diff --git a/src/Microsoft.AspNet.Http.Interfaces/Authentication/AuthenticateContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/AuthenticateContext.cs
new file mode 100644
index 0000000000..e76a501d73
--- /dev/null
+++ b/src/Microsoft.AspNet.Http.Interfaces/Authentication/AuthenticateContext.cs
@@ -0,0 +1,40 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using System.Security.Claims;
+using Microsoft.Framework.Internal;
+
+namespace Microsoft.AspNet.Http.Authentication
+{
+    public class AuthenticateContext
+    {
+        public AuthenticateContext([NotNull] string authenticationScheme)
+        {
+            AuthenticationScheme = authenticationScheme;
+        }
+
+        public string AuthenticationScheme { get; }
+
+        public bool Accepted { get; private set; }
+
+        public ClaimsPrincipal Principal { get; private set; }
+
+        public IDictionary<string, string> Properties { get; private set; }
+
+        public IDictionary<string, object> Description { get; private set; }
+
+        public virtual void Authenticated(ClaimsPrincipal principal, IDictionary<string, string> properties, IDictionary<string, object> description)
+        {
+            Accepted = true;
+            Principal = principal;
+            Properties = properties;
+            Description = description;
+        }
+
+        public virtual void NotAuthenticated()
+        {
+            Accepted = true;
+        }
+    }
+}
diff --git a/src/Microsoft.AspNet.Http/Authentication/ChallengeContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/ChallengeContext.cs
similarity index 54%
rename from src/Microsoft.AspNet.Http/Authentication/ChallengeContext.cs
rename to src/Microsoft.AspNet.Http.Interfaces/Authentication/ChallengeContext.cs
index 0a137bb645..e1b6bf8c04 100644
--- a/src/Microsoft.AspNet.Http/Authentication/ChallengeContext.cs
+++ b/src/Microsoft.AspNet.Http.Interfaces/Authentication/ChallengeContext.cs
@@ -3,35 +3,26 @@
 
 using System;
 using System.Collections.Generic;
-using Microsoft.Framework.Internal;
 
 namespace Microsoft.AspNet.Http.Authentication
 {
-    public class ChallengeContext : IChallengeContext
+    public class ChallengeContext
     {
-        private bool _accepted;
-
         public ChallengeContext(string authenticationScheme, IDictionary<string, string> properties)
         {
             AuthenticationScheme = authenticationScheme;
             Properties = properties ?? new Dictionary<string, string>(StringComparer.Ordinal);
-
-            // The default Challenge with no scheme is always accepted
-            _accepted = string.IsNullOrEmpty(authenticationScheme);
         }
 
-        public string AuthenticationScheme { get; private set; }
+        public string AuthenticationScheme { get; }
 
-        public IDictionary<string, string> Properties { get; private set; }
+        public IDictionary<string, string> Properties { get; }
 
-        public bool Accepted
-        {
-            get { return _accepted; }
-        }
+        public bool Accepted { get; private set; }
 
         public void Accept()
         {
-            _accepted = true;
+            Accepted = true;
         }
     }
-}
+}
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Http/Authentication/DescribeSchemesContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/DescribeSchemesContext.cs
similarity index 60%
rename from src/Microsoft.AspNet.Http/Authentication/DescribeSchemesContext.cs
rename to src/Microsoft.AspNet.Http.Interfaces/Authentication/DescribeSchemesContext.cs
index 6e4907949d..38daa0a856 100644
--- a/src/Microsoft.AspNet.Http/Authentication/DescribeSchemesContext.cs
+++ b/src/Microsoft.AspNet.Http.Interfaces/Authentication/DescribeSchemesContext.cs
@@ -5,23 +5,23 @@ using System.Collections.Generic;
 
 namespace Microsoft.AspNet.Http.Authentication
 {
-    public class DescribeSchemesContext : IDescribeSchemesContext
+    public class DescribeSchemesContext
     {
-        private List<AuthenticationDescription> _results;
+        private List<IDictionary<string, object>> _results;
 
         public DescribeSchemesContext()
         {
-            _results = new List<AuthenticationDescription>();
+            _results = new List<IDictionary<string, object>>();
         }
 
-        public IEnumerable<AuthenticationDescription> Results
+        public IEnumerable<IDictionary<string, object>> Results
         {
             get { return _results; }
         }
 
         public void Accept(IDictionary<string, object> description)
         {
-            _results.Add(new AuthenticationDescription(description));
+            _results.Add(description);
         }
     }
-}
+}
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Http.Interfaces/Authentication/IAuthenticateContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/IAuthenticateContext.cs
deleted file mode 100644
index ecf8b56788..0000000000
--- a/src/Microsoft.AspNet.Http.Interfaces/Authentication/IAuthenticateContext.cs
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Collections.Generic;
-using System.Security.Claims;
-
-namespace Microsoft.AspNet.Http.Authentication
-{
-    public interface IAuthenticateContext
-    {
-        string AuthenticationScheme { get; }
-
-        void Authenticated(ClaimsPrincipal principal, IDictionary<string, string> properties, IDictionary<string, object> description);
-
-        void NotAuthenticated();
-    }
-}
diff --git a/src/Microsoft.AspNet.Http.Interfaces/Authentication/IAuthenticationHandler.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/IAuthenticationHandler.cs
index 76b3e8cb1b..04a7039a80 100644
--- a/src/Microsoft.AspNet.Http.Interfaces/Authentication/IAuthenticationHandler.cs
+++ b/src/Microsoft.AspNet.Http.Interfaces/Authentication/IAuthenticationHandler.cs
@@ -7,13 +7,16 @@ namespace Microsoft.AspNet.Http.Authentication
 {
     public interface IAuthenticationHandler
     {
-        void GetDescriptions(IDescribeSchemesContext context);
+        void GetDescriptions(DescribeSchemesContext context);
 
-        void Authenticate(IAuthenticateContext context);
-        Task AuthenticateAsync(IAuthenticateContext context);
+        void Authenticate(AuthenticateContext context);
 
-        void Challenge(IChallengeContext context);
-        void SignIn(ISignInContext context);
-        void SignOut(ISignOutContext context);
+        Task AuthenticateAsync(AuthenticateContext context);
+
+        void Challenge(ChallengeContext context);
+
+        void SignIn(SignInContext context);
+
+        void SignOut(SignOutContext context);
     }
 }
diff --git a/src/Microsoft.AspNet.Http.Interfaces/Authentication/IChallengeContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/IChallengeContext.cs
deleted file mode 100644
index 26a90fefb2..0000000000
--- a/src/Microsoft.AspNet.Http.Interfaces/Authentication/IChallengeContext.cs
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Collections.Generic;
-
-namespace Microsoft.AspNet.Http.Authentication
-{
-    public interface IChallengeContext
-    {
-        string AuthenticationScheme { get; }
-        IDictionary<string, string> Properties { get; }
-
-        void Accept();
-    }
-}
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Http.Interfaces/Authentication/IDescribeSchemesContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/IDescribeSchemesContext.cs
deleted file mode 100644
index 96f395cb37..0000000000
--- a/src/Microsoft.AspNet.Http.Interfaces/Authentication/IDescribeSchemesContext.cs
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Collections.Generic;
-
-namespace Microsoft.AspNet.Http.Authentication
-{
-    public interface IDescribeSchemesContext
-    {
-        void Accept(IDictionary<string,object> description);
-    }
-}
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Http.Interfaces/Authentication/ISignInContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/ISignInContext.cs
deleted file mode 100644
index c79860279d..0000000000
--- a/src/Microsoft.AspNet.Http.Interfaces/Authentication/ISignInContext.cs
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Collections.Generic;
-using System.Security.Claims;
-
-namespace Microsoft.AspNet.Http.Authentication
-{
-    public interface ISignInContext
-    {
-        //IEnumerable<ClaimsPrincipal> Principals { get; }
-        ClaimsPrincipal Principal { get; }
-        IDictionary<string, string> Properties { get; }
-        string AuthenticationScheme { get; }
-
-        void Accept(IDictionary<string, object> description);
-    }
-}
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Http.Interfaces/Authentication/ISignOutContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/ISignOutContext.cs
deleted file mode 100644
index 2bb7036026..0000000000
--- a/src/Microsoft.AspNet.Http.Interfaces/Authentication/ISignOutContext.cs
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Collections.Generic;
-
-namespace Microsoft.AspNet.Http.Authentication
-{
-    public interface ISignOutContext 
-    {
-        string AuthenticationScheme { get; }
-
-        IDictionary<string, string> Properties { get; }
-
-        void Accept();
-    }
-}
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Http/Authentication/SignInContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/SignInContext.cs
similarity index 70%
rename from src/Microsoft.AspNet.Http/Authentication/SignInContext.cs
rename to src/Microsoft.AspNet.Http.Interfaces/Authentication/SignInContext.cs
index 1a77db412b..d5d74c3186 100644
--- a/src/Microsoft.AspNet.Http/Authentication/SignInContext.cs
+++ b/src/Microsoft.AspNet.Http.Interfaces/Authentication/SignInContext.cs
@@ -8,31 +8,26 @@ using Microsoft.Framework.Internal;
 
 namespace Microsoft.AspNet.Http.Authentication
 {
-    public class SignInContext : ISignInContext
+    public class SignInContext
     {
-        private bool _accepted;
-
-        public SignInContext([NotNull] string authenticationScheme, [NotNull] ClaimsPrincipal principal, IDictionary<string, string> dictionary)
+        public SignInContext([NotNull] string authenticationScheme, [NotNull] ClaimsPrincipal principal, IDictionary<string, string> properties)
         {
             AuthenticationScheme = authenticationScheme;
             Principal = principal;
-            Properties = dictionary ?? new Dictionary<string, string>(StringComparer.Ordinal);
+            Properties = properties ?? new Dictionary<string, string>(StringComparer.Ordinal);
         }
 
+        public string AuthenticationScheme { get; }
+
         public ClaimsPrincipal Principal { get; }
 
         public IDictionary<string, string> Properties { get; }
 
-        public string AuthenticationScheme { get; }
+        public bool Accepted { get; private set; }
 
-        public bool Accepted
+        public void Accept()
         {
-            get { return _accepted; }
-        }
-
-        public void Accept(IDictionary<string, object> description)
-        {
-            _accepted = true;
+            Accepted = true;
         }
     }
 }
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Http/Authentication/SignOutContext.cs b/src/Microsoft.AspNet.Http.Interfaces/Authentication/SignOutContext.cs
similarity index 79%
rename from src/Microsoft.AspNet.Http/Authentication/SignOutContext.cs
rename to src/Microsoft.AspNet.Http.Interfaces/Authentication/SignOutContext.cs
index d78820980e..27a7d2941b 100644
--- a/src/Microsoft.AspNet.Http/Authentication/SignOutContext.cs
+++ b/src/Microsoft.AspNet.Http.Interfaces/Authentication/SignOutContext.cs
@@ -7,10 +7,8 @@ using Microsoft.Framework.Internal;
 
 namespace Microsoft.AspNet.Http.Authentication
 {
-    public class SignOutContext : ISignOutContext
+    public class SignOutContext
     {
-        private bool _accepted;
-
         public SignOutContext([NotNull] string authenticationScheme, IDictionary<string, string> properties)
         {
             AuthenticationScheme = authenticationScheme;
@@ -21,14 +19,11 @@ namespace Microsoft.AspNet.Http.Authentication
 
         public IDictionary<string, string> Properties { get; }
 
-        public bool Accepted
-        {
-            get { return _accepted; }
-        }
+        public bool Accepted { get; private set; }
 
         public void Accept()
         {
-            _accepted = true;
+            Accepted = true;
         }
     }
-}
+}
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Http.Interfaces/project.json b/src/Microsoft.AspNet.Http.Interfaces/project.json
index 3af7b3bdfb..d4d113923c 100644
--- a/src/Microsoft.AspNet.Http.Interfaces/project.json
+++ b/src/Microsoft.AspNet.Http.Interfaces/project.json
@@ -1,16 +1,21 @@
 {
-  "version": "1.0.0-*",
-  "description": "ASP.NET 5 HTTP feature interface definitions.",
-  "frameworks": {
-    "dnx451": {},
-    "dnxcore50": {
-      "dependencies": {
-        "System.Net.Primitives": "4.0.10-beta-*",
-        "System.Net.WebSockets" : "4.0.0-beta-*",
-        "System.Security.Claims": "4.0.0-beta-*",
-        "System.Security.Cryptography.X509Certificates": "4.0.0-beta-*",
-        "System.Security.Principal": "4.0.0-beta-*"
-      }
+    "version": "1.0.0-*",
+    "description": "ASP.NET 5 HTTP feature interface definitions.",
+    "dependencies": {
+        "Microsoft.Framework.NotNullAttribute.Internal": { "type": "build", "version": "1.0.0-*" }
+    },
+    "frameworks": {
+        "dnx451": { },
+        "dnxcore50": {
+            "dependencies": {
+                "System.Collections": "4.0.10-beta-*",
+                "System.Net.Primitives": "4.0.10-beta-*",
+                "System.Net.WebSockets": "4.0.0-beta-*",
+                "System.Runtime.Extensions": "4.0.10-beta-*",
+                "System.Security.Claims": "4.0.0-beta-*",
+                "System.Security.Cryptography.X509Certificates": "4.0.0-beta-*",
+                "System.Security.Principal": "4.0.0-beta-*"
+            }
+        }
     }
-  }
 }
diff --git a/src/Microsoft.AspNet.Http/Authentication/AuthenticateContext.cs b/src/Microsoft.AspNet.Http/Authentication/AuthenticateContext.cs
deleted file mode 100644
index 91d530dfad..0000000000
--- a/src/Microsoft.AspNet.Http/Authentication/AuthenticateContext.cs
+++ /dev/null
@@ -1,41 +0,0 @@
-// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
-// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
-
-using System.Collections.Generic;
-using System.Security.Claims;
-using Microsoft.Framework.Internal;
-
-namespace Microsoft.AspNet.Http.Authentication
-{
-    public class AuthenticateContext : IAuthenticateContext
-    {
-        private AuthenticationResult _result;
-        private bool _accepted;
-
-        public AuthenticateContext([NotNull] string authenticationScheme)
-        {
-            AuthenticationScheme = authenticationScheme;
-        }
-
-        public string AuthenticationScheme { get; private set; }
-
-        public AuthenticationResult Result { get; set; }
-
-        public bool Accepted
-        {
-            get { return _accepted; }
-        }
-
-        public void Authenticated(ClaimsPrincipal principal, IDictionary<string, string> properties, IDictionary<string, object> description)
-        {
-            var descrip = new AuthenticationDescription(description);
-            _accepted = true;
-            Result = new AuthenticationResult(principal, new AuthenticationProperties(properties), descrip);
-        }
-
-        public void NotAuthenticated()
-        {
-            _accepted = true;
-        }
-    }
-}
diff --git a/src/Microsoft.AspNet.Http/Authentication/DefaultAuthenticationManager.cs b/src/Microsoft.AspNet.Http/Authentication/DefaultAuthenticationManager.cs
index 9fccca6116..e21bea9634 100644
--- a/src/Microsoft.AspNet.Http/Authentication/DefaultAuthenticationManager.cs
+++ b/src/Microsoft.AspNet.Http/Authentication/DefaultAuthenticationManager.cs
@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Security.Claims;
 using System.Threading.Tasks;
 using Microsoft.AspNet.FeatureModel;
@@ -42,7 +43,7 @@ namespace Microsoft.AspNet.Http.Authentication
 
             var describeContext = new DescribeSchemesContext();
             handler.GetDescriptions(describeContext);
-            return describeContext.Results;
+            return describeContext.Results.Select(description => new AuthenticationDescription(description));
         }
 
         public override AuthenticationResult Authenticate([NotNull] string authenticationScheme)
@@ -57,10 +58,12 @@ namespace Microsoft.AspNet.Http.Authentication
 
             if (!authenticateContext.Accepted)
             {
-                throw new InvalidOperationException("The following authentication scheme was not accepted: " + authenticationScheme);
+                throw new InvalidOperationException($"The following authentication scheme was not accepted: {authenticationScheme}");
             }
 
-            return authenticateContext.Result;
+            return new AuthenticationResult(authenticateContext.Principal,
+                new AuthenticationProperties(authenticateContext.Properties),
+                new AuthenticationDescription(authenticateContext.Description));
         }
 
         public override async Task<AuthenticationResult> AuthenticateAsync([NotNull] string authenticationScheme)
@@ -76,10 +79,12 @@ namespace Microsoft.AspNet.Http.Authentication
             // Verify all types ack'd
             if (!authenticateContext.Accepted)
             {
-                throw new InvalidOperationException("The following authentication scheme was not accepted: " + authenticationScheme);
+                throw new InvalidOperationException($"The following authentication scheme was not accepted: {authenticationScheme}");
             }
 
-            return authenticateContext.Result;
+            return new AuthenticationResult(authenticateContext.Principal,
+                new AuthenticationProperties(authenticateContext.Properties),
+                new AuthenticationDescription(authenticateContext.Description));
         }
 
         public override void Challenge(AuthenticationProperties properties, string authenticationScheme)
@@ -87,23 +92,24 @@ namespace Microsoft.AspNet.Http.Authentication
             HttpResponseFeature.StatusCode = 401;
             var handler = HttpAuthenticationFeature.Handler;
 
-            var challengeContext = new ChallengeContext(authenticationScheme, properties == null ? null : properties.Items);
+            var challengeContext = new ChallengeContext(authenticationScheme, properties?.Items);
             if (handler != null)
             {
                 handler.Challenge(challengeContext);
             }
 
-            if (!challengeContext.Accepted)
+            // The default Challenge with no scheme is always accepted
+            if (!challengeContext.Accepted && !string.IsNullOrEmpty(authenticationScheme))
             {
-                throw new InvalidOperationException("The following authentication type was not accepted: " + authenticationScheme);
+                throw new InvalidOperationException($"The following authentication scheme was not accepted: {authenticationScheme}");
             }
         }
 
-        public override void SignIn(string authenticationScheme, [NotNull] ClaimsPrincipal principal, AuthenticationProperties properties)
+        public override void SignIn([NotNull] string authenticationScheme, [NotNull] ClaimsPrincipal principal, AuthenticationProperties properties)
         {
             var handler = HttpAuthenticationFeature.Handler;
 
-            var signInContext = new SignInContext(authenticationScheme, principal, properties == null ? null : properties.Items);
+            var signInContext = new SignInContext(authenticationScheme, principal, properties?.Items);
             if (handler != null)
             {
                 handler.SignIn(signInContext);
@@ -112,7 +118,7 @@ namespace Microsoft.AspNet.Http.Authentication
             // Verify all types ack'd
             if (!signInContext.Accepted)
             {
-                throw new InvalidOperationException("The following authentication scheme was not accepted: " + authenticationScheme);
+                throw new InvalidOperationException($"The following authentication scheme was not accepted: {authenticationScheme}");
             }
         }
 
@@ -129,7 +135,7 @@ namespace Microsoft.AspNet.Http.Authentication
             // Verify all types ack'd
             if (!string.IsNullOrWhiteSpace(authenticationScheme) && !signOutContext.Accepted)
             {
-                throw new InvalidOperationException("The following authentication scheme was not accepted: " + authenticationScheme);
+                throw new InvalidOperationException($"The following authentication scheme was not accepted: {authenticationScheme}");
             }
         }
 
diff --git a/test/Microsoft.AspNet.Http.Tests/DefaultHttpContextTests.cs b/test/Microsoft.AspNet.Http.Tests/DefaultHttpContextTests.cs
index c53c3c73c2..ea887b711b 100644
--- a/test/Microsoft.AspNet.Http.Tests/DefaultHttpContextTests.cs
+++ b/test/Microsoft.AspNet.Http.Tests/DefaultHttpContextTests.cs
@@ -97,33 +97,33 @@ namespace Microsoft.AspNet.Http
         {
             public bool SignedIn { get; set; }
 
-            public void Authenticate(IAuthenticateContext context)
+            public void Authenticate(AuthenticateContext context)
             {
                 throw new NotImplementedException();
             }
 
-            public Task AuthenticateAsync(IAuthenticateContext context)
+            public Task AuthenticateAsync(AuthenticateContext context)
             {
                 throw new NotImplementedException();
             }
 
-            public void Challenge(IChallengeContext context)
+            public void Challenge(ChallengeContext context)
             {
                 throw new NotImplementedException();
             }
 
-            public void GetDescriptions(IDescribeSchemesContext context)
+            public void GetDescriptions(DescribeSchemesContext context)
             {
                 throw new NotImplementedException();
             }
 
-            public void SignIn(ISignInContext context)
+            public void SignIn(SignInContext context)
             {
                 SignedIn = true;
-                context.Accept(new Dictionary<string, object>());
+                context.Accept();
             }
 
-            public void SignOut(ISignOutContext context)
+            public void SignOut(SignOutContext context)
             {
                 SignedIn = false;
                 context.Accept();