diff --git a/fabric-ca-client/lib/FabricCAClientImpl.js b/fabric-ca-client/lib/FabricCAClientImpl.js
index a94ead8483..dd1c2a9d9b 100644
--- a/fabric-ca-client/lib/FabricCAClientImpl.js
+++ b/fabric-ca-client/lib/FabricCAClientImpl.js
@@ -73,14 +73,35 @@ var FabricCAServices = class {
 
 	/**
 	 * Register the member and return an enrollment secret.
-	 * @param {Object} req Registration request with the following fields: enrollmentID, roles, registrar
-	 * @param {Member} registrar The identity of the registrar (i.e. who is performing the registration)
-	 * @returns Promise for the enrollmentSecret
-	 * @ignore
+	 * @param {Object} req Registration request with the following fields:
+	 * <br> - enrollmentID {string}. ID which will be used for enrollment
+	 * <br> - group {string}. Group to which this user will be assigned, like a company or an organization
+	 * <br> - attrs {{@link KeyValueAttribute}[]}. Array of key/value attributes to assign to the user.
+	 * @param registrar {User}. The identity of the registrar (i.e. who is performing the registration)
+	 * @returns {Promise} The enrollment secret to use when this user enrolls
 	 */
 	register(req, registrar) {
-		var self = this;
+		if (typeof req === 'undefined' || req === null) {
+			throw new Error('Missing required argument "request"');
+		}
 
+		if (typeof req.enrollmentID === 'undefined' || req.enrollmentID === null) {
+			throw new Error('Missing required argument "request.enrollmentID"');
+		}
+
+		if (typeof registrar === 'undefined' || registrar === null) {
+			throw new Error('Missing required argument "registrar"');
+		}
+
+		if (typeof registrar.getName !== 'function') {
+			throw new Error('Argument "registrar" must be an instance of the class "User", but is found to be missing a method "getName()"');
+		}
+
+		if (typeof registrar.getSigningIdentity !== 'function') {
+			throw new Error('Argument "registrar" must be an instance of the class "User", but is found to be missing a method "getSigningIdentity()"');
+		}
+
+		return this._fabricCAClient.register(req.enrollmentID, 'client', req.group, req.attrs, registrar.getName(), registrar.getSigningIdentity());
 	}
 
 	/**
@@ -216,7 +237,6 @@ var FabricCAClient = class {
 	 * @param {string} connect_opts.protocol The protocol to use (either HTTP or HTTPS)
 	 * @param {string} connect_opts.hostname The hostname of the Fabric CA server endpoint
 	 * @param {number} connect_opts.port The port of the Fabric CA server endpoint
-	 * @param {Buffer[]} connect_opts.ca An array of trusted certificates in PEM format
 	 * @throws Will throw an error if connection options are missing or invalid
 	 *
 	 */
@@ -237,7 +257,6 @@ var FabricCAClient = class {
 		} else {
 			this._port = (connect_opts.protocol === 'http' ? 80 : 443);
 		}
-		this._ca = (connect_opts.ca) ? connect_opts.ca : null;
 		this._baseAPI = '/api/v1/cfssl/';
 
 
@@ -256,18 +275,20 @@ var FabricCAClient = class {
 	 * @param {string} group Group to which this user will be assigned
 	 * @param {KeyValueAttribute[]} attrs Array of key/value attributes to assign to the user
 	 * @param {string} callerID The ID of the user who is registering this user
+	 * @param {SigningIdentity} signingIdentity The instance of a SigningIdentity encapsulating the
+	 * signing certificate, hash algorithm and signature algorithm
 	 * @returns {Promise} The enrollment secret to use when this user enrolls
 	 */
-	register(enrollmentID, role, group, attrs, callerID) {
+	register(enrollmentID, role, group, attrs, callerID, signingIdentity) {
 
 		var self = this;
 		var numArgs = arguments.length;
 
 		return new Promise(function (resolve, reject) {
 			//all arguments are required
-			if (numArgs < 5) {
+			if (numArgs < 6) {
 				reject(new Error('Missing required parameters.  \'enrollmentID\', \'role\', \'group\', \'attrs\', \
-					and \'callerID\' are all required.'));
+					\'callerID\' and \'signingIdentity\' are all required.'));
 			}
 
 
@@ -284,8 +305,9 @@ var FabricCAClient = class {
 				port: self._port,
 				path: self._baseAPI + 'register',
 				method: 'POST',
-				//auth: enrollmentID + ':' + enrollmentSecret,
-				ca: self._ca
+				headers: {
+					Authorization: FabricCAClient.generateAuthToken(regRequest, signingIdentity)
+				}
 			};
 
 			var request = self._httpClient.request(requestOptions, function (response) {
@@ -307,8 +329,10 @@ var FabricCAClient = class {
 					try {
 						var regResponse = JSON.parse(payload);
 						if (regResponse.success) {
-							//we want the result field which is Base64-encoded PEM
-							return resolve(regResponse.result);
+							// we want the result field which is Base64-encoded secret.
+							// TODO: Keith said this may be changed soon for 'result' to be the raw secret
+							// without Base64-encoding it
+							return resolve(Buffer.from(regResponse.result, 'base64').toString());
 						} else {
 							return reject(new Error(
 								util.format('Register failed with errors [%s]', JSON.stringify(regResponse.errors))));
@@ -332,13 +356,24 @@ var FabricCAClient = class {
 	}
 
 	/**
-	 * Generate authorization token required for accessing fabric-cop APIs
-	 * @param {string} privKey The pem-encoded private key used for signing
-	 * @param {string} X509Key The pem-encoded X509 certificate associated with privKey
-	 * @param {string} reqBody The body of the request to sign as part of the token
+	 * Generate authorization token required for accessing fabric-ca APIs
 	 */
-	static generateAuthToken(privKey, X509Key, reqBody) {
+	static generateAuthToken(reqBody, signingIdentity) {
+		// sometimes base64 encoding results in trailing one or two "=" as padding
+		var trim = function(string) {
+			return string.replace(/=*$/, '');
+		};
+
+		// specific signing procedure is according to:
+		// https://github.com/hyperledger/fabric-ca/blob/master/util/util.go#L213
+		var cert = trim(Buffer.from(signingIdentity._certificate).toString('base64'));
+		var body = trim(Buffer.from(JSON.stringify(reqBody)).toString('base64'));
+
+		var bodyAndcert = body + '.' + cert;
+		var sig = signingIdentity.sign(bodyAndcert);
 
+		var b64Sign = trim(Buffer.from(sig, 'hex').toString('base64'));
+		return cert + '.' + b64Sign;
 	}
 
 	/**
@@ -366,8 +401,7 @@ var FabricCAClient = class {
 				port: self._port,
 				path: self._baseAPI + 'enroll',
 				method: 'POST',
-				auth: enrollmentID + ':' + enrollmentSecret,
-				ca: self._ca
+				auth: enrollmentID + ':' + enrollmentSecret
 			};
 
 			var enrollRequest = {
diff --git a/test/integration/fabriccopservices-tests.js b/test/integration/fabriccopservices-tests.js
index 8d49d9b923..95d1c8d4df 100644
--- a/test/integration/fabriccopservices-tests.js
+++ b/test/integration/fabriccopservices-tests.js
@@ -28,42 +28,21 @@ var fs = require('fs');
 var path = require('path');
 var testUtil = require('../unit/util.js');
 var utils = require('fabric-client/lib/utils.js');
+var LocalMSP = require('fabric-client/lib/msp/msp.js');
+var idModule = require('fabric-client/lib/msp/identity.js');
+var SigningIdentity = idModule.SigningIdentity;
+var Signer = idModule.Signer;
+var User = require('fabric-client/lib/User.js');
 
 var keyValStorePath = testUtil.KVS;
 
-
 var FabricCAServices = require('fabric-ca-client/lib/FabricCAClientImpl');
 var FabricCAClient = FabricCAServices.FabricCAClient;
 
 var enrollmentID = 'testUser';
-var enrollmentSecret = 'user1';
+var enrollmentSecret;
 var csr = fs.readFileSync(path.resolve(__dirname, '../fixtures/fabriccop/enroll-csr.pem'));
 
-
-test('FabricCAClient: Test enroll With Static CSR', function (t) {
-
-	var client = new FabricCAClient({
-		protocol: 'http',
-		hostname: '127.0.0.1',
-		port: 7054
-	});
-
-	//
-	return client.enroll(enrollmentID, enrollmentSecret, csr.toString())
-		.then(function (pem) {
-			t.comment(pem);
-			t.pass('Successfully invoked enroll API with enrollmentID \'' + enrollmentID + '\'');
-			//check that we got back the expected certificate
-			var cert = new X509();
-			cert.readCertPEM(pem);
-			t.comment(cert.getSubjectString());
-			t.equal(cert.getSubjectString(), '/CN=' + enrollmentID, 'Subject should be /CN=' + enrollmentID);
-		})
-		.catch(function (err) {
-			t.fail('Failed to enroll \'' + enrollmentID + '\'.  ' + err);
-		});
-});
-
 /**
  * FabricCAServices class tests
  */
@@ -83,26 +62,60 @@ test('FabricCAServices: Test enroll() With Dynamic CSR', function (t) {
 		enrollmentSecret: 'adminpw'
 	};
 
+	var eResult, client, member;
 	return cop.enroll(req)
-		.then(
-		function (enrollment) {
-
+		.then((enrollment) => {
 			t.pass('Successfully enrolled \'' + req.enrollmentID + '\'.');
+			eResult = enrollment;
 
 			//check that we got back the expected certificate
 			var cert = new X509();
 			cert.readCertPEM(enrollment.certificate);
 			t.comment(cert.getSubjectString());
 			t.equal(cert.getSubjectString(), '/CN=' + req.enrollmentID, 'Subject should be /CN=' + req.enrollmentID);
-		},
-		function (err) {
-			t.fail('Failed to enroll \'' + req.enrollmentID + '\'.  ' + err);
-		}
-		);
 
+			return cop.cryptoPrimitives.importKey(enrollment.certificate);
+		}).then((pubKey) => {
+			t.pass('Successfully imported public key from the resulting enrollment certificate');
+
+			var msp = new LocalMSP({
+				id: 'DEFAULT',
+				cryptoSuite: cop.cryptoPrimitives
+			});
+
+			var signingIdentity = new SigningIdentity('testSigningIdentity', eResult.certificate, pubKey, msp, new Signer(msp.cryptoSuite, eResult.key));
+
+			return cop._fabricCAClient.register(enrollmentID, 'client', 'bank_a', [], 'admin', signingIdentity);
+		}).then((secret) => {
+			t.comment(secret);
+			enrollmentSecret = secret; // to be used in the next test case
+
+			t.pass('Successfully invoked register API with enrollmentID \'' + enrollmentID + '\'');
+
+			return hfc.newDefaultKeyValueStore({
+				path: testUtil.KVS
+			});
+		}).then((store) => {
+			t.comment('Successfully constructed a state store');
+
+			client = new hfc();
+			client.setStateStore(store);
+			member = new User('adminX', client);
+			return member.setEnrollment(eResult.key, eResult.certificate);
+		}).then(() => {
+			t.comment('Successfully constructed a user object based on the enrollment');
+
+			return cop.register({enrollmentID: 'testUserX', group: 'bank_a'}, member);
+		}).then((secret) => {
+			t.pass('Successfully enrolled "testUserX" in group "bank_a" with enrollment secret returned: ' + secret);
+			t.end();
+		}).catch((err) => {
+			t.fail('Failed at ' + err.stack ? err.stack : err);
+			t.end();
+		});
 });
 
-test('FabricCAClient: Test register', function (t) {
+test('FabricCAClient: Test enroll With Static CSR', function (t) {
 
 	var client = new FabricCAClient({
 		protocol: 'http',
@@ -110,16 +123,20 @@ test('FabricCAClient: Test register', function (t) {
 		port: 7054
 	});
 
-	var enrollmentID = 'testRegisterUser';
-
-
-	return client.register(enrollmentID, 'client', 'bank_a', [], 'admin')
-		.then(function (secret) {
-			t.comment(secret);
-			t.pass('Successfully invoked register API with enrollmentID \'' + enrollmentID + '\'');
-
+	t.comment(util.format('Sending enroll request for user %s with enrollment secret %s', enrollmentID, enrollmentSecret));
+	return client.enroll(enrollmentID, enrollmentSecret, csr.toString())
+		.then(function (pem) {
+			t.comment(pem);
+			t.pass('Successfully invoked enroll API with enrollmentID \'' + enrollmentID + '\'');
+			//check that we got back the expected certificate
+			var cert = new X509();
+			cert.readCertPEM(pem);
+			t.comment(cert.getSubjectString());
+			t.equal(cert.getSubjectString(), '/CN=' + enrollmentID, 'Subject should be /CN=' + enrollmentID);
+			t.end();
 		})
 		.catch(function (err) {
-			t.fail('Failed to register \'' + enrollmentID + '\'.  ' + err);
+			t.fail('Failed to enroll \'' + enrollmentID + '\'.  ' + err);
+			t.end();
 		});
 });
diff --git a/test/unit/fabric-ca-client.js b/test/unit/fabric-ca-client.js
index e7f01a5255..ce6ba76efa 100644
--- a/test/unit/fabric-ca-client.js
+++ b/test/unit/fabric-ca-client.js
@@ -147,6 +147,62 @@ test('FabricCAClient: Test _pemToDer static method',function(t){
 	t.end();
 });
 
+test('FabricCAServices: Test register() function', function(t) {
+	var cop = new FabricCAServices('http://localhost:7054');
+
+	t.throws(
+		() => {
+			cop.register();
+		},
+		/Missing required argument "request"/,
+		'Must fail if missing request argument'
+	);
+	t.throws(
+		() => {
+			cop.register({});
+		},
+		/Missing required argument "request.enrollmentID"/,
+		'Must fail if missing request.enrollmentID argument'
+	);
+	t.throws(
+		() => {
+			cop.register({dummy: 'value'});
+		},
+		/Missing required argument "request.enrollmentID"/,
+		'Must fail if missing request argument'
+	);
+	t.throws(
+		() => {
+			cop.register({enrollmentID: 'testUser'});
+		},
+		/Missing required argument "registrar"/,
+		'Must fail if missing registrar argument'
+	);
+	t.throws(
+		() => {
+			cop.register({enrollmentID: 'testUser'}, {});
+		},
+		/Argument "registrar" must be an instance of the class "User", but is found to be missing a method "getName/,
+		'Must fail if registrar argument is not a User object'
+	);
+	t.throws(
+		() => {
+			cop.register({enrollmentID: 'testUser'}, { getName: function() { return 'dummy';} });
+		},
+		/Argument "registrar" must be an instance of the class "User", but is found to be missing a method "getSigningIdentity/,
+		'Must fail if registrar argument is not a User object'
+	);
+	t.doesNotThrow(
+		() => {
+			cop.register({enrollmentID: 'testUser'}, { getName: function() { return 'dummy'; }, getSigningIdentity: function() { return 'dummy'; } });
+		},
+		null,
+		'Should pass the argument checking but would fail when the register call tries to assemble the auth token'
+	);
+
+	t.end();
+});
+
 test('FabricCAServices: Test _parseURL() function', function (t) {
 
 	var goodHost = 'www.example.com';
@@ -207,6 +263,8 @@ test('FabricCAServices: Test _parseURL() function', function (t) {
 		/InvalidURL: url must start with http or https./,
 		'Throw error for missing protocol'
 	);
+
+	t.end();
 });
 
 /**