If you need to submit a set of files in a hierarchical directory structure, you must first use tar to combine them all into one archive which you can then submit as a single file. Repeat submissions for the same assignment get treated as independent submissions. Only the last one will be inspected, so make sure that it is complete and does not rely on files in previous submissions for the same assignment. Once you have logged into one of the above machines, you can do your homework assignment. Selected Papers Complete trust is not axiomatic since different parties have conflicting agendas.
Mutual protection is effected through access control .
Permission is granted to a principal that is recognized via authentication . Acceptable behaviour is described by a security policy . Gaps between the formal model and the implemented access control allow attacks. These may be against host security , network security , or physical security . The system can be protected by intrusion detection .