Can the public key be derived from the private key?

Yes, you can derive the public key from the private key. In SSH and other public-key cryptography systems, the private key contains all the information needed to generate the public key.

If your private key is an RSA private key, you can use ssh-keygenthe command to generate the corresponding public key:

ssh-keygen -y -f /path/to/private/key > /path/to/public/key.pub

In this command:

• -yoption tells to ssh-keygenderive the public key from the provided private key.
• -fThe option is followed by the path to the private key file.
• The final >redirects the public key output into a file.

Make sure you replace /path/to/private/keyand /path/to/public/key.pubwith the actual paths to your private and new public key files.

This command will generate a new public key file, which is the public key derived from the private key. The generated public key should be exactly the same as your original public key.