Encrypt and Decrypt a File Using GPG Command on Linux

There are many choices on hand to secure your data. However, GPG provides the additional benefit to encrypting your data on a priority basis and transfers them securely over the internet. This article explains about – How to Encrypt and Decrypt a file using GPG command on Linux.

To get more information about GPG, use the following command –

$ gpg -h

The sample output should be like this –

gpg (GnuPG) 1.4.20
Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: ~/.gnupg
Supported algorithms:
Pubkey: RSA, RSA-E, RSA-S, ELG-E, DSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
   CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: MD5, SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2

Syntax: gpg [options] [files]
Sign, check, encrypt or decrypt
Default operation depends on the input data

Commands:

-s,       --sign [file]        make a signature
          --clearsign [file]   make a clear text signature
-b,       --detach-sign        make a detached signature
-e,       --encrypt            encrypt data
-c,       --symmetric          encryption only with symmetric cipher
-d,       --decrypt            decrypt data (default)
          --verify             verify a signature
          --list-keys          list keys
          --list-sigs          list keys and signatures
          --check-sigs         list and check key signatures
          --fingerprint        list keys and fingerprints
-K,       --list-secret-keys   list secret keys
          --gen-key            generate a new key pair
          --delete-keys        remove keys from the public keyring
          --delete-secret-keys remove keys from the secret keyring
          --sign-key          sign a key
          --lsign-key         sign a key locally
          --edit-key          sign or edit a key
          --gen-revoke       generate a revocation certificate
          --export           export keys
          --send-keys        export keys to a key server
          --recv-keys        import keys from a key server
          --search-keys      search for keys on a key server
          --refresh-keys     update all keys from a keyserver
        --import import/merge keys
--card-status print the card status
--card-edit change data on a card
--change-pin change a card's PIN
--update-trustdb update the trust database
--print-md algo [files] print message digests
...............................................................................

While encrypting and decrypting a file, it will ask to Enter passphrase(password) and Repeat passphrase to secure a file

Encrypt a File using GPG

To encrypt a file using GPG, please use the command as shown below –

$ gpg -c abc.txt

In the above command, it is encrypting abc.txt file. To verify it, use the following command –

$ ls

The sample output should be like this –

abc.txt               Final_Url_Weight.csv           site_health_depth5.txt
abc.txt.gpg           FINAL_URL_WEIGHT.db            tp_Crawled_few.txt
check_ageof_site.py   final_url_weight.py
extracting_keywors.py final_url_weight_sqlite.py

Decrypt a File using GPG

To decrypt the above file, use the following command –

$ gpg -o abc.txt -d abc.txt.gpg
gpg: AES encrypted data
Enter passphrase:

Above the command de-crypts the file and stores in same directory.

In the above article, we have learnt – Learn how to Encrypt and Decrypt a file using GPG command on Linux. In our next articles, we will come up with more Linux based tricks and tips. Keep reading!