You can encrypt and decrypt the file using openssl command line. Somehow you will need to encrypt your important file with a secret key.
openssl enc -aes-256-cbc -in [input_file] -out [output_file]
Then Enter 2 times your secret key (this should be hard to guess and don't loose it)
openssl enc -aes-256-cbc -d -in [input_file] > [output_file]
Then enter your secret key to decrypt the content !
Notice : should use a 10-char length secret with alpha nums and special characters