From: allen::rebolforces::com at: 30-Aug-2000 10:44
checksum/secure was added in core v2.3, but wasn't documented in the release
notes. So for all those curious about it, here are some notes from Bo.
CHECKSUM/SECURE is based on SHA1. MD5 is no longer considered to be
completely secure and SHA1 is the successor. Here is the REBOL-
computed probability of two documents getting the same checksum:
>> 1 / (2 ** 160)
In other words, it's much more likely that you would win the US lottery
jackpot numerous times.