1. Chapter Name
September 98
Security
by Adrienne Watt

2. Security
The protection of data against unauthorized disclosure, alteration, or destruction. GENERAL CONSIDERATIONS: - Legal, social, and ethical aspects - Physical controls - Company policies - Operational concerns - Hardware controls - Operating system security - Data ownership

3. DATA SECURITY
Threat: Any situation or event, whether intentional or unintentional, that will adversely affect a system and consequently an organization. Theft and fraud Unauthorized amendment of data Program alteration Wire tapping Illegal entry by hacker Loss of confidentiality (secrecy) Blackmail Illegal Entry by hacker Inadequate or ill-thought out procedures that allow confidential output to be mixed with normal output. Staff shortage or strikes Inadequate staff training

4. DATA SECURITY
Loss of privacy Inadequate staff training Viewing unauthorized data and disclosing it Loss of integrity Electronic interference and radiation Fire (electrical fault/lightning strike) Loss of availability Flood

5. DATA SECURITY Hardware failure resulting in a corrupt disk.
The extent of loss depends upon factors such as the impact of the threat balanced against countermeasures and contingency plans.
 e.g.
Hardware failure resulting in a corrupt disk.
Does alternative hardware exist that can be used?
Is this alternative hardware secure?
Can we legally run our software on this hardware?
If no alternative hardware exists, how quickly can problem be fixed?
When were the last backups taken of the database and log files?
Are the backups in a fireproof safe or offsite?
If the most current database needs to be recreated by restoring the backup with the log files, how long will it take?
Will there by any immediate effects on our clients?
If we restore the system, will the same or similar breach of security occur again unless we do something to prevent it from happening?
Could our contingency planning be improved?

6. COMPUTER BASED CONTROLS
The security of a DBMS is only as good as that of the operating system. Authorization: The granting of a right or privilege which enables a subject to legitimately have access to a system or object. Authentication: A mechanism by which a subject is determined to be the genuine subject that they claim to be. Logon Passwords

7. COMPUTER BASED CONTROLS
The types of privileges that an authorized subject may be given include:
Use of specific named databases
Selection or retrieval of data
Creation of tables and other objects
Update of data (may be restricted to certain columns)
Deletion of data (may be restricted to certain columns)
Insertion of data (may be restricted to certain columns)
Unlimited result set from a query (that is, a user is not restricted to a specified number of rows)
Execution of specific procedures and utility programs
Creation of databases
Creation (and modification)of DBMS user identifiers and other types of authorized identifiers
Membership of a group of users, and consequent inheritance of the group’s privileges

8. Ownership and Privileges
Different ownership for different objects
Ownership of objects gives the owner all appropriate privileges on the objects owned.
Newly created objects are automatically owned by their creator who gains the appropriate privileges for the object.
Privileges can be passed on to other authorized users.
DBMS maintains different types of authorization identifiers. (users and groups)

9. DBMS SUPPORT The above policy decisions are enforced by the dbms
DISCRETIONARY CONTROL
  - privileges or authorities on different objects
- policy decisions
- flexible
  Examples:
  GRANT SELECT ON S TO CHARLEY
  GRANT SELECT, UPDATE (STATUS, CITY) ON S TO JUDY
  GRANT ALL PRIVILEGES ON S TO TED
  GRANT SELECT ON P TO PUBLIC
  GRANT DBA TO PHIL
  REVOKE SELECT ON S FROM CHARLEY
  REVOKE UPDATE ON S FROM JUDY
The above policy decisions are enforced by the dbms
The systems catalog contains:
 - Sysuserlist
 - Sysauthlist

10. DBMS SUPPORT
MANDATORY CONTROL - each object has a classification level (top secret, confidential, etc.) - each user has a clearance level - not supported by any current DBMS - very rigid

11. DBMS SUPPORT
Views: Can be used to represent only the data which is relevant to a user, by effectively hiding other fields.
Backing-up: The process of periodically taking a copy of the database and journal (and possibly programs) onto offline storage media. Various depending on size of data
Journaling: The process of keeping and maintaining a journal or log of all changes made to the database to enable recovery to be undertaken effectively in the event of a failure.
must be enabled
copies of journal on other disks
record all security violations

12. DBMS SUPPORT
Checkpointing: The point of synchronization between the database and the transaction log file. All buffers are force-written to secondary storage.
Encryption: The encoding of the data by special algorithm that renders the data unreadable by any program without the decryption key.
encrypt/decrypt
degradation of performance

13. Associated Procedures
To ensure controls are effective:
 Authorization and Authentication:
Password lengths
Password duration
Backup:
 Determine procedures
Frequency
Recovery:
Determine procedures

14. Audit Check that all proper controls are in place.
Ensuring accuracy of input data
Ensuring accuracy of data processing
Prevention and detection of errors during program execution
Properly testing and documenting program development and maintenance
Avoiding unauthorized program alteration
Granting and monitoring access to data
Ensuring documentation is up to date

15. Non-Computer Based Controls
Establishment of a Security Policy:
The area of the business it covers
Responsibilities and obligations of employees
Procedures that must be followed
Establishment of a Contingency Plan:
Who the key personnel are and how they can be contacted
If key personnel are unavailable, a list of alternative personnel and how they can be contacted.
Who decides that a contingency exists and how that is decided
The technical requirements of transferring operations elsewhere
Additional equipment needed
Will communication lines need to be installed
Operational requirements of transferring operations elsewhere
Staff needed to work away from home
Staff needed to work unusual hours
Staff will need to be compensated
Any outside contacts who may be help, for example:
Equipment manufacturers
Whether any insurance exists to cover the situation

16. Non-Computer Based Controls
Secure Positioning of Equipment
Restrict access to printers especially if used for sensitive information
Locate computer terminals sensibly if likely to display sensitive information
Site cabling to avoid damage
Secure Data and Software
Ensure a secure storage area is available on-site
Have an off-site secure storage area
Index all the material

17. Non-Computer Based Controls
Physical Access Controls:
  Internal Controls: Govern access to areas within a building
  External Controls: Govern Access to the site
Emergency Arrangement
 Cold Site
Warm Site
Hot Site
PC Security
Viruses

18. Statistical Databases
A collection of confidential information on individuals
 Preventing queries from operating on only a few database entries
Randomly adding in additional entries to the original query result set, which produces a certain error but approximates to the true response
Using only a random sample of the database to answer the query
Maintaining a history of the query results and rejecting queries that use a high number of records identical to those used in previous queries.

19. Risk Analysis Establish a Security Team
Define the scope of the analysis and obtain system details
Identify all existing countermeasures
Identify and evaluate all assets
Identify and assess all threats and risks
Select countermeasures, undertake a cost/benefit analysis and compare with existing countermeasures
Make recommendations
Test security system

20. Data Protection and Privacy Laws
Privacy: Concerns the right of an individual not have personal information collected, stored and disclosed either willfully or indiscriminately.
Data Protection: The protection of personal data from unlawful acquisition, storage and disclosure, and the provision of the necessary safeguards to avoid the destruction or corruption of the legitimate data held.
Since the 1970s different countries have instituted various laws that deal with these issues.