Easy Steps to Clear PuTTY's Cached SSH Host Keys in Windows 11

Table of Contents

1. Introduction
2. Connecting to a Server via SSH
3. Caching Server's Host Key in Putty
4. Clearing or Deleting Putty's Cached SSH Host Keys
5. Using the Registry Editor
   • 5.1 Opening the Registry Editor
   • 5.2 Navigating to the Putty SSH Host Keys
   • 5.3 Deleting the Cached SSH Host Keys
6. Conclusion

Article

1. Introduction

When connecting to a server via SSH using Putty on Windows 11, you may encounter a prompt regarding caching the server's host key in the registry. This prompt is a security measure to ensure the authenticity of the server. In this article, we will discuss how to clear or delete Putty's cached SSH host keys in Windows 11's registry editor.

2. Connecting to a Server via SSH

To begin, copy the IP address of the server you want to connect to. Open Putty, paste the IP address in the hostname section, and click on "Open". If this is your first time connecting to the server, a security alert will appear regarding the server's host key not being cached. You can choose to accept, cancel, or connect without caching the key.

3. Caching Server's Host Key in Putty

If you choose to accept the caching of the server's host key, Putty will cache it in the Windows registry. This ensures that future connections to the server do not prompt for caching the host key again.

4. Clearing or Deleting Putty's Cached SSH Host Keys

If you want to clear or delete Putty's cached SSH host keys for your server and other servers, follow the steps below.

5. Using the Registry Editor

5.1 Opening the Registry Editor

1. Navigate to your taskbar and click on the search bar.
2. Search for "registry editor" and open the best match, which should be the "Registry Editor" app.
3. If prompted by the User Account Control, click "Yes" to open the registry editor.

5.2 Navigating to the Putty SSH Host Keys

1. In the registry editor, look for "HKEY_CURRENT_USER" and click on the arrow next to it.
2. Scroll down and locate "Software" and click on the arrow next to it.
3. Look for "Simon Tatum" and click on the arrow next to it.
4. Click on the arrow next to "Putty".
5. Click on "SSH host Keys".

5.3 Deleting the Cached SSH Host Keys

1. On the right-hand side, you will see all of Putty's cached SSH host keys.
2. To clear all SSH host keys, left-click and drag to highlight them all, then right-click and select "Delete".
3. If you only want to delete specific SSH host keys, right-click on the desired key and select "Delete".
4. Confirm the deletion in the popup window.
5. Close the registry editor.

6. Conclusion

In conclusion, this article provided a guide on how to clear or delete Putty's cached SSH host keys in Windows 11's registry editor. By following these steps, you can manage the cached host keys for your servers and enhance the security of your SSH connections.

Highlights:

• Clearing or deleting Putty's cached SSH host keys in Windows 11's registry editor.
• Ensuring the authenticity of servers when connecting via SSH.
• Using the registry editor to navigate and delete the cached SSH host keys.
• Enhancing the security of SSH connections.

FAQ:

Q: Can clearing or deleting Putty's cached SSH host keys cause system instability? A: Clearing or deleting the cached SSH host keys in Putty should not cause system instability. However, it is recommended to proceed with caution and ensure that you are deleting the correct keys.

Q: Will Putty prompt for caching the server's host key after clearing the cached keys? A: Yes, after clearing the cached SSH host keys, Putty will prompt for caching the server's host key again when connecting to the server for the first time.

Q: Can I selectively delete specific SSH host keys in Putty? A: Yes, you can selectively delete specific SSH host keys in Putty by navigating to the specific key in the registry editor and deleting it.

Q: How can I ensure the security of my SSH connections? A: To ensure the security of your SSH connections, it is recommended to regularly update and delete cached SSH host keys, use strong passwords, and keep your SSH client and server software up to date.

Q: Is it necessary to clear or delete Putty's cached SSH host keys? A: Clearing or deleting Putty's cached SSH host keys is not always necessary. However, it can be beneficial in cases where you want to refresh the cached keys or if you suspect any security vulnerabilities.