diff --git a/xcode/OLMKit.xcodeproj/project.pbxproj b/xcode/OLMKit.xcodeproj/project.pbxproj
index b50341b..fa02539 100644
--- a/xcode/OLMKit.xcodeproj/project.pbxproj
+++ b/xcode/OLMKit.xcodeproj/project.pbxproj
@@ -10,6 +10,7 @@
 		3274F6021D9A633A005282E4 /* OLMKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 3274F5F81D9A633A005282E4 /* OLMKit.framework */; };
 		3274F6071D9A633A005282E4 /* OLMKitTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 3274F6061D9A633A005282E4 /* OLMKitTests.m */; };
 		3274F6131D9A698E005282E4 /* OLMKit.h in Headers */ = {isa = PBXBuildFile; fileRef = 3274F6121D9A698E005282E4 /* OLMKit.h */; };
+		32A151311DABDD4300400192 /* OLMKitGroupTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 32A151301DABDD4300400192 /* OLMKitGroupTests.m */; };
 		7DBAD311AEA85CF6DB80DCFA /* libPods-OLMKitTests.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 7123FABE917D0FB140E036B7 /* libPods-OLMKitTests.a */; };
 		D667051A0BA47E17CCC4E5D7 /* libPods-OLMKit.a in Frameworks */ = {isa = PBXBuildFile; fileRef = F2F22FE8F173AF845B882805 /* libPods-OLMKit.a */; };
 /* End PBXBuildFile section */
@@ -32,6 +33,7 @@
 		3274F6061D9A633A005282E4 /* OLMKitTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = OLMKitTests.m; sourceTree = "<group>"; };
 		3274F6081D9A633A005282E4 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		3274F6121D9A698E005282E4 /* OLMKit.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = OLMKit.h; sourceTree = "<group>"; };
+		32A151301DABDD4300400192 /* OLMKitGroupTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = OLMKitGroupTests.m; sourceTree = "<group>"; };
 		7123FABE917D0FB140E036B7 /* libPods-OLMKitTests.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-OLMKitTests.a"; sourceTree = BUILT_PRODUCTS_DIR; };
 		875BA7A520258EA15A31DD82 /* Pods-OLMKitTests.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-OLMKitTests.debug.xcconfig"; path = "Pods/Target Support Files/Pods-OLMKitTests/Pods-OLMKitTests.debug.xcconfig"; sourceTree = "<group>"; };
 		D48E486DAE1F59F4F7EA8C25 /* Pods-OLMKitTests.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-OLMKitTests.release.xcconfig"; path = "Pods/Target Support Files/Pods-OLMKitTests/Pods-OLMKitTests.release.xcconfig"; sourceTree = "<group>"; };
@@ -104,6 +106,7 @@
 			isa = PBXGroup;
 			children = (
 				3274F6061D9A633A005282E4 /* OLMKitTests.m */,
+				32A151301DABDD4300400192 /* OLMKitGroupTests.m */,
 				3274F6081D9A633A005282E4 /* Info.plist */,
 			);
 			path = OLMKitTests;
@@ -318,6 +321,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				3274F6071D9A633A005282E4 /* OLMKitTests.m in Sources */,
+				32A151311DABDD4300400192 /* OLMKitGroupTests.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
diff --git a/xcode/OLMKitTests/OLMKitGroupTests.m b/xcode/OLMKitTests/OLMKitGroupTests.m
index bcf83ef..9f5ad10 100644
--- a/xcode/OLMKitTests/OLMKitGroupTests.m
+++ b/xcode/OLMKitTests/OLMKitGroupTests.m
@@ -1,13 +1,25 @@
-//
-//  OLMKitGroupTests.m
-//  OLMKit
-//
-//  Created by Emmanuel ROHEE on 10/10/16.
-//  Copyright © 2016 matrix.org. All rights reserved.
-//
+/*
+ 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.
+ */
 
 #import <XCTest/XCTest.h>
 
+#import <OLMKit/OLMKit.h>
+
+#include "olm/olm.h"
+
 @interface OLMKitGroupTests : XCTestCase
 
 @end
@@ -24,16 +36,50 @@
     [super tearDown];
 }
 
-- (void)testExample {
-    // This is an example of a functional test case.
-    // Use XCTAssert and related functions to verify your tests produce the correct results.
+- (void)testAliceAndBob {
+
+    OLMOutboundGroupSession *aliceSession = [[OLMOutboundGroupSession alloc] initOutboundGroupSession];
+    XCTAssertGreaterThan(aliceSession.sessionIdentifier.length, 0);
+    XCTAssertGreaterThan(aliceSession.sessionKey.length, 0);
+    XCTAssertEqual(aliceSession.messageIndex, 0);
+
+    // Store the session key before starting encrypting
+    NSString *sessionKey = aliceSession.sessionKey;
+
+    NSString *message = @"Hello!";
+    NSString *aliceToBobMsg = [aliceSession encryptMessage:message];
+
+    XCTAssertEqual(aliceSession.messageIndex, 1);
+    XCTAssertGreaterThanOrEqual(aliceToBobMsg.length, 0);
+
+    OLMInboundGroupSession *bobSession = [[OLMInboundGroupSession alloc] initInboundGroupSessionWithSessionKey:sessionKey];
+    XCTAssertEqualObjects(aliceSession.sessionIdentifier, bobSession.sessionIdentifier);
+
+    NSString *plaintext = [bobSession decryptMessage:aliceToBobMsg];
+    XCTAssertEqualObjects(message, plaintext);
 }
 
-- (void)testPerformanceExample {
-    // This is an example of a performance test case.
-    [self measureBlock:^{
-        // Put the code you want to measure the time of here.
-    }];
+- (void)testOutboundGroupSessionSerialization {
+
+    OLMOutboundGroupSession *aliceSession = [[OLMOutboundGroupSession alloc] initOutboundGroupSession];
+
+    NSData *aliceData = [NSKeyedArchiver archivedDataWithRootObject:aliceSession];
+    OLMOutboundGroupSession *aliceSession2 = [NSKeyedUnarchiver unarchiveObjectWithData:aliceData];
+
+    XCTAssertEqualObjects(aliceSession2.sessionKey, aliceSession.sessionKey);
+    XCTAssertEqualObjects(aliceSession2.sessionIdentifier, aliceSession.sessionIdentifier);
+}
+
+- (void)testInboundGroupSessionSerialization {
+
+    OLMOutboundGroupSession *aliceSession = [[OLMOutboundGroupSession alloc] initOutboundGroupSession];
+
+    OLMInboundGroupSession *bobSession = [[OLMInboundGroupSession alloc] initInboundGroupSessionWithSessionKey:aliceSession.sessionKey];
+
+    NSData *bobData = [NSKeyedArchiver archivedDataWithRootObject:bobSession];
+    OLMInboundGroupSession *bobSession2 = [NSKeyedUnarchiver unarchiveObjectWithData:bobData];
+
+    XCTAssertEqualObjects(bobSession2.sessionIdentifier, aliceSession.sessionIdentifier);
 }
 
 @end