Producing one time password for mobil devices and testing its security

Today fast-growing technology changes human life in many respects. Especially developments in information technologies greatly change many practices of today?s human being such as business life, communication, knowledge acquisition by means of the speed and also efficiency it provides. Improved computer systems and especially the Internet network enables almost all sorts of connection on a global basis. In this developing technology, the subject of separation of authorized and unauthorized users who accessed to computer systems has gained great important especially with the spread of Internet-based applications. For example; people who are using internet banking, access to bank system by user name and password. When these users use user name and static password, the computer hackers may take these information and then they may make illegal transactions with these information by accessing personal bank account. OTP (One Time Password) one time password systems enter here and provides the possibility to use a different password by the user to access to the system for every time. In the scope of the thesis, one time password software which is generated for mobile devices, eliminates the above-mentioned disadvantages for communication environment, and produces the maximum level for the security of the user.