I have just learned about using PGP/GPG for email encryption and one thing has always bugged me:
How is it possible that a message encrypted with somebody's public key can be decrypted only with that persons privated key?
This concept of asymetric encryption is not very intuitive for me. Simply said I would except that the process to encrypt with the public key should be unique and therefore be able to be reverted with the same key.
What's the key operation that ensures this is not possible?