GNU Privacy Guard (GPG Key)

A GPG key is a cryptographic key pair used for secure communication, data integrity, and digital signatures. It consists of a public key for encryption and a private key for decryption.

In the context of Ubuntu Package Management, the GPG key to verify the integrity of the package files after they have been downloaded. This ensures that the packages haven’t been tampered with and are coming from a trusted source.

Difference with SSH key?

GPG Key: Used primarily for secure email communication, file encryption, and digital signatures. Consists of a public key for encryption and a private key for decryption.

SSH Key: Used for secure shell (SSH) login to remote servers. Comprises a public key that is placed on the server and a private key that remains on your local machine.