How to Force 128-bit Data Encryption for RAS (172215)


The information in this article applies to:

  • Microsoft Windows NT Workstation 4.0
  • Microsoft Windows NT Server 4.0
  • Microsoft Windows 95
This article was previously published under Q172215
IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry

SUMMARY

With the release of the 128-bit Service Pack 3 (SP3) for Windows NT 4.0, RAS clients can now negotiate 128-bit RAS data encryption with a Windows NT 4.0 RAS server. Normal RAS data encryption is 40-bit. RAS clients that can take advantage of 128-bit data encryption are Windows NT Server or Workstation 4.0 with SP3 128-bit and Windows 95 Dial-Up Networking 1.2 128- bit.

MORE INFORMATION

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To enable 128-bit RAS data encryption on an NT 4.0 SP3 128-bit RAS server, use the following steps:
  1. in Control Panel, double-click Network , and then click Services.
  2. Click Remote Access Service, and tjem click Properties.
  3. Click Network, and then click Require Microsoft encrypted authentication.
  4. Click Require data encryption, and then click OK.
  5. Click Continue, and then click Close.
  6. Click No when you receive a prompt to restart the computer.
  7. Start Registry Editor (Regedit.exe or Regedt32.exe).
  8. Navigate to the following registry subtree:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\PPP\COMPCP

  9. Click Edit, click Add Value, and then enter the following information:

    Value Name: ForceStrongEncryption
    Value Type: DWORD
    Value Data: 1

  10. Exit Registry Editor, and then restart the computer.
With 128-bit RAS encryption enabled, you will see one or more event log messages in Event Viewer when RAS users connect using RAS or PPTP. If the RAS client supports 128-bit RAS data encryption, the computer may log the following event:
Event ID: 20107
Source: RemoteAccess
Description: The user RAS connected to port COM1 using strong encryption.
If the RAS client does not support 128-bit RAS data encryption, the computer may log the following event:
Event ID: 20077
Source: RemoteAccess
Description: An error occurred in the Point to Point Protocol module on port COM1. The remote computer does not support the required encryption type.
A Windows 95 client that fails with the above event log may receive the following error message:
Dial-Up Networking
Error 629: You have been disconnected from the computer you dialed.
Double-click the connection to try again.
A Windows NT client that fails with the above event log may receive the following error message:
Error Connecting to RAS server
Disconnected.
Error 629: The port was disconnected by the remote machine.
For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

169895 Enabling 128-bit Encryption for Routing and Remote Access

Modification Type:MajorLast Reviewed:11/17/2003
Keywords:kbDialUp kbinfo kbnetwork KB172215
©2003 Microsoft Corporation. All rights reserved.