My copy of "The Perl 5 Programmer's Reference"

Has a review here: The Perl 5 Programmer's Reference. I think I saw it in a store or some illegal copy somewhere on the net, and it is barely more than the perldoc that came with perl.

says it uses DES. It's from 1997. Next time I'll double check with perldoc.

Just ran a search for "DES" on my local POD for perl 5.18.1 (from 2013), and got only one match: perlcygwin allows to compile perl with -lcrypt, explicitly mentioning DES: "The crypt package distributed with Cygwin is a Linux compatible 56-bit DES crypt port by Corinna Vinschen."

Since the book is from 1997, and is essentially a printed perldoc, a Perl version from that time should mention DES.

perl 5.004, dated 15 May 1997 (first from 1997 on CPAN)

perlfunc says: "Encrypts a string exactly like the crypt(3) function in the C library", no trace of DES. Not even a brute force search is successful, only tons of false positives (DESTROY, DESCRIPTION).

perl 5.003_07, dated 10 Oct 1996 (the oldest one on CPAN)

perlfunc has the same text, and the search has again only false positives.

So, where does the DES information come from?

A really brute force search across all perl versions on perl5.git.perl.org has quite a few matches with many false positives and many test scripts, but none before 1997-12-24. Perl 5.003_07 has only false positives, i.e. no trace of DES in Perl 5.003_07. Older versions have been excluded by the git brute force search.

The Win32/cygwin ports had DES for ages, using a third party DES crypt() implementation. But for other systems, DES is not mentioned (or at least I did not find any hints.)

So the book must be either wrong (assuming crypt implements DES for all operating systems) or badly worded (making you think Win32 DES crypt or DES crypt in some libc apply to all operating systems).

Alexander