This is Crypt::CBC version 1.0, a Perl-only implementation of the cryptographic cipher block chaining mode (CBC). In combination with a block cipher such as Crypt::DES or Crypt::IDEA, you can encrypt and decrypt messages of arbitrarily long length. The encrypted messages are compatible with the encryption format used by B<SSLeay>. In addition to this module you will need the following: 1. MD5 Required for key and iteration vector generation. 2. Crypt::DES Required for the DES encryption algorithm. 3. Crypt::IEA Required for the IDEA encryption algorithm. You can find each of these modules on a CPAN near you. In order to get the DES and IDEA modules to compile on my system (Linux), I found I had to change a few of the #include directives. For Crypt::DES, I had to change "#include <machine/types.h>" to "#include <sys/types.h>" in the "des.h" file. For Crypt::IDEA, I had to make the same change in the file "idea.h". In addition, I had to change "#include <machine/endian.h>" to "#include <endian.h>" in the file "idea.c". Your mileage may vary. To Install Crypt::CBC: 1. perl Makefile.PL 2. make 3. make test 4. make install Lincoln D. Stein lstein@cshl.org