The crypt(C) command encodes and decodes files for security. When using crypt, you have to assign a password (key) to encode the file. The same password is used to decode the file.
If you do not give a password with the crypt command, the system prompts you for one. For security, the screen does not display the password as you type it in.
Password security is the most vulnerable part of the crypt command. The best way to ensure your security is to select an uncommon group of characters. The password should be no more than eight letters or numbers long.
A file can be encrypted in the shell mode using crypt,
or in the edit mode using the -x or X option.
When you are ready to decrypt the file, you can use the
crypt command in the shell mode.
The following is the command format to encrypt a file:
crypt < oldfile > newfile
The system prompts you for a password.
Before removing the unencrypted oldfile, make sure the encrypted newfile can be decrypted using the appropriate password.
To decrypt a file, redirect the encrypted file to a new file you
can read. The command to decrypt a file is as follows:
crypt < encrypted_file > new_filename