diff --git a/LWCredentialProvider/UsbManager.cs b/LWCredentialProvider/UsbManager.cs
index 09b9af8..4144327 100644
--- a/LWCredentialProvider/UsbManager.cs
+++ b/LWCredentialProvider/UsbManager.cs
@@ -4,12 +4,17 @@
 using System.Linq;
 using System.Security.Cryptography;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.Runtime.InteropServices;
 using Microsoft.Win32.SafeHandles;
 // namespace LWCredentialProvider
 // {
     public class USBManager
     {
+        private static readonly Regex DateRegex = new Regex(@"^\d{8}-\d{6}$", RegexOptions.Compiled);
+        private static readonly Regex HashRegex = new Regex(@"^[0-9A-F]{10}$", RegexOptions.Compiled);
+        private static readonly Regex GuidRegex = new Regex(@"^[0-9A-F]{1,32}$", RegexOptions.Compiled);
+
         [DllImport("kernel32.dll", SetLastError = true)]
         private static extern bool DeviceIoControl(
             SafeFileHandle hDevice,
@@ -138,20 +143,20 @@ public static bool CheckUSBKey(string usbKey)
 
 
             // Validate date format
-            if (!System.Text.RegularExpressions.Regex.IsMatch(date, @"^\d{8}-\d{6}$"))
+            if (!DateRegex.IsMatch(date))
                 return false;
 
             Console.WriteLine($"hash: {hash}");
 
 
             // Validate hash format
-            if (!System.Text.RegularExpressions.Regex.IsMatch(hash, @"^[0-9A-F]{10}$"))
+            if (!HashRegex.IsMatch(hash))
                 return false;
 
             Console.WriteLine($"guid: {guid}");
 
             // Validate GUID format
-            if (!System.Text.RegularExpressions.Regex.IsMatch(guid, @"^[0-9A-F]{1,32}$"))
+            if (!GuidRegex.IsMatch(guid))
                 return false;