Shell Programming and Scripting

Folks,
Is there anyone to help on GPG file encryptions here.
I got a public key from third party. I imported the key in server.
I want to encrypt the public key. But without being signed , the key cannot be encrypted.
When I try to sign the key using lsign command,
I am getting the below message

Code:

Are you really sure that you want to sign this key
with your key: "some name < some_email@url.com>"

By default it is showing a key as my key to sign. The issue is I don't know the passphrase for that key. Because of which I am unable to sign using this key.

Please help me, how can I set someother key as my key by default. or
How can I sign the key using a specific key?
Is there any commands for this?

I am not sure that you are trying to achieve by encrypting their public key.

All you would normally do is add their public key to your keyring using:

Code:

gpg --import <file-containing-their-public-key>