Monday, March 17, 2014

UNIX/LINUX - How to encrypt/decrypt a text file

crypt command can be used to encrypt/decrypt a particular text file in UNIX/LINUX. It is a simple encryption algorithm which works on a secret-key basis. It encrypts or decrypts a stream of data from standard input, and writes the result to standard output. Encryption and decryption is a symmetric process.

This will create an encrypted file enTextFile.txt  from a text file textFile.txt. You can use either of the commands both does one and the same task.

crypt ENCRYPTION_KEY < textFile.txt > enTextFile.txt


cat textFile.txt | crypt > enTextFile.txt

This will decrypt an encrypted file enTextFile.txt and store the output in textFile.txt

crypt ENCRYPTION_KEY < enTextFile.txt (to show data on console)
crypt ENCRYPTION_KEY < enTextFile.txt > textFile.txt


cat enTextFile.txt | crypt > textFile.txt