Database security

Database security

Database security is the system, processes, and procedures that protect a database from unintended activity. Unintended activity can be categorized as authenticated misuse, malicious attacks or inadvertent mistakes made by authorized individuals or processes. Database security is also a specialty within the broader discipline of computer security.
Traditionally databases have been protected from external connections by firewalls or routers on the network perimeter with the database environment existing on the internal network opposed to being located within a demilitarized zone. Additional network security devices that detect and alert on malicious database protocol traffic include network intrusion detection systems along with host-based intrusion detection systems.

Database security is more critical as networks have become more open.
Databases provide many layers and types of information security, typically specified in the data dictionary, including:
• Access control
• Auditing
• Authentication
• Encryption
• Integrity controls

Database security can begin with the process of creation and publishing of appropriate security standards for the database environment. The standards may include specific controls for the various relevant database platforms; a set of best practices that cross over the platforms; and linkages of the standards to higher level polices and governmental regulations.

Protecting the data in our enterprise databases is extremely important. At one level we have the database authorization and roles built directly into the DBMS products, GRANT and REVOKE statements that can be used to authorize access to database objects, resources and statements. This level of database security is important, but is by no means sufficient. And many DBMS products are evolving to deliver additional security.

For example, DB2 offers multi-level security, which gives the ability to protect data and authorize use of data at the row level. A multilevel security system allows the protection of data based on both traditional discretionary access controls, and controls that check the sensitivity of the data itself through mandatory access controls. These mandatory access controls are at the heart of a multilevel security environment, which prevents unauthorized users from accessing information at a classification they are not authorized to, or changing the classification of information they do have access to. These mandatory access controls provide a way to segregate users and their data from other users and their data regardless of the discretionary access they are given though access lists, etc. The primary arena where multilevel security is valuable is government agencies that need a security environment that keeps information classified and compartmentalized between users.

Another method to better secure database data is through encryption. But there are problems with encrypting database data. First of all, encryption is supported differently in every DBMS. Also, performance is an issue. It takes CPU cycles to encrypt and decrypt that data, so is security more important than rapid access? Even more problematic is indexed access. If indexed columns are encrypted, the DBMS will sort the encrypted strings -- and they won't match the real, unencrypted data.

There are actually two types of encryption with respect to database data - encryption at rest and encryption over the wire. Basically, encrypting the database data on disk. But there are also encryption products that will encrypt the data before it is sent across the network and decrypt it once it is received. Encryption over the wire is helpful to prevent surreptitious access to data as it flies throughout your network, but it won't help combat thieves who target the database files on disk.
Another burgeoning field is database access auditing. This type of solution monitors database activity (INSERT, UPDATE, DELETE, and even SELECT) and reports on who is accessing and changing what data when. Such information can be very helpful to ensure that only appropriate personnel are accessing appropriate data within the database. Such solutions can help to track the activity of privileged users (such as SYSADMs). And they can be invaluable in terms of being in compliance with regulations such as PCI-DSS and HIPAA.

Taking things yet another step further, auditing data can be achieved in an active manner - - let’s call it data trend monitoring. This type of solution monitors all database requests as they happen and discovers access patterns and trends. Configure policy-based access and control such that invalid data requests and/or modifications can be stopped and alerts can be generated when such actions are attempted. Trends can be monitored so that any behavior outside of the norm can be highlighted and investigated. This can be important, for example, to watch for suspect activity initiated by authorized users. Some analysts suggest that such activity is more pervasive and potentially damaging to data than external attacks. And it can be very hard to detect.