tailieunhanh - Handbook of Applied Cryptography - chap1

Cryptography has a long and fascinating history. The most complete non-technical account of the subject is Kahn’s The Codebreakers. This book traces cryptography from its initial and limited use by the Egyptians some 4000 years ago, to the twentieth century where it played a crucial role in the outcome of both world wars. Completed in 1963, Kahn’s book covers those aspects of the historywhichwere most significant (up to that time) to the development of the subject. The predominant practitioners of the art were those associated with the military, the diplomatic service and government in general. Cryptography was used as a tool to protect national secrets and strategies | This is a Chapter from the Handbook of Applied Cryptography by A. Menezes P. van Oorschot and S. Vanstone CRC Press 1996. For further information see hac CRC Press has granted the following specihc permissions for the electronic version of this book Permission is granted to retrieve print and store a single copy of this chapter for personal use. This permission does not extend to binding multiple chapters of the book photocopying or producing copies for other than personal use of the person creating the copy or making electronic copies available for retrieval by others without prior permission in writing from CRC Press. Except where over-ridden by the specihc permission above the standard copyright notice from CRC Press applies to this electronic version Neither this book nor any part may be reproduced or transmitted in any form or by any means electronic or mechanical including photocopying microhlming and recording or by any information storage or retrieval system without prior permission in writing from the publisher. The consent of CRC Press does not extend to copying for general distribution for promotion for creating new works or for resale. Specihc permission must be obtained in writing from CRC Press for such copying. @1997 by CRC Press Inc. Chapter Overview of Cryptography Contents in Brief Introduction. 1 Information security and cryptography. 2 Background on functions. 6 Basic terminology and concepts. 11 Symmetric-key encryption. 15 Digital signatures. 22 Authentication and identification. 24 Public-key cryptography. 25 Hash functions. 33 Protocols and mechanisms. 33 Key establishment management and certification. 35 Pseudorandom numbers and sequences. 39 Classes of attacks and security models. 41 Notes and further references. 45 Introduction Cryptography has a long and fascinating history. The most complete non-technical account of the subject is Kahn s The .