The only way to decrypt it is with the private key that corresponds to the public key used to encrypt it. If you don't have a PGP key already, there's no way for you to decrypt it. Read about how PGP works. There's a really simple, one-paragraph explanation in the link I posted above: You create a pair of keys that are mathematically related to each other, one is public and the other is private. Never share your private key with anyone. Give your public key to your friends. Collect public keys from your friends. Use their public keys to encrypt messages to them. They use your public key to encrypt messages to you. You use your private key to decrypt messages.