diff --git a/src/Orchard.Tests/Utility/Extensions/StringExtensionsTests.cs b/src/Orchard.Tests/Utility/Extensions/StringExtensionsTests.cs
index 66848124a..d266d85f8 100644
--- a/src/Orchard.Tests/Utility/Extensions/StringExtensionsTests.cs
+++ b/src/Orchard.Tests/Utility/Extensions/StringExtensionsTests.cs
@@ -282,5 +282,21 @@ namespace Orchard.Tests.Utility.Extensions {
             Assert.That("abc".Translate("d".ToCharArray(), "d".ToCharArray()), Is.StringMatching("abc"));
             Assert.That("abc".Translate("abc".ToCharArray(), "def".ToCharArray()), Is.StringMatching("def"));
         }
+
+        [Test]
+        public void ShouldEncodeToBase64() {
+            Assert.That("abc".ToBase64(), Is.EqualTo("YWJj"));
+        }
+
+        [Test]
+        public void ShouldDecodeFromBase64() {
+            Assert.That("YWJj".FromBase64(), Is.EqualTo("abc"));
+        }
+
+        [Test]
+        public void ShouldRoundtripBase64() {
+            Assert.That("abc".ToBase64().FromBase64(), Is.EqualTo("abc"));
+            Assert.That("YWJj".FromBase64().ToBase64(), Is.EqualTo("YWJj"));
+        }
     }
 }
diff --git a/src/Orchard.Web/Modules/Orchard.SecureSocketsLayer/Orchard.SecureSocketsLayer.csproj b/src/Orchard.Web/Modules/Orchard.SecureSocketsLayer/Orchard.SecureSocketsLayer.csproj
index ce79a3d37..779e40f5a 100644
--- a/src/Orchard.Web/Modules/Orchard.SecureSocketsLayer/Orchard.SecureSocketsLayer.csproj
+++ b/src/Orchard.Web/Modules/Orchard.SecureSocketsLayer/Orchard.SecureSocketsLayer.csproj
@@ -90,6 +90,7 @@
     <Compile Include="Filters\SecureSocketsLayersFilter.cs" />
     <Compile Include="Handlers\SslSettingsPartHandler.cs" />
     <Compile Include="Models\SslSettingsPart.cs" />
+    <Compile Include="Services\SecureSocketsLayerSettingsProvider.cs" />
     <Compile Include="Services\ISecureSocketsLayerService.cs" />
     <Compile Include="Services\SecureSocketsLayerService.cs" />
   </ItemGroup>
diff --git a/src/Orchard.Web/Modules/Orchard.SecureSocketsLayer/Services/SecureSocketsLayerSettingsProvider.cs b/src/Orchard.Web/Modules/Orchard.SecureSocketsLayer/Services/SecureSocketsLayerSettingsProvider.cs
new file mode 100644
index 000000000..d99890e67
--- /dev/null
+++ b/src/Orchard.Web/Modules/Orchard.SecureSocketsLayer/Services/SecureSocketsLayerSettingsProvider.cs
@@ -0,0 +1,17 @@
+using Orchard.Environment.Extensions;
+using Orchard.Security;
+
+namespace Orchard.SecureSocketsLayer.Services {
+    [OrchardSuppressDependency("Orchard.Security.Providers.DefaultSslSettingsProvider")]
+    public class SecureSocketsLayerSettingsProvider : ISslSettingsProvider {
+        private readonly ISecureSocketsLayerService _secureSocketsLayerService;
+
+        public SecureSocketsLayerSettingsProvider(ISecureSocketsLayerService secureSocketsLayerService) {
+            _secureSocketsLayerService = secureSocketsLayerService;
+        }
+
+        public bool GetRequiresSSL() {
+            return _secureSocketsLayerService.GetSettings().Enabled;
+        }
+    }
+}
diff --git a/src/Orchard/Orchard.Framework.csproj b/src/Orchard/Orchard.Framework.csproj
index 02519fce4..9a7a87cda 100644
--- a/src/Orchard/Orchard.Framework.csproj
+++ b/src/Orchard/Orchard.Framework.csproj
@@ -148,6 +148,8 @@
     <Reference Include="System.Xml.Linq" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Security\ISslSettingsProvider.cs" />
+    <Compile Include="Security\Providers\DefaultSslSettingsProvider.cs" />
     <Compile Include="StaticHttpContextScope.cs" />
     <Compile Include="StaticHttpContextScopeFactory.cs" />
     <Compile Include="Caching\DefaultCacheContextAccessor.cs" />
diff --git a/src/Orchard/Security/ISslSettingsProvider.cs b/src/Orchard/Security/ISslSettingsProvider.cs
new file mode 100644
index 000000000..9e411b178
--- /dev/null
+++ b/src/Orchard/Security/ISslSettingsProvider.cs
@@ -0,0 +1,11 @@
+using System;
+
+namespace Orchard.Security {
+    public interface ISslSettingsProvider : IDependency {
+
+        /// <summary>
+        /// Gets whether authentication cookies should only be transmitted over SSL or not.
+        /// </summary>
+        bool GetRequiresSSL();
+    }
+}
diff --git a/src/Orchard/Security/Providers/DefaultSslSettingsProvider.cs b/src/Orchard/Security/Providers/DefaultSslSettingsProvider.cs
new file mode 100644
index 000000000..624ec7b62
--- /dev/null
+++ b/src/Orchard/Security/Providers/DefaultSslSettingsProvider.cs
@@ -0,0 +1,15 @@
+using System.Web.Security;
+
+namespace Orchard.Security.Providers {
+    public class DefaultSslSettingsProvider : ISslSettingsProvider {
+        public bool RequireSSL { get; set; }
+
+        public DefaultSslSettingsProvider() {
+            RequireSSL = FormsAuthentication.RequireSSL;
+        }
+
+        public bool GetRequiresSSL() {
+            return RequireSSL;
+        }
+    }
+}
diff --git a/src/Orchard/Security/Providers/FormsAuthenticationService.cs b/src/Orchard/Security/Providers/FormsAuthenticationService.cs
index b31b04b5c..3619c2ed5 100644
--- a/src/Orchard/Security/Providers/FormsAuthenticationService.cs
+++ b/src/Orchard/Security/Providers/FormsAuthenticationService.cs
@@ -3,25 +3,34 @@ using System.Web;
 using System.Web.Security;
 using Orchard.Environment.Configuration;
 using Orchard.Logging;
-using Orchard.ContentManagement;
 using Orchard.Mvc;
 using Orchard.Mvc.Extensions;
 using Orchard.Services;
+using Orchard.Utility.Extensions;
 
 namespace Orchard.Security.Providers {
     public class FormsAuthenticationService : IAuthenticationService {
+        private const int _version = 3;
+
         private readonly ShellSettings _settings;
         private readonly IClock _clock;
-        private readonly IContentManager _contentManager;
+        private readonly IMembershipService _membershipService;
         private readonly IHttpContextAccessor _httpContextAccessor;
+        private readonly ISslSettingsProvider _sslSettingsProvider;
         private IUser _signedInUser;
         private bool _isAuthenticated;
 
-        public FormsAuthenticationService(ShellSettings settings, IClock clock, IContentManager contentManager, IHttpContextAccessor httpContextAccessor) {
+        public FormsAuthenticationService(
+            ShellSettings settings, 
+            IClock clock, 
+            IMembershipService membershipService, 
+            IHttpContextAccessor httpContextAccessor,
+            ISslSettingsProvider sslSettingsProvider) {
             _settings = settings;
             _clock = clock;
-            _contentManager = contentManager;
+            _membershipService = membershipService;
             _httpContextAccessor = httpContextAccessor;
+            _sslSettingsProvider = sslSettingsProvider;
 
             Logger = NullLogger.Instance;
             
@@ -35,11 +44,12 @@ namespace Orchard.Security.Providers {
         public void SignIn(IUser user, bool createPersistentCookie) {
             var now = _clock.UtcNow.ToLocalTime();
             
-            // the cookie user data is {userId};{tenant}
-            var userData = String.Concat(Convert.ToString(user.Id), ";", _settings.Name); 
+            // the cookie user data is {userName.Base64};{tenant}
+            // the username is encoded to base64 to prevent collisions with the ';' seprarator
+            var userData = String.Concat(Convert.ToString(user.UserName).ToBase64(), ";", _settings.Name); 
 
             var ticket = new FormsAuthenticationTicket(
-                1 /*version*/,
+                _version,
                 user.UserName,
                 now,
                 now.Add(ExpirationTimeSpan),
@@ -50,8 +60,8 @@ namespace Orchard.Security.Providers {
             var encryptedTicket = FormsAuthentication.Encrypt(ticket);
 
             var cookie = new HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket) {
-                HttpOnly = true, 
-                Secure = FormsAuthentication.RequireSSL, 
+                HttpOnly = true, // can't retrieve the cookie from JavaScript
+                Secure = _sslSettingsProvider.GetRequiresSSL(), 
                 Path = FormsAuthentication.FormsCookiePath
             };
 
@@ -108,30 +118,37 @@ namespace Orchard.Security.Providers {
             }
 
             var formsIdentity = (FormsIdentity)httpContext.User.Identity;
+
+            // if the cookie is from a previous format, ignore
+            if (formsIdentity.Ticket.Version != _version) {
+                return null;
+            }
+
             var userData = formsIdentity.Ticket.UserData ?? "";
 
-            // the cookie user data is {userId};{tenant}
+            // the cookie user data is {userName};{tenant}
             var userDataSegments = userData.Split(';');
             
             if (userDataSegments.Length < 2) {
                 return null;
             }
 
-            var userDataId = userDataSegments[0];
+            var userDataName = userDataSegments[0];
             var userDataTenant = userDataSegments[1];
 
+            try {
+                userDataName = userDataName.FromBase64();
+            }
+            catch {
+                return null;
+            }
+
             if (!String.Equals(userDataTenant, _settings.Name, StringComparison.Ordinal)) {
                 return null;
             }
 
-            int userId;
-            if (!int.TryParse(userDataId, out userId)) {
-                Logger.Error("User id not a parsable integer");
-                return null;
-            }
-
             _isAuthenticated = true;
-            return _signedInUser = _contentManager.Get(userId).As<IUser>();
+            return _signedInUser = _membershipService.GetUser(userDataName);
         }
 
         private string GetCookiePath(HttpContextBase httpContext) {
diff --git a/src/Orchard/Utility/Extensions/StringExtensions.cs b/src/Orchard/Utility/Extensions/StringExtensions.cs
index d1290b794..1e66a8248 100644
--- a/src/Orchard/Utility/Extensions/StringExtensions.cs
+++ b/src/Orchard/Utility/Extensions/StringExtensions.cs
@@ -348,5 +348,13 @@ namespace Orchard.Utility.Extensions {
             var pattern = String.Format("{0}", String.Join("|", replacements.Keys));
             return Regex.Replace(original, pattern, match => replacements[match.Value]);
         }
+
+        public static string ToBase64(this string value) {
+            return Convert.ToBase64String(Encoding.UTF8.GetBytes(value));
+        }
+
+        public static string FromBase64(this string value) {
+            return Encoding.UTF8.GetString(Convert.FromBase64String(value));
+        }
     }
 }
\ No newline at end of file