1. Introduction: Globalization and advances in the Internet and information technologies have opened the way to new means of communication. Countries separated by oceans united thanks to the Internet and the Web. Gone are the days when data and information were stored on paper. Now everything is stored electronically, which is more reliable and secure. As data multiplies, security issues also multiply at the same speed, raising concerns about its security. Although regulatory bodies have come up with strict guidelines and policies with constant modifications to keep data and information secure and prevent it from falling into the wrong hands, data breaches continue to occur, exposing people and businesses at great risk. This is the time when data needs to be secured at the root level and data encryption scales appropriately to accomplish this task and protects data at rest. This article focuses on database encryption for database security, the different methods and levels of database encryption, and its advantages over other data protection methods. It also discusses performance issues associated with data encryption and best practices for minimizing the performance overhead on the database server due to encryption.2. Database Security – Encryption: Database security secures data in a centralized database against compromises of its confidentiality, integrity and availability. This is achieved through various information security controls or processes, including access control, authentication, auditing, integrity checks, backups and encryption. The databases were protected to a higher level through network security measures such as firewalls and systems......paper......doi:10.1109/TPDS .2013.1543. Sharma, M., Chaudhary, A. and Kumar, S. (2013) Query processing performance and searching on encrypted data using an efficient algorithm. International Journal of Computer Applications 62(10), 4, 5-8. do I: arXiv:1308.4687v1 [cs.DB]4. Oracle Company. (2012). Best practices for transparent data encryption. Retrieved from http://www.oracle.com/technetwork/database/security/twp-transparent-data-encryption-bes-130696.pdf5. Hsueh, S. Microsoft Corporation. (2008). Database encryption in SQL Server 2008 Enterprise Edition. Retrieved from http://technet.microsoft.com/enus/library/cc278098(v=sql.100).aspx6. Keshavamurthy, B., Khan, A. and Toshniwal, D. (2013). Mining privacy-preserving association rules on distributed databases using a genetic algorithm. Neural Computing and Applications, 22351-364. doi:10.1007/s00521-013-1343-9.