One time password generator

With the widespread of technology, use of internet has increased a lot. Many applications have been a part of our daily lives such as, e- government applications, electronic commerce, Internet banking and bill payment transactions. The user name and password is used for authentication in electronic media process. However, along with evolving cyber-attacks, now classic authentication process is insufficient for the security of critical data. So, many applications are preferred a two-level authentication process in the last period. Two-level authentication process is required to be entered random string of characters after the input user name and his password in each the verification process. One Time Password (OTP) which is fixed length strings to perform authentication in electronic media is used as a one-time. They are called in disposable or throwaway password. This character length and type is vary for applications. OTP production was studied in this thesis. OTP produced in various ways but the most common approach is to use pattern based on the hash function. Hash functions for a message of arbitrary length value produces a summary of a certain length. In this thesis, Keccak digest algorithm was used for the production of OTP. This algorithm has been selected as the latest standards for hash algorithm in October 2012 by NIST (National Instute of Standards and Technology). This algorithm is preferred because it is faster and safer than the others. OTP production methods based on hash functions is called HMAC (Hashing-Based Message Authentication Code) structure. In these structures, the key value is using with the hash function to generate the HMAC value. Produced OTP value is based on the HMAC value. In this application, the length of the value OTP was the eight characters to be useful in practice.