Lecture3 of Computing SecurityI 2018-2019

Lecture 3 Outlines:
• Security Mechanisms
• A Model for Network Security
• Basic Concepts & terms of Cryptography
1. Security Mechanisms
It is process (or a device including such a process) that is designed to detect, prevent, or recover from a security attack. The mechanisms are divided into:
1.1 Specific Security Mechanisms
that are implemented in a specific protocol layer, such as TCP or an application-layer protocol, in order to provide some of the OSI security services; such as:
Encipherment: The use of mathematical algorithms to transform data into a form that is not readily intelligible.
Digital Signature: Data appended to, or a cryptographic transformation of, a data unit that allows a recipient of the data unit to prove the source and integrity of the data unit and protect against forgery (e.g., by the recipient).
Access Control: A variety of mechanisms that enforce access rights to resources.
Data Integrity: A variety of mechanisms used to assure the integrity of a data unit or stream of data units.
Authentication Exchange: A mechanism intended to ensure the identity of an entity by means of information exchange.