Strong but not crypto-strong checksum

I wrote a simple script which acts like tee, but instead of storing
the contents of the stream, it stores checksums of the stream.  Later
one can check the integrity of a copy of the stream.

The intent is to put it between mkisofs and cdrecord, then validate
the CD by checking the output of readcd.  However, the current
implementation (using *::MD5 module) takes too much of the resources
(circa 50% CPU with 4x DVD-R stream on this Athlon 850).

Obviously, md5 is an overkill in this situation, when errors are not
due to a malicious agency.  Is there a lower overhead strong checksum
module for Perl?  (I mean something much stronger than pack '%32',
which would miss many patterns of errors.)

Thanks,
Ilya