【正文】 and collaboration Developments in Data and Applications Security: Multilevel Secure Databases I ? Air Force Summer Study in 1982 ? Early systems based on Integrity Lock approach ? Systems in the mid to late 1980s, early 90s ., Seaview by SRI, Lock Data Views by Honeywell, ASD and ASD Views by TRW Prototypes and mercial products Trusted Database Interpretation and Evaluation of Commercial Products ? Secure Distributed Databases (late 80s to mid 90s) Architectures。 Simulation of distributed transaction management and concurrency control algorithms。 Security constraint processing during query, update and database design operations。 Distributed object systems security。 Secure multimedia data management ? Secure Transactions (1990s) Single Level/ Multilevel Transactions。 realtime data mining ? Secure knowledge management Protect the assets and intellectual rights of an anization ? Information assurance, Infrastructure protection, Access Control Insider cyberthreat analysis, Protecting national databases, Rolebased access control for emerging applications ? Security for emerging applications Geospatial, Biomedical, ECommerce, etc. ? Other Directions Trust and Economics, Trust Management/Negotiation, Secure Peertopeer puting, Coalition Data and Policy Sharing Export Data/Policy Component Data/Policy for Agency A Data/Policy for Federation Export Data/Policy Component Data/Policy for Agency C Component Data/Policy for Agency B Export Data/Policy Other topics of Interest ? Secure Cloud Computing ? Mobile code security ? Vulnerability Analysis ? Infrastructure security Power grid ? Healthcare Security ? Financial Security Access Control ? Discretionary Access Control in Relational Databases ? Mandatory Access Control in Relational Databases Security Constraints ? Types of Access Control Inference problem, Rolebased, Temporal, Usage ? Access Control in Other Databases Objects, Federated ? Current Trends in Access Control Date Warehousing, Semantic Web, Privacy Control ? Next Steps in Access Control Access Control in Relational Databases: 1975 Present ? Access Control policies were developed initially for file systems ., Read/write policies for files ? Access control in databases started with the work in System R and Ingres Projects Access Control rules were defined for databases, relations, tuples, attributes and elements SQL and QUEL languages were extended ? GRANT and REVOKE Statements ? Read access on EMP to User group A Where 30K and Security Query Modification: ? Modify the query according to the access control rules ? Retrieve all employee information where salary 30K and Dept is not Security Query Modification Algorithm ? Inputs: Query, Access Control Rules ? Output: Modified Query ? Algorithm: Given a query Q, examine all the access control rules relevant to the query Introduce a Where Clause to the query that negates access to the relevant attributes in the access control rules ? Example: rules are John does not have access to Salary in EMP and Budget in DEPT ? EMP (E, Ename, Salary, D), DEPT (D, Dname, Budg, Mgr) Query is to join the EMP and DEPT relations on Dept ? Modify the query to Join EMP and DEPT on Dept and project on all attributes except Salary and Budget Output is the resulting query Mandatory Access Control (MAC) in Databases: 1982 Present ? Bell and LaPadula Policy adapted for databases Read at or below your level and Write at your level。 individually each attribute can be accessed by John ? Release constraint: After X is released Y cannot be accessed by John ? Aggregate Constraints: Ten or more tuples taken together cannot be accessed by John ? Dynamic Constraints: After the Mission, information about the mission can be accessed by John Enforcement of Security Constraints User Inte