Index: Src/GoogleApis.Auth/GoogleJsonWebSignature.cs
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new file mode 100644
--- /dev/null
+++ b/Src/GoogleApis.Auth/GoogleJsonWebSignature.cs
@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Google.Apis.Auth
+{
+    /// <summary>
+    /// Google JSON Web Signature as specified in https://developers.google.com/accounts/docs/OAuth2ServiceAccount.
+    /// </summary>
+    public class GoogleJsonWebSignature
+    {
+        // TODO(peleyal): We should provide a way to verify JWS.
+        // Take a look at: https://github.com/googleplus/gplus-verifytoken-csharp/blob/master/verifytoken.ashx.cs.
+
+        /// <summary>
+        /// The header as specified in https://developers.google.com/accounts/docs/OAuth2ServiceAccount#formingheader.
+        /// </summary>
+        public class Header : JsonWebSignature.Header
+        {
+        }
+
+        /// <summary>
+        /// The payload as specified in 
+        /// https://developers.google.com/accounts/docs/OAuth2ServiceAccount#formingclaimset.
+        /// </summary>
+        public class Payload : JsonWebSignature.Payload
+        {
+            /// <summary>
+            /// a space-delimited list of the permissions the application requests or <c>null</c>.
+            /// </summary>
+            [Newtonsoft.Json.JsonPropertyAttribute("scope")]
+            public string Scope { get; set; }
+
+            /// <summary>
+            /// The email address of the user for which the application is requesting delegated access.
+            /// </summary>
+            [Newtonsoft.Json.JsonPropertyAttribute("prn")]
+            public string Prn { get; set; }
+        }
+    }
+}