diff --git a/src/Core/Identity/U2fTokenProvider.cs b/src/Core/Identity/U2fTokenProvider.cs
index a49086dcbe..340a32041f 100644
--- a/src/Core/Identity/U2fTokenProvider.cs
+++ b/src/Core/Identity/U2fTokenProvider.cs
@@ -3,7 +3,6 @@ using Microsoft.AspNetCore.Identity;
 using Bit.Core.Models.Table;
 using Bit.Core.Enums;
 using Bit.Core.Models;
-using Bit.Core.Services;
 using Bit.Core.Repositories;
 using Newtonsoft.Json;
 using System.Collections.Generic;
@@ -18,16 +17,13 @@ namespace Bit.Core.Identity
     public class U2fTokenProvider : IUserTwoFactorTokenProvider<User>
     {
         private readonly IU2fRepository _u2fRepository;
-        private readonly IUserService _userService;
         private readonly GlobalSettings _globalSettings;
 
         public U2fTokenProvider(
             IU2fRepository u2fRepository,
-            IUserService userService,
             GlobalSettings globalSettings)
         {
             _u2fRepository = u2fRepository;
-            _userService = userService;
             _globalSettings = globalSettings;
         }
 
@@ -48,7 +44,7 @@ namespace Bit.Core.Identity
 
             var keys = new List<TwoFactorProvider.U2fMetaData>();
 
-            var key1 = provider.MetaData["Key1"] as TwoFactorProvider.U2fMetaData;
+            var key1 = new TwoFactorProvider.U2fMetaData((dynamic)provider.MetaData["Key1"]);
             if(!key1?.Compromised ?? false)
             {
                 keys.Add(key1);
@@ -98,7 +94,7 @@ namespace Bit.Core.Identity
                 return false;
             }
 
-            var provider = user.GetTwoFactorProvider(TwoFactorProviderType.Duo);
+            var provider = user.GetTwoFactorProvider(TwoFactorProviderType.U2f);
             if(!HasProperMetaData(provider))
             {
                 return false;
@@ -106,7 +102,7 @@ namespace Bit.Core.Identity
 
             var keys = new List<TwoFactorProvider.U2fMetaData>();
 
-            var key1 = provider.MetaData["Key1"] as TwoFactorProvider.U2fMetaData;
+            var key1 = new TwoFactorProvider.U2fMetaData((dynamic)provider.MetaData["Key1"]);
             if(!key1?.Compromised ?? false)
             {
                 keys.Add(key1);
@@ -131,10 +127,15 @@ namespace Bit.Core.Identity
                 return false;
             }
 
-            var success = true;
             // User will have a authentication request for each device they have registered so get the one that matches
             // the device key handle
-            var challenge = challenges.First(c => c.KeyHandle == authenticateResponse.KeyHandle);
+            var challenge = challenges.FirstOrDefault(c => c.KeyHandle == authenticateResponse.KeyHandle);
+            if(challenge == null)
+            {
+                return false;
+            }
+
+            var success = true;
             var registration = new DeviceRegistration(key.KeyHandleBytes, key.PublicKeyBytes, key.CertificateBytes,
                 key.Counter);
             try
@@ -155,7 +156,7 @@ namespace Bit.Core.Identity
             var providers = user.GetTwoFactorProviders();
             providers[TwoFactorProviderType.U2f].MetaData["Key1"] = key;
             user.SetTwoFactorProviders(providers);
-            await _userService.SaveUserAsync(user);
+            await manager.UpdateAsync(user);
 
             return success;
         }
diff --git a/src/Core/Models/TwoFactorProvider.cs b/src/Core/Models/TwoFactorProvider.cs
index 81e5820508..1f8e809674 100644
--- a/src/Core/Models/TwoFactorProvider.cs
+++ b/src/Core/Models/TwoFactorProvider.cs
@@ -1,4 +1,5 @@
-using System;
+using Newtonsoft.Json;
+using System;
 using System.Collections.Generic;
 using u2flib.Util;
 
@@ -11,13 +12,27 @@ namespace Bit.Core.Models
 
         public class U2fMetaData
         {
+            public U2fMetaData() { }
+
+            public U2fMetaData(dynamic o)
+            {
+                KeyHandle = o.KeyHandle;
+                PublicKey = o.PublicKey;
+                Certificate = o.Certificate;
+                Counter = o.Counter;
+                Compromised = o.Compromised;
+            }
+
             public string KeyHandle { get; set; }
+            [JsonIgnore]
             public byte[] KeyHandleBytes =>
                 string.IsNullOrWhiteSpace(KeyHandle) ? null : Utils.Base64StringToByteArray(KeyHandle);
             public string PublicKey { get; set; }
+            [JsonIgnore]
             public byte[] PublicKeyBytes =>
                 string.IsNullOrWhiteSpace(PublicKey) ? null : Utils.Base64StringToByteArray(PublicKey);
             public string Certificate { get; set; }
+            [JsonIgnore]
             public byte[] CertificateBytes =>
                 string.IsNullOrWhiteSpace(Certificate) ? null : Utils.Base64StringToByteArray(Certificate);
             public uint Counter { get; set; }
diff --git a/src/Core/Utilities/ServiceCollectionExtensions.cs b/src/Core/Utilities/ServiceCollectionExtensions.cs
index 712cbe364f..b5a749d0e2 100644
--- a/src/Core/Utilities/ServiceCollectionExtensions.cs
+++ b/src/Core/Utilities/ServiceCollectionExtensions.cs
@@ -101,6 +101,7 @@ namespace Bit.Core.Utilities
                 .AddTokenProvider<AuthenticatorTokenProvider>(TwoFactorProviderType.Authenticator.ToString())
                 .AddTokenProvider<YubicoOtpTokenProvider>(TwoFactorProviderType.YubiKey.ToString())
                 .AddTokenProvider<DuoWebTokenProvider>(TwoFactorProviderType.Duo.ToString())
+                .AddTokenProvider<U2fTokenProvider>(TwoFactorProviderType.U2f.ToString())
                 .AddTokenProvider<EmailTokenProvider<User>>(TokenOptions.DefaultEmailProvider);
 
             return identityBuilder;
diff --git a/src/Identity/settings.json b/src/Identity/settings.json
index e052969322..467b1611eb 100644
--- a/src/Identity/settings.json
+++ b/src/Identity/settings.json
@@ -44,7 +44,7 @@
       "aKey": "SECRET"
     },
     "u2f": {
-      "appId": "https://bitwarden.com"
+      "appId": "https://localhost:4001"
     }
   }
 }
diff --git a/src/Sql/dbo/Stored Procedures/U2f_Create.sql b/src/Sql/dbo/Stored Procedures/U2f_Create.sql
index 8cd95cd5a0..c7b85b3569 100644
--- a/src/Sql/dbo/Stored Procedures/U2f_Create.sql	
+++ b/src/Sql/dbo/Stored Procedures/U2f_Create.sql	
@@ -1,10 +1,10 @@
 CREATE PROCEDURE [dbo].[U2f_Create]
     @Id INT,
     @UserId UNIQUEIDENTIFIER,
-    @KeyHandle VARCHAR(50),
-    @Challenge VARCHAR(50),
+    @KeyHandle VARCHAR(200),
+    @Challenge VARCHAR(200),
     @AppId VARCHAR(50),
-    @Version VARCHAR(50),
+    @Version VARCHAR(20),
     @CreationDate DATETIME2(7)
 AS
 BEGIN
diff --git a/src/Sql/dbo/Tables/U2f.sql b/src/Sql/dbo/Tables/U2f.sql
index 1d513c9f9c..6abdf1f3cd 100644
--- a/src/Sql/dbo/Tables/U2f.sql
+++ b/src/Sql/dbo/Tables/U2f.sql
@@ -1,8 +1,8 @@
 CREATE TABLE [dbo].[U2f] (
     [Id]           INT              IDENTITY (1, 1) NOT NULL,
     [UserId]       UNIQUEIDENTIFIER NOT NULL,
-    [KeyHandle]    VARCHAR (MAX)    NULL,
-    [Challenge]    VARCHAR (MAX)    NOT NULL,
+    [KeyHandle]    VARCHAR (200)    NULL,
+    [Challenge]    VARCHAR (200)    NOT NULL,
     [AppId]        VARCHAR (50)     NOT NULL,
     [Version]      VARCHAR (20)     NOT NULL,
     [CreationDate] DATETIME2 (7)    NOT NULL,