ITM 820 Study Guide - Midterm Guide: Data Link Layer, Replay Attack, Chmod

• School: Ryerson University
• Department: Information Technology Management
• Course: ITM 820
• Professor: Debashish Roy

Document Summary

Difference between encoding & encryption, encoding is public. Transforms data into another format using a scheme that is publicly available so that it can easily be reversed. Purpose of encoding is to transform data so that it can be properly (and safely) consumed by a different type of system: encryption is private. Transforms data into another format in such a way that only specific individual(s) can reverse the transformation. Purpose of encryption is to transform data in order to keep it secret from others: probable base for the symbols, base is 10. Base for 4 is 5: base for binary is 2. 2^8 1 which is 255: what is the largest 6-bit number, 2^6 1 = 63. To get the largest # you must do 2^n 1. Policy says what you are supposed to achieve: incentives. The motive that the people guarding and maintaining the system have to do their job properly: mechanism.