Implementation of one time password with ARM processor

The application of one time passwords (OTP) is much safer than static passwords for the systems which give special importance to authentication. The passwords employed by the user cannot be used again after the authentication approval. Authentication is ensured by providing a new password, which is different from the earlier ones, for each time the user wants to access to the system. These passwords are also called as ?disposable passwords?. While the passwords are being generated, it should be taken into consideration that they may be attacked. Therefore, password-generating systems are required to use a secure hash function.At present, HOTPs (HMAC One Time Password), which are produced as HMAC (Hash Message Authentication Code) based, are used in order to create a unique OTP (One-Time-Password) [1]. In the HMAC-based HOTP algorithm, a secret common key is shared by client/server and starting counter is launched synchronically. The secret common key and the value of counter are sent to hash function. The message that comes with hash function is summarized. The output of hash function, which returns as HMAC result, is truncated and the HOTP values are acquired. In this study, besides the MD5 and SHA-1 classic hash functions, by using the hash function created by chaotic map, more secure HOTPs against the attacks have been tried to be obtained.In the HOTP authentication mechanism, there are two sides in interaction. In this thesis, one HOTP authentication which can work on server and one HOTP generator software which can work on the Mini?2440 product from the family of ARM9 has been developed. These softwares, working in synchronization, produce one-time-use password and verify that password.