1. Security

2. Issues Regarding Database Security
Legal and ethical issues regarding the right to access certain information. For instance some information is private and can't be legally accessed by unauthorized persons.
Policy issues at the governmental, institutional, and corporate levels. Some information is kept secret even when not required by law.
System-related issues: Where should security be enforced (and the physical level, OS level, DBMS level, or higher)?
The need for multiple security levels, where different persons have the ability to access different data, but data should not be transferable across security levels.

3. Threats
Loss of integrity: Modification of the data within a database must be protected from accidental or malicious changes. If the data's integrity (truthiness) is broken, you can't use your data anymore.
Loss of availability: If your database is inaccessible, it ceases to be useful. It is important that the database is protected from attacks that threaten its ability to function.
Loss of confidentiality: The data needs to be protected from people who don't have the right to access it. Unauthorized disclosure of information can lead to violations of the Data Privacy Act, loss of corporate secrets to the jeopardization of national security.

4. Control Measures
There are 4 main mechanisms (control measures) to provide security for databases:
Access Control: Only allowing authorized users to access specific parts of the database
Inference Control: Ensuring that individual privacy is not violated when revealing aggregate data
Flow Control: Ensuring that information isn't transmitted via covert channels across security levels
Encryption: Ensuring that data at rest and in transit is not viewable (nor modifiable) by unauthorized parties.

5. Do all databases require security measures?
1. No, only databases containing sensitive information.
2. No, the data can be secured through other means (controlling access to the database itself)
3. Yes, all data should be secured, especially from modification.
4. Yes, L33T h4x0r's want to pwn me

6. Sensitive Data
Sensitivity of data is a measure of the importance assigned to the data by its owner for the purpose of denoting its need for protection.
If a database doesn't contain sensitive information, its security doesn't matter.
If a database contains only sensitive information, it needs to be secured.
The tricky case is when a database contains both sensitive and not sensitive data. In this circumstance, access control is needed to allow for different users to have different capabilities.

7. Factors making data sensitive
Inherently sensitive: the value of the data itself may be so revealing/confidential that it needs to be protected (e.g. a person's salary or who has an STD).
From a sensitive source: The source of the data may indicate a need for secret (e.g. a police informant / tattle-tale).
Declared sensitive: The owner may explicitly declare it sensitive (e.g. secret Coke recipe).
A sensitive attribute / record: A particular column / row of a table may be made sensitive (e.g. reviewer identity or classes of crimes)
Sensitive in relation to previously disclosed data: Some data may not be sensitive by itself, but when combined with other data, reveals sensitive information. My anarchist pseudonym and the posts under it aren't sensitive, but the connection between my real identity and my pseudonym is.