Encrypt/Decrypt Files in Linux using Ccrypt

Last Updated : 14 Oct, 2024

Ccrypt is a command line tool for encryption and decryption of data. Ccrypt is based on the Rijndael cipher, the same cipher used in the AES standard. On the other hand, in the AES standard, a 128-bit block size is used, whereas ccrypt uses a 256-bit block size. Ccrypt commonly uses the .cpt file extension for encrypted files.

It is a lightweight tool, and the installation and use of this tool are pretty easy.
It is designed to overcome the shortcomings of standard unix crypt utility.

Installation

sudo apt-get install ccrypt // in ubuntu

Syntax

ccrypt [options] [file]

Basic Ccrypt Command Example

If you just want to encrypt the file use the following command

ccrypt filename.txt

This command prompts to enter the password for encryption which is going to be used in further by creating a file as 'filename.txt.cpt'.

Key Options used with the Ccrypt Command

Option	Description
-e	Encrypt the file you entrered
-d	Decrypt the file
-k	Used to specify the key directly but use with caution
-V	Shows the version information
-h	This displays the help informations
-o FILE	This command specifies an output file for encrypted/decrypted data
-r	Uses recursion technique to encrypt data files in directory

This are the additional options in Ccrypt

-h: This displays the help option for the following command we can also use man ccrpyt to get the help.
-v: Enables the verbose mode for detailed output.
-V: Displays the version information for Ccrpyt

-e, --encrypt :Encrypt. This is the default mode. If filename arguments are given, encrypt the files and append the suffix .cpt which is shown further to their names. Otherwise, run as a filter. This will encrypt the file and rename it to .cpt extension

-d, --decrypt: Decrypt. If filename arguments are given, decrypt the files and strip the suffix .cpt from the filenames, if present. Otherwise, run as a filter. This will asks for the dencryption which used to encrypt the file.

Keyfile usage to encrypt the file : This commands let you read a keyfile environment variable to encrypt a file.

keyfile — Using a Key File for Encryption

Conclusion

Ccrypt is a highly useful and lightweight tools in linux environment used to encypt and decrypt files, providing a secure yet acesssible way to protcet the sensitive data and infromations from intruders. Its ease of use, combined with powerful encryption based on the Rijndael cipher(AES), makes it an excellent choice of more advancecd tools aamong the users.

With options we can encrypt/decrypt the files and directories for our own means, and features such as automatic deletion, of unencrypted originals, Ccrypt is versatile enough for various usage environments.