On Protocols for Information Security Services

Now-a-days, organizations are becoming more and more dependent on their information systems due to the availability of high technology environment. Information is also treated as vital like other important assets of an organization. Thus, we require Information Security Services (ISS) protocols to protect this commodity. In this thesis, investigations have been made to protect information by developing some ISS protocols. A key management protocol, which stores one-way hash of the password at the server, instead of storing plaintext version of password has been explained. A unique asymmetric cryptosystem for encrypting large messages has been described, which is not only efficient but also secure as compared to other asymmetric cryptosystems.Blind Signature Schemes (BSS) facilitate a requester to obtain signature from a signer on any document, in such a way that the signer can't know anything about the message that is being signed. Four BSS have been described which are based on Elliptic Curve Discrete Logarithm Problem (ECDLP).A remote user authentication scheme based on ECDLP has been described.