The Filter-Crypto distribution provides the means to convert your Perl
files into an encrypted, yet still runnable, format to hide the source
code from casual prying eyes.

This is achieved using a Perl source code filter.  The encrypted files,
produced using the Filter::Crypto::CryptFile module automatically have
one (unencrypted) line added to the start of them which loads the
Filter::Crypto::Decrypt module.  The latter is a Perl source code filter
which decrypts the remaining (encrypted) part of the Perl file
on-the-fly when it is run.  See perlfilter if you want to know more
about how Perl source code filters work.

Encrypted files can also be produced more conveniently using the
crypt_file script, or (if you also have the PAR module available) using
the PAR::Filter::Crypto module.  The latter can be utilised by the
standard PAR tools to produce PAR archives in which your Perl files are
encrypted.