diff --git a/DepotDownloader/AccountSettingsStore.cs b/DepotDownloader/AccountSettingsStore.cs
index 8bed9622..64078867 100644
--- a/DepotDownloader/AccountSettingsStore.cs
+++ b/DepotDownloader/AccountSettingsStore.cs
@@ -11,8 +11,7 @@ namespace DepotDownloader
     [ProtoContract]
     class AccountSettingsStore
     {
-        [ProtoMember(1, IsRequired = false)]
-        public Dictionary<string, byte[]> SentryData { get; private set; }
+        // Member 1 was a Dictionary<string, byte[]> for SentryData.
 
         [ProtoMember(2, IsRequired = false)]
         public ConcurrentDictionary<string, int> ContentServerPenalty { get; private set; }
@@ -26,7 +25,6 @@ namespace DepotDownloader
 
         AccountSettingsStore()
         {
-            SentryData = new Dictionary<string, byte[]>();
             ContentServerPenalty = new ConcurrentDictionary<string, int>();
             LoginTokens = new Dictionary<string, string>();
         }
diff --git a/DepotDownloader/Steam3Session.cs b/DepotDownloader/Steam3Session.cs
index 206b3b56..09ed25ac 100644
--- a/DepotDownloader/Steam3Session.cs
+++ b/DepotDownloader/Steam3Session.cs
@@ -2,7 +2,6 @@ using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -112,26 +111,8 @@ namespace DepotDownloader
             this.callbacks.Subscribe<SteamUser.LoggedOnCallback>(LogOnCallback);
             this.callbacks.Subscribe<SteamUser.SessionTokenCallback>(SessionTokenCallback);
             this.callbacks.Subscribe<SteamApps.LicenseListCallback>(LicenseListCallback);
-            this.callbacks.Subscribe<SteamUser.UpdateMachineAuthCallback>(UpdateMachineAuthCallback);
 
             Console.Write("Connecting to Steam3...");
-
-            if (details.Username != null)
-            {
-                var fi = new FileInfo(String.Format("{0}.sentryFile", logonDetails.Username));
-                if (AccountSettingsStore.Instance.SentryData != null && AccountSettingsStore.Instance.SentryData.ContainsKey(logonDetails.Username))
-                {
-                    logonDetails.SentryFileHash = Util.SHAHash(AccountSettingsStore.Instance.SentryData[logonDetails.Username]);
-                }
-                else if (fi.Exists && fi.Length > 0)
-                {
-                    var sentryData = File.ReadAllBytes(fi.FullName);
-                    logonDetails.SentryFileHash = Util.SHAHash(sentryData);
-                    AccountSettingsStore.Instance.SentryData[logonDetails.Username] = sentryData;
-                    AccountSettingsStore.Save();
-                }
-            }
-
             Connect();
         }
 
@@ -749,35 +730,6 @@ namespace DepotDownloader
             }
         }
 
-        private void UpdateMachineAuthCallback(SteamUser.UpdateMachineAuthCallback machineAuth)
-        {
-            var hash = Util.SHAHash(machineAuth.Data);
-            Console.WriteLine("Got Machine Auth: {0} {1} {2} {3}", machineAuth.FileName, machineAuth.Offset, machineAuth.BytesToWrite, machineAuth.Data.Length);
-
-            AccountSettingsStore.Instance.SentryData[logonDetails.Username] = machineAuth.Data;
-            AccountSettingsStore.Save();
-
-            var authResponse = new SteamUser.MachineAuthDetails
-            {
-                BytesWritten = machineAuth.BytesToWrite,
-                FileName = machineAuth.FileName,
-                FileSize = machineAuth.BytesToWrite,
-                Offset = machineAuth.Offset,
-
-                SentryFileHash = hash, // should be the sha1 hash of the sentry file we just wrote
-
-                OneTimePassword = machineAuth.OneTimePassword, // not sure on this one yet, since we've had no examples of steam using OTPs
-
-                LastError = 0, // result from win32 GetLastError
-                Result = EResult.OK, // if everything went okay, otherwise ~who knows~
-
-                JobID = machineAuth.JobID, // so we respond to the correct server job
-            };
-
-            // send off our response
-            steamUser.SendMachineAuthResponse(authResponse);
-        }
-
         private static void DisplayQrCode(string challengeUrl)
         {
             // Encode the link as a QR code