The Engineering of Access Control Mechanisms in Physics Data Bases

A model is presented for engineering the user interface for large data base systems in order to maintain flexible access controls over experimental and other physics data. Several examples of its use are given. The model is independent of both machine and data base structure,, Access control is based on sets of procedures called form&tries O The decision on whether a user can read, write, update, etc O , data is controlled by programs (not merely bits or tables of data) which can be completely independent of the contents or location of raw data in the data base. The decision to grant or deny access can be made in real time at data access time, not only at file creation time as has usually been the case in the past. Indeed, the model presented does not make use of the concept of “files”, though a specific interpretation of the model may do so. Access can be controlled at arbitrarily low levels, including the data field level and the bit level. Each element of raw data need appear only once, thus allowing considerable savings in memory and in maintenance effort over previous file-oriented systems. Access controls for physics data banks of the type presented herein are of special interest to regional computing centers or other centers with many independent users O