public override void SetUp() { var salt = new byte[] { 104, 12, 112, 82, 85, 10, 11, 61, 15, 54, 44, 66, 117, 89, 64, 110, 53, 123, 33 }; // Prepare PreferenceObfuscator instance sp = Context.GetSharedPreferences(Filename, FileCreationMode.Private); string deviceId = Settings.Secure.GetString(Context.ContentResolver, Settings.Secure.AndroidId); IObfuscator o = new AesObfuscator(salt, Context.PackageName, deviceId); op = new PreferenceObfuscator(sp, o); // Populate with test data op.PutString("testString", "Hello world"); op.Commit(); }