The scrypt key derivation function was originally developed for use in
the Tarsnap online backup system and is designed to be far more secure
against hardware brute-force attacks than alternative functions such as
PBKDF2 or bcrypt.

A simple password-based encryption utility is available as a
demonstration of the scrypt key derivation function. On modern hardware
and with default parameters, the cost of cracking the password on a file
encrypted by scrypt enc is approximately 100 billion times more than the
cost of cracking the same password on a file encrypted by openssl enc;
this means that a five-character password using scrypt is stronger than
a ten-character password using openssl.

In addition to the scrypt command-line utility, a development library
libscrypt-kdf can be built and installed by setting the LIB environment
variable: LIB=yes ./scrypt.SlackBuild