coredump and security

[Alain De Vos]

Got rc.conf,

kern.coredump=1                          #enable coredump
kern.sugid_coredump=1                    #changed credential programs dump core
kern.corefile=/var/coredumps/%U/%N.core

Now I want core dumps to be write by everyone but only readable by root.
What chmod
/var/coredumps
/var/coredumps/0
/var/coredumps/1001
do I use ?