Sharing an encrypted file between a group of people Is there any way to share an encrypted file with a group?
In the other words, can I encrypt a file with a public key so that each person in a group decrypt it with his/her private key?

Is there any way that I have a public key and some different private key for it?

I want to find a way to encrypt a file with a public key, and then produce some private keys from this public key, so that whenever I wanted to share that file with some person, I gave him/her a private key from this set to decrypt my file.
Yes, you encrypt the file with a symmetric key, then encrypt that symmetric key with each of the recipients public keys. gpg can do this by adding multiple --recipient options.