الفهرس 
PRINCIPLES OF CRYPTOLOGYOnly 14 pages are availabe for public view
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Abstract
Cryptography has a long and fascinating history. Cryptography was used as a tool to protect national secrets and strategies. The proliferation of computers and communications systems in the 1960s brought with it a demand from the private sector for means to protect information in digital form and to provide security services.
Authentication is one of the most important of all information security objectives.• Authentication is a term which is used (and often abused) in a very broad sense. By itself it has little meaning other than to convey the idea that some means has been provided to guarantee that entities are who they claim to be, or that information has not been manipulated by unauthorized parties. Authentication is specific to the security objective which one is trying to achieve.
A cryptographic primitive which is fundamental in authentication, authorization, and nonrepudiation is the digital signature. The purpose of a digital signature is to provide a means for an entity to bind its identity to a piece of information. The process of signing entails transforming the message and some secret information held by the entity into a tag called a signature.
Authentication and key establishment are fundamental building blocks for securing electronic communication. Cryptographic algorithm for encryption and integrity cannot perform their function unless secure keys have been established and the users know which parties share such keys.
Therefore new digital signature schemes that are secure and provide authentication, authorization, and nonrepudiation are needed. These are; the new Ong, Schnorr and Shamir signature scheme and the proposed digital signature system signature scheme. Authenticated, secure and less complexity protocol is need for key establishment. These are our thesis aims