ACL is a fairly complete programming language, so I'm sure you could
code CRC-32 in it if you wanted to. OTOH, it's probably easier to just
tap into the java.util.zip package and use their implementation. If you
want to write most of your code in ACL and just invoke the java code for
this, you can bridge to java from ACL using the java_constructor(),
java_instance(), etc. functions in ACL.