The security of database is very important as data is the most valuable asset in the modern environment. Various security methodologies are available to secure databases. Most of the available methodologies focus on access control of the database, but there may be situations when someone intentionally or accidentally break or bypass the access control mechanism of the database and hence the confidentially of the database could be compromised. Various methods are available to preserve the confidentially of the database in those situations. The best solution in this case is encryption. Various Researchers proposed different methods by which the database encryption can be enforced and the content of database is encrypted and decrypted efficiently. All Encryption techniques available till date converts plain text into cipher text but the length of both will be same, this is a serious shortcoming of available cryptographic approach for example some attacker can guess the plain text by accessing the length of cipher. In this paper we elaborate the use of database encryption to protect the database content. We propose a User supplied Key based authentication which generates the cipher of different length in comparison to plain text. By the use of this approach database can be protected against various kind of vulnerabilities.