Before someone points it out,

my $remote_compare="rexec $host -l $user \"/usr/bin/chksum $file\"";

Should actually be:

my $remote_compare="rexec $host \"/usr/bin/chksum $file\"";

In testing, I was prompted for a password whenever I used '-l $user' even if I was running as the same user. Luckily, I am running the script as the same user as $user.