🔒GPG

Theory

gpg is the OpenPGP (Pretty Good Privacy) part of the GNU Privacy Guard (GnuPG). It is a tool to provide digital encryption and signing services using the OpenPGP standard. gpg features complete key management and all the bells and whistles you would expect from a full OpenPGP implementation.

The gpg utility has a lot of options, but fortunately for us, encrypting and decrypting are easy to do and only require that you know three options for quick use: Create or encrypt (-c), decrypt (-d), and extract and decrypt (no option).

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Practical

Encrypt a file

The quick method for encrypting a file is to issue the gpg command with the -c (create) option:

echo This is an encryption test > file1.txt

gpg -c file1.txt

file file2.txt.gpg

mv file2.txt.gpg testfile01.doc

file testfile01.doc

Decrypt a file

If you want to extract the original file while decrypting it, strangely enough, you issue the gpg command with no options.

gpg cfile.txt.gpg 

Decrypt using key

gpg --import b_secret.asc

gpg --decrypt b_txt.pgp

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REFERENCES

• https://superuser.com/questions/920793/how-to-specify-private-key-when-decrypting-a-file-using-gnupg

• https://www.redhat.com/sysadmin/encryption-decryption-gpg

• https://www.tecmint.com/gpg-encrypt-decrypt-files/