System Network Security - E-Commerce - Lecture Slides, Slides of Fundamentals of E-Commerce

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System and Network

Security Overview

What is network security about?

It is about secure communication
What do we mean by secure communication?
Everything is connected by the Internet
We will often use Alice and Bob
Alice is on a vacation and wants to send a commandto her assistant—Bob—or just a computer tocontrol the nuclear power plant, how can she dothat?

Other examples

Alice sends Bob some sensitive information viaInternet
Network manager remotely changes someAccess Control Lists (intercepts, impersonation)
On-line stock trading, customer denies that shehas sent the order

Cryptography

Cryptography allows us to disguise data so thateavesdroppers gain no information fromlistening
Cryptography also allows us to createunforgettable message and detect if it has beenmodified in transit: a digital signature is oftenused for this purpose—a magic number

Two kinds of security

Computer security
Network security

Vulnerabilities of comp sys

attacks on hardware
attacks on software
deletion, modification (Trojan horse,trapdoor/backdoor, covert channel), infectionthrough computer virus, theft, copying
attacks on data
compromising secrecy & integrity
attacks on other resources
storage media, time, key people

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Failures of security mechanisms

Failure to understand the threat model
Failure to understand what a mechanismprotects against and what it does not
Bad design
Implementation fault
Misconfiguration
Bad interaction with other parts
Bad user interface