# $self is a CGI::Application object
my $encrypted = encrypt_address(
    address => $address,
    key     => $self -> param('encryption_key'),
    cipher  => $self -> param('encryption_cipher') );

....

sub encrypt_address {
    my %arg = @_;

    require Crypt::CBC;
    Crypt::CBC -> new(
        { key    => $arg{key},
          cipher => $arg{cipher} } )

        -> encrypt_hex( $arg{address} );
}