Ceph Node Resilience / Or Other Datastores

I would like to know how to secure Ceph nodes. What can an attacker do with access to a node? I am looking for a solution where a node compromise (full access) cannot affect the data structure. Is this possible with Ceph? Is there a better file distribution tool for archiving resilience datastores? I am basically looking for something like BitTorrent distribution resilience (if a peer/node is malicious or fails does not matter) but with a convenient way to manage, private (not full blown P2P) and S3 API. Any ideas?