Web applications allow legitimate website visitors to submit and retrieve data to/from a database over the Internet. Web applications are used for collecting information, and analyze it. Sql injection is one of the most dangerous attacks which are used to access database without authentication. SQL is used to retrieve; insert data to/from the database .Using sql command make it a malicious code for attack at authentication section of front end of web application and send to the server. This process is known as SQL injection authorization attack.SQL injection authorization attack easily gets entry in the database and catches all information from database. This paper illustrates the method for prevention from SQL injection authorization attack i.e. recursively authentication or double authentication. Automatically authentication will increase. We are going to implement recursive method on web based program using string inputs and its ASCII value General Terms: Web application, authentication, and Increase authentication Keyword: ASCII, recursive authentication, double authentication