If HTTP authentication is forced, cron jobs will need to authenticate themselves. See Configuring cron jobs for more details on configuring cron jobs. These examples show how to add a user name and password (note: Lynx does not support digest authentication):

45 * * * * /usr/bin/lynx -auth=username:password -source http://example.com/cron.php

45 * * * * /usr/bin/wget --user=username --password=password -O - -q http://example.com/cron.php

45 * * * * /usr/bin/curl --anyauth --user username:password --silent --compressed http://example.com/cron.php