Data Security

• the protection of data from accidental or malicious modification, destruction, or disclosure (FIPS);

• the science and study of methods of protecting data in computer and communications systems against unauthorized disclosure, transfer, delay, modifications, or destruction, whether accidental or intentional.

To put it rather more concisely, data security means providing the users of your data with the data that you intend them to have, and with that data only, at the time that you mean them to have it.