sha512sum

to generate recursively:
find . -type f -exec sha512sum {} \; > sha512sum-${PWD##*/}

to check:
sha512sum -c sha512sum-${PWD##*/} | grep -i fail

ps.: "${PWD##*/}" is only the directory name, like: "pwd | rev | cut -d / -f1 | rev"

from:
http://www.shell-fu.org/lister.php?id=850