Encrypting a file with AES256
$ gpg -c -a --cipher-algo AES256 --no-use-agent -o mydata.gpg mydata.txt
Notes
-c - encrypt with a symmetric cipher using a passphrase
-a (–armor) - the output will be base64 encoded
To see all cipher algorithms, run ‘gpg –version’
Decrypting the file
$ gpg --no-use-agent -o mydata.txt -d mydata.gpg
To create a key
gpg --gen-key
To export a public key into file publickey.asc
gpg --export -a "User Name" > publickey.asc
To export a private key
gpg --export-secret-key -a "User Name" > privatekey.asc
To import a public key
gpg --import publickey.asc
To import a private key
gpg --allow-secret-key-import --import privatekey.asc
To trust the key
gpg --edit-key KEYNAME
trust
quit
Exporting a GPG Key Using the Command Line
gpg --keyserver hkp://subkeys.pgp.net --send-key KEYNAME
For //KEYNAME//, substitute the key ID of your primary keypair.
To list the keys in your public key ring
gpg --list-keys
To list the keys in your secret key ring:
gpg --list-secret-keys
To encrypt data, use:
gpg -e -u "Sender User Name" -r "Receiver User Name" somefile
To decrypt data, use:
gpg -o decryptedfile -d encryptedfile.gpg
Find and import GPG Public Key based on name or email. Useful when you don’t know or forgot ID of the key.
gpg --keyserver hkp://subkeys.pgp.net --search-keys NAMEorEMAILpattern
gpg --keyserver hkp://subkeys.pgp.net --recv-key 0x9F600825
http://blog.tremily.us/posts/GnuPG_maintenance/
I used as a source Charles Lockhart’s GPG Cheat Sheet
See also