Linux : HowTo Encrypt And Decrypt Files With A Password using GPG.
To encrypt and decrypt files with a password, use gpg command. It is an encryption and signing tool for Linux/UNIX like operating systems.
GnuPG stands for GNU Privacy Guard and is GNU’s tool for secure communication and data storage. It can be used to encrypt data and to create digital signatures.
Please note that if you ever forgot your password (passphrase), you cannot recover the data as it use very strong encryption.