Basic File Encryption

These days, when users think of encryption, they usually turn to PGP, OpenSSL, or LUKS. Sometimes, though, you may not want encrypted transmissions or filesystems. When all you want is to encrypt a file or two, all you need is one of the crypt commands – bcrypt [1], ccrypt [2], or mcrypt [3]. All three are specialized for encrypting files and can even have a feature or two that are missing from the better known encryption applications.

All three take their name from crypt [4], an obsolete Unix command. crypt was broken long ago, but bcrypt, ccrypt, and mcrypt are all up-to-date encryption tools. In some distributions, mcrypt may use crypt as an alias.

All three, however, are simple tools that are easy to learn. With each, you enter the command to encrypt or decrypt with the desired options and then enter a passphrase to complete the operation.

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