I'm using SHA-1 to detect duplicates in a program handling files. It is not required to be cryptographic strong and may be reversible. I found this list of fast
copytree
gmail.js
acf-gutenberg
installshield-2012
r-ranger
tightvnc
android-ui
snakeyaml
mysql2
venia
workflow-activity
data-binding
sign-in-with-apple
nested-views
spectra
system-generator
mkdirs
typekit
nvvp
user-defined-fields
android-log
pajek
quartz-graphics
mplab-x
jakarta-ee
google-dataflow
systemd-journald
modern-ui
inotifypropertychanged
jquery-slider