Data Security

electronically as pdf Acrobat files. It is not normally necessary for students attending the course to print this file as complete sets of printed slides will be issued. ©2001 Antonia J. Jones. Permission is hereby granted to any web surfer for downloading, printing and use of this material for personal study only. Copyright permission is explicitly withheld for modification, re-circulation or publication by any other means, or commercial exploitation in any manner whatsoever, of this file or the material therein. Recommended texts: Other useful references: There are other books on coding theory in the library by R. W. Hamming, J. van Lint and R. J. McEliece. These are more advanced than the recommended texts. The outstanding modern cryptographic reference is B. Schneider. Fills in many aspects of the present course and goes on to discuss mail and internet security. The classic 1,200 page definitive story of cryptography up to the late 1950's is: A recent very interesting account including the history of RSA and PGP and a non-technical discussion of quantum cryptography is: Note: entries marked with an asterisk (*) will not be examinable and will be discussed briefly as time permits. Security Computer security involves all aspects of data security including Physical security. Protection of the equipment and data against accidental or deliberate damage, including theft. Logical security. Protection of the software and hardware against accidental or deliberate modification. Correctness. Correctness of programs means ensuring that the programs do what they are supposed to do under all circumstances. Operating system security. Really part of logical security but practical security considerations make this a specialised discipline in its own right. In this course we shall look at data security and logical security in general but not operating system security. We shall also not cover physical security nor the problems of proving correctness of programs. 7 Encrypted error corrected noisy channel Encrypted error corrected noisy channel Encrypted channel Figure 1 Different types of communication channels. After a brief discussion of general principles of security we shall consider methods of protecting data, which is being stored or transmitted, from accidental corruption. A standard method for achieving this is by the use of error detecting and error correcting codes. Later we shall consider the different problem of protecting the confidentiality of data, i.e. of ensuring that it can only be read by the people or machines for whom it is intended. 8 This …