diff --git a/common/src/service/IAuthorizationHeaderProvider.cs b/common/src/service/IAuthorizationHeaderProvider.cs
index 207526a168..798ce5bfdb 100644
--- a/common/src/service/IAuthorizationHeaderProvider.cs
+++ b/common/src/service/IAuthorizationHeaderProvider.cs
@@ -3,7 +3,10 @@
 
 namespace Microsoft.Azure.Devices
 {
-    interface IAuthorizationHeaderProvider
+    /// <summary>
+    /// Gets the authorization header for authenticated requests, regardless of choice of authentication.
+    /// </summary>
+    internal interface IAuthorizationHeaderProvider
     {
         string GetAuthorizationHeader();
     }
diff --git a/iothub/service/src/DigitalTwin/Authentication/DigitalTwinConnectionStringCredential.cs b/iothub/service/src/DigitalTwin/Authentication/DigitalTwinConnectionStringCredential.cs
index 03838d7f40..a33d30c151 100644
--- a/iothub/service/src/DigitalTwin/Authentication/DigitalTwinConnectionStringCredential.cs
+++ b/iothub/service/src/DigitalTwin/Authentication/DigitalTwinConnectionStringCredential.cs
@@ -9,7 +9,7 @@ namespace Microsoft.Azure.Devices.Authentication
     /// <summary>
     /// Allows authentication to the API using a Shared Access Key generated from the connection string provided.
     /// The PnP client is auto generated from swagger and needs to implement a specific class to pass to the protocol layer
-    /// unlike the rest of the clients which are hand-written. So, this implementation for authentication is specific to digital twin (Pnp).
+    /// unlike the rest of the clients which are hand-written. So, this implementation for authentication is specific to digital twin (PnP).
     /// </summary>
     internal class DigitalTwinConnectionStringCredential : DigitalTwinServiceClientCredentials
     {
diff --git a/iothub/service/src/DigitalTwin/Authentication/DigitalTwinSasCredential.cs b/iothub/service/src/DigitalTwin/Authentication/DigitalTwinSasCredential.cs
index eb93a2e9ec..02d0a7bd2a 100644
--- a/iothub/service/src/DigitalTwin/Authentication/DigitalTwinSasCredential.cs
+++ b/iothub/service/src/DigitalTwin/Authentication/DigitalTwinSasCredential.cs
@@ -1,8 +1,6 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
-using System;
-using System.Collections.Generic;
-using System.Text;
+
 using Azure;
 using Microsoft.Azure.Devices.Authentication;
 
@@ -11,11 +9,11 @@ namespace Microsoft.Azure.Devices.DigitalTwin.Authentication
     /// <summary>
     /// Allows authentication to the API using a Shared Access Key provided by custom implementation.
     /// The PnP client is auto generated from swagger and needs to implement a specific class to pass to the protocol layer
-    /// unlike the rest of the clients which are hand-written. So, this implementation for authentication is specific to digital twin (Pnp).
+    /// unlike the rest of the clients which are hand-written. So, this implementation for authentication is specific to digital twin (PnP).
     /// </summary>
     internal class DigitalTwinSasCredential : DigitalTwinServiceClientCredentials
     {
-        private AzureSasCredential _credential;
+        private readonly AzureSasCredential _credential;
 
         public DigitalTwinSasCredential(AzureSasCredential credential)
         {
diff --git a/iothub/service/src/DigitalTwin/Authentication/DigitalTwinTokenCredential.cs b/iothub/service/src/DigitalTwin/Authentication/DigitalTwinTokenCredential.cs
index 3b0bc31fe7..51a816e4b4 100644
--- a/iothub/service/src/DigitalTwin/Authentication/DigitalTwinTokenCredential.cs
+++ b/iothub/service/src/DigitalTwin/Authentication/DigitalTwinTokenCredential.cs
@@ -1,8 +1,6 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
-using System;
-using System.Collections.Generic;
-using System.Text;
+
 using System.Threading;
 using Azure.Core;
 using Microsoft.Azure.Devices.Authentication;
@@ -19,7 +17,7 @@ internal class DigitalTwinTokenCredential : DigitalTwinServiceClientCredentials
     {
         private readonly object _tokenLock = new object();
         private AccessToken? _cachedAccessToken;
-        private TokenCredential _credential;
+        private readonly TokenCredential _credential;
 
         public DigitalTwinTokenCredential(TokenCredential credential)
         {
diff --git a/iothub/service/src/IAuthenticationMethod.cs b/iothub/service/src/IAuthenticationMethod.cs
index 67abe5b9b8..5e7930a505 100644
--- a/iothub/service/src/IAuthenticationMethod.cs
+++ b/iothub/service/src/IAuthenticationMethod.cs
@@ -4,7 +4,7 @@
 namespace Microsoft.Azure.Devices
 {
     /// <summary>
-    /// Authentication interface to use for IoTHub communications.
+    /// Authentication interface to use for IoT hub communications.
     /// </summary>
     public interface IAuthenticationMethod
     {
diff --git a/iothub/service/src/IotHubConnectionProperties.cs b/iothub/service/src/IotHubConnectionProperties.cs
index 89162d50c4..f3816297c8 100644
--- a/iothub/service/src/IotHubConnectionProperties.cs
+++ b/iothub/service/src/IotHubConnectionProperties.cs
@@ -1,8 +1,8 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
 using System;
 using System.Collections.Generic;
-using System.Text;
 using System.Threading.Tasks;
 using Microsoft.Azure.Amqp;
 using Microsoft.Azure.Devices.Common;
diff --git a/iothub/service/src/IotHubSasCredentialProperties.cs b/iothub/service/src/IotHubSasCredentialProperties.cs
index 0af2131065..933f400cd1 100644
--- a/iothub/service/src/IotHubSasCredentialProperties.cs
+++ b/iothub/service/src/IotHubSasCredentialProperties.cs
@@ -1,17 +1,16 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
 using System;
-using System.Collections.Generic;
-using System.Text;
 using System.Threading.Tasks;
 using Microsoft.Azure.Amqp;
-using System.Globalization;
-using System.Linq;
-using Microsoft.Azure.Devices.Common.Data;
 
 #if !NET451
 
+using System.Collections.Generic;
+using System.Linq;
 using Azure;
+using Microsoft.Azure.Devices.Common.Data;
 
 #endif
 
diff --git a/iothub/service/src/IotHubTokenCredentialProperties.cs b/iothub/service/src/IotHubTokenCredentialProperties.cs
index 3591a66038..1efa16ecf2 100644
--- a/iothub/service/src/IotHubTokenCredentialProperties.cs
+++ b/iothub/service/src/IotHubTokenCredentialProperties.cs
@@ -1,16 +1,15 @@
 // Copyright (c) Microsoft. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
 using System;
-using System.Collections.Generic;
-using System.Text;
 using System.Threading.Tasks;
 using Microsoft.Azure.Amqp;
-using System.Threading;
-using Microsoft.Azure.Devices.Common;
 
 #if !NET451
 
+using System.Threading;
 using Azure.Core;
+using Microsoft.Azure.Devices.Common;
 
 #endif
 
@@ -23,7 +22,7 @@ internal class IotHubTokenCrendentialProperties
         : IotHubConnectionProperties
     {
 #if !NET451
-        private const string _tokenType = "Bearer";
+        private const string TokenType = "Bearer";
         private readonly TokenCredential _credential;
         private readonly object _tokenLock = new object();
         private AccessToken? _cachedAccessToken;
@@ -63,8 +62,7 @@ public override string GetAuthorizationHeader()
                 }
             }
 
-            return $"{_tokenType} {_cachedAccessToken.Value.Token}";
-
+            return $"{TokenType} {_cachedAccessToken.Value.Token}";
 #endif
         }
 
@@ -82,8 +80,8 @@ public async override Task<CbsToken> GetTokenAsync(Uri namespaceAddress, string
                 new TokenRequestContext(CommonConstants.IotHubAadTokenScopes),
                 new CancellationToken()).ConfigureAwait(false);
             return new CbsToken(
-               $"{_tokenType} {token.Token}",
-                _tokenType,
+               $"{TokenType} {token.Token}",
+                TokenType,
                 token.ExpiresOn.UtcDateTime);
 #endif
         }
diff --git a/iothub/service/src/ServiceAuthenticationWithDeviceSharedAccessPolicyKey.cs b/iothub/service/src/ServiceAuthenticationWithDeviceSharedAccessPolicyKey.cs
index 21bf338279..24d778c146 100644
--- a/iothub/service/src/ServiceAuthenticationWithDeviceSharedAccessPolicyKey.cs
+++ b/iothub/service/src/ServiceAuthenticationWithDeviceSharedAccessPolicyKey.cs
@@ -21,6 +21,16 @@ public ServiceAuthenticationWithDeviceSharedAccessPolicyKey(string deviceId, str
             Key = sharedAccessKey;
         }
 
+        /// <summary>
+        /// Shared access key of the device
+        /// </summary>
+        public string Key { get; set; }
+
+        /// <summary>
+        /// Name of device
+        /// </summary>
+        public string DeviceId { get; set; }
+
         /// <summary>
         /// Populates the builder with values needed to authenticate with device's shared access key.
         /// </summary>
@@ -33,21 +43,11 @@ public IotHubConnectionStringBuilder Populate(IotHubConnectionStringBuilder iotH
                 throw new ArgumentNullException(nameof(iotHubConnectionStringBuilder));
             }
 
-            iotHubConnectionStringBuilder.SharedAccessKey = this.Key;
-            iotHubConnectionStringBuilder.DeviceId = this.DeviceId;
+            iotHubConnectionStringBuilder.SharedAccessKey = Key;
+            iotHubConnectionStringBuilder.DeviceId = DeviceId;
             iotHubConnectionStringBuilder.SharedAccessSignature = null;
 
             return iotHubConnectionStringBuilder;
         }
-
-        /// <summary>
-        /// Shared access key of the device
-        /// </summary>
-        public string Key { get; set; }
-
-        /// <summary>
-        /// Name of device
-        /// </summary>
-        public string DeviceId { get; set; }
     }
 }
diff --git a/iothub/service/src/ServiceAuthenticationWithDeviceSharedAccessPolicyToken.cs b/iothub/service/src/ServiceAuthenticationWithDeviceSharedAccessPolicyToken.cs
index 0d207fc9c6..d49772bb77 100644
--- a/iothub/service/src/ServiceAuthenticationWithDeviceSharedAccessPolicyToken.cs
+++ b/iothub/service/src/ServiceAuthenticationWithDeviceSharedAccessPolicyToken.cs
@@ -21,6 +21,16 @@ public ServiceAuthenticationWithDeviceSharedAccessPolicyToken(string deviceId, s
             Token = sharedAccessSignature;
         }
 
+        /// <summary>
+        /// Name of device
+        /// </summary>
+        public string DeviceId { get; set; }
+
+        /// <summary>
+        /// Shared access signature generated using device's shared access key
+        /// </summary>
+        public string Token { get; set; }
+
         /// <summary>
         /// Populates the builder with values needed to authenticate with device's shared access signature.
         /// </summary>
@@ -34,20 +44,10 @@ public IotHubConnectionStringBuilder Populate(IotHubConnectionStringBuilder iotH
             }
 
             iotHubConnectionStringBuilder.SharedAccessKey = null;
-            iotHubConnectionStringBuilder.DeviceId = this.DeviceId;
-            iotHubConnectionStringBuilder.SharedAccessSignature = this.Token;
+            iotHubConnectionStringBuilder.DeviceId = DeviceId;
+            iotHubConnectionStringBuilder.SharedAccessSignature = Token;
 
             return iotHubConnectionStringBuilder;
         }
-
-        /// <summary>
-        /// Name of device
-        /// </summary>
-        public string DeviceId { get; set; }
-
-        /// <summary>
-        /// Shared access signature generated using device's shared access key
-        /// </summary>
-        public string Token { get; set; }
     }
 }
diff --git a/iothub/service/src/ServiceAuthenticationWithSharedAccessPolicyKey.cs b/iothub/service/src/ServiceAuthenticationWithSharedAccessPolicyKey.cs
index c30cfda7f8..b6bd3c6887 100644
--- a/iothub/service/src/ServiceAuthenticationWithSharedAccessPolicyKey.cs
+++ b/iothub/service/src/ServiceAuthenticationWithSharedAccessPolicyKey.cs
@@ -31,7 +31,7 @@ public ServiceAuthenticationWithSharedAccessPolicyKey(string policyName, string
         public string PolicyName
         {
             get => _policyName;
-            set { SetPolicyName(value); }
+            set => SetPolicyName(value);
         }
 
         /// <summary>