+			callback(util.str2Base64(nacl.decode_latin1(ct)));
+		}
+	};
+
+	/**
+	 * Asymmetrically decrypt a String
+	 * @param ciphertext [String] The base64 encoded ciphertext
+	 * @param nonce [String] The base64 encoded nonce
+	 * @param senderPk [String] The sender's base64 encoded public key
+	 * @param recipientSk [String] The receiver's base64 encoded private key
+	 * @return [String] The decrypted plaintext in UTF8
+	 */
+	this.asymDecrypt = function(ciphertext, nonce, senderPk, recipientSk, callback) {
+		// convert to Uint8Array
+		var ctBuf = nacl.encode_latin1(util.base642Str(ciphertext));
+		var nonceBuf = nacl.encode_latin1(util.base642Str(nonce));
+		var senderPkBuf = nacl.encode_latin1(util.base642Str(senderPk));
+		var recipientSkBuf = nacl.encode_latin1(util.base642Str(recipientSk));
+
+		if (Worker) {
+
+			var worker = new Worker(app.config.workerPath + '/crypto/nacl-worker.js');
+			worker.onmessage = function(e) {
+				// decode to string
+				callback(nacl.decode_utf8(e.data));
+			};
+			worker.postMessage({
+				type: 'decrypt',
+				ciphertext: ctBuf,
+				nonce: nonceBuf,
+				senderPk: senderPkBuf,
+				recipienSk: recipientSkBuf
+			});
+
+		} else {
+			// decrypt
+			var pt = nacl.crypto_box_open(ctBuf, nonceBuf, senderPkBuf, recipientSkBuf);
+			// decode to string
+			callback(nacl.decode_utf8(pt));
+		}
+	};
+
+	/**
+	 * Asymmetrically encrypt a String
+	 * @param plaintext [String] The input string in UTF8
+	 * @param nonce [String] The base64 encoded nonce
+	 * @param recipientPk [String] The receiver's base64 encoded public key
+	 * @param senderSk [String] The sender's base64 encoded private key
+	 * @return [String] The base64 encoded ciphertext
+	 */
+	this.asymEncryptSync = function(plaintext, nonce, recipientPk, senderSk) {
 		// convert to Uint8Array
 		var ptBuf = nacl.encode_utf8(plaintext);
 		var recipientPkBuf = nacl.encode_latin1(util.base642Str(recipientPk));
@@ -66,7 +142,7 @@ var NaclCrypto = function(nacl, util) {
 	 * @param recipientSk [String] The receiver's base64 encoded private key
 	 * @return [String] The decrypted plaintext in UTF8
 	 */
-	this.asymDecrypt = function(ciphertext, nonce, senderPk, recipientSk) {
+	this.asymDecryptSync = function(ciphertext, nonce, senderPk, recipientSk) {
 		// convert to Uint8Array
 		var ctBuf = nacl.encode_latin1(util.base642Str(ciphertext));
 		var nonceBuf = nacl.encode_latin1(util.base642Str(nonce));
@@ -80,46 +156,6 @@ var NaclCrypto = function(nacl, util) {
 		return ptStr;
 	};
 
-	/**
-	 * Symmetrically encrypt a String
-	 * @param plaintext [String] The input string in UTF8
-	 * @param nonce [String] The base64 encoded nonce
-	 * @param secretKey [String] The receiver's base64 encoded public key
-	 * @return [Object] The base64 encoded ciphertext and nonce
-	 */
-	this.symEncrypt = function(plaintext, nonce, secretKey) {
-		// convert to Uint8Array
-		var ptBuf = nacl.encode_utf8(plaintext);
-		var secretKeyBuf = nacl.encode_latin1(util.base642Str(secretKey));
-		var nonceBuf = nacl.encode_latin1(util.base642Str(nonce));
-		// encrypt
-		var ct = nacl.crypto_secretbox(ptBuf, nonceBuf, secretKeyBuf);
-		// encode to base64
-		var ctBase64 = util.str2Base64(nacl.decode_latin1(ct));
-
-		return ctBase64;
-	};
-
-	/**
-	 * Symmetrically decrypt a String
-	 * @param ciphertext [String] The base64 encoded ciphertext
-	 * @param nonce [String] The base64 encoded nonce
-	 * @param secretKey [String] The sender's base64 encoded public key
-	 * @return [String] The decrypted plaintext in UTF8
-	 */
-	this.symDecrypt = function(ciphertext, nonce, secretKey) {
-		// convert to Uint8Array
-		var ctBuf = nacl.encode_latin1(util.base642Str(ciphertext));
-		var nonceBuf = nacl.encode_latin1(util.base642Str(nonce));
-		var secretKeyBuf = nacl.encode_latin1(util.base642Str(secretKey));
-		// decrypt
-		var pt = nacl.crypto_secretbox_open(ctBuf, nonceBuf, secretKeyBuf);
-		// decode to string
-		var ptStr = nacl.decode_utf8(pt);
-
-		return ptStr;
-	};
-
 };
 
 if (typeof module !== 'undefined' && module.exports) {
diff --git a/test/unit/nacl-crypto-test.js b/test/unit/nacl-crypto-test.js
index 01b8426..d2d7aa5 100644
--- a/test/unit/nacl-crypto-test.js
+++ b/test/unit/nacl-crypto-test.js
@@ -32,77 +32,34 @@ test("Generate Keypair", 2, function() {
 	nacl_test.recipientKeypair = recipientKeypair;
 });
 
-test("Asymmetric En/Decrypt", 3, function() {
+test("Asymmetric En/Decrypt (Synchronous)", 3, function() {
 	var plaintext = nacl_test.test_message;
 
 	var nonce = nacl_test.crypto.generateNonce();
 	ok(nonce, 'Nonce: ' + nonce);
 	// encrypt
-	var ct = nacl_test.crypto.asymEncrypt(plaintext, nonce, nacl_test.recipientKeypair.boxPk, nacl_test.senderKeypair.boxSk);
+	var ct = nacl_test.crypto.asymEncryptSync(plaintext, nonce, nacl_test.recipientKeypair.boxPk, nacl_test.senderKeypair.boxSk);
 	ok(ct, 'Ciphertext length: ' + ct.length);
 
 	// decrypt
-	var decrypted = nacl_test.crypto.asymDecrypt(ct, nonce, nacl_test.senderKeypair.boxPk, nacl_test.recipientKeypair.boxSk);
+	var decrypted = nacl_test.crypto.asymDecryptSync(ct, nonce, nacl_test.senderKeypair.boxPk, nacl_test.recipientKeypair.boxSk);
 	equal(decrypted, plaintext, 'Decryption correct: ' + decrypted);
 });
 
-test("Symmetric En/Decrypt", 3, function() {
+asyncTest("Asymmetric En/Decrypt (Async/Worker)", 3, function() {
 	var plaintext = nacl_test.test_message;
 
 	var nonce = nacl_test.crypto.generateNonce();
 	ok(nonce, 'Nonce: ' + nonce);
 	// encrypt
-	var ct = nacl_test.crypto.symEncrypt(plaintext, nonce, nacl_test.senderKeypair.boxSk);
-	ok(ct, 'Ciphertext length: ' + ct.length);
+	nacl_test.crypto.asymEncrypt(plaintext, nonce, nacl_test.recipientKeypair.boxPk, nacl_test.senderKeypair.boxSk, function(ct) {
+		ok(ct, 'Ciphertext length: ' + ct.length);
 
-	// decrypt
-	var decrypted = nacl_test.crypto.symDecrypt(ct, nonce, nacl_test.senderKeypair.boxSk);
-	equal(decrypted, plaintext, 'Decryption correct: ' + decrypted);
-});
+		// decrypt
+		nacl_test.crypto.asymDecrypt(ct, nonce, nacl_test.senderKeypair.boxPk, nacl_test.recipientKeypair.boxSk, function(decrypted) {
+			equal(decrypted, plaintext, 'Decryption correct: ' + decrypted);
 
-asyncTest("Asymmetric En/Decrypt (WebWorker)", 3, function() {
-	var plaintext = nacl.encode_utf8(nacl_test.test_message),
-		nonce = nacl.crypto_secretbox_random_nonce(),
-		utl = nacl_test.util,
-		recipientPk = utl.binStr2Uint8Arr(utl.base642Str(nacl_test.recipientKeypair.boxPk)),
-		senderSk = utl.binStr2Uint8Arr(utl.base642Str(nacl_test.senderKeypair.boxSk)),
-		recipienSk = utl.binStr2Uint8Arr(utl.base642Str(nacl_test.recipientKeypair.boxSk)),
-		senderPk = utl.binStr2Uint8Arr(utl.base642Str(nacl_test.senderKeypair.boxPk));
-
-	// encrypt
-
-	function encrypt(pt) {
-		var encryptWorker = new Worker(app.config.workerPath + '/crypto/nacl-worker.js');
-		encryptWorker.onmessage = function(e) {
-			ok(e.data, 'Encryption');
-			decrypt(e.data);
-		};
-		encryptWorker.postMessage({
-			type: 'encrypt',
-			plaintext: pt,
-			nonce: nonce,
-			recipientPk: recipientPk,
-			senderSk: senderSk
-		});
-	}
-
-	// decrypt
-
-	function decrypt(ct) {
-		var decryptWorker = new Worker(app.config.workerPath + '/crypto/nacl-worker.js');
-		decryptWorker.onmessage = function(e) {
-			ok(e.data, 'Decryption');
-			deepEqual(e.data, plaintext, 'Decrypted = Plaintext');
 			start();
-		};
-		decryptWorker.postMessage({
-			type: 'decrypt',
-			ciphertext: ct,
-			nonce: nonce,
-			senderPk: senderPk,
-			recipienSk: recipienSk
 		});
-	}
-
-	encrypt(plaintext);
+	});
 });
\ No newline at end of file