Encryption
Encryption has long been used by militaries and governments to facilitate secret communication. It is now commonly used in protecting information within many kinds of civilian systems. For example, the Computer Security Institute reported that in 2007, 71% of companies surveyed utilized encryption for some of their data in transit, and 53% utilized encryption for some of their data in storage. Encryption can be used to protect data "at rest", such as information stored on computers and storage devices (e.g. USB flash drives). In recent years, there have been numerous reports of confidential data, such as customers' personal records, being exposed through loss or theft of laptops or backup drives; encrypting such files at rest helps protect them if physical security measures fail. Digital rights management systems, which prevent unauthorized use or reproduction of copyrighted material and protect software against reverse engineering (see also copy protection), is another somewhat different example of using encryption on data at rest.
Column level encryption
Generally, when data are being collected and stored as records, those records will appear in a tabular format in rows in the database with each rows logging specific attributes. Some data can be more sensitive than others, for example, data of birth, social security number, home address, etc., which can act as a personal identification. In order to ensure that these private information is transferred and stored securely, data goes through encryption, which is the process of encoding plaintext into ciphertext. Non-designated readers or receivers will not be able to read the data without the decryption key. Another example to illustrate this concept is, given a database stores client's phone numbers. The set of phone numbers will appear to most readers as gibberish alphanumerical text with a mix of symbols, totally useless to those who do not have access privilege to view the data in plaintext (original form).