CS101 Notes Modules 82-181 by LGWT

82 : Networking and the Internet : Protection and Cures

1. Firewall :

A firewall is a network security device or system that monitors and controls incoming and outgoing network traffic, based on a set of security rules.

Firewall also used to protect individual computers rather than entire network or domain.

For Example if a computer is not being used as a web server , an email server , or a name sever , then a firewall should be installed at that computer to block all incoming traffic address to such applications. A properly installed firewall could block the message from these malicious clients.

Some Variation of the firewalls are designed specific purposes – an example being spam filters.

2. Spoofing :

Spoofing is a cyber security term referring to the practice of impersonating a legitimate entity or device to deceive others.

In Simple Word Spoofing is the act of pretending to be someone or something else to gain unauthorized access or trick a system or person.

3. Proxy Server :

A proxy server is an intermediary server that sits between a user's device and the internet. It receives user requests, forwards them to the destination server, and then returns the response back to the user. It can be used for privacy, security, content filtering, and caching

4. Auditing Software :

Auditing software is an administrator’s primary tool for identifying problems before they grow out of control.

Simple word Auditing software helps computer systems keep a record of who did what, when, and where — so that you can find out if something went wrong, who caused it, and how to fix it.

5. Antivirus Software :

Another means of defense against invasions via network connections is software called antivirus software, which is used to detect and remove the presence of known viruses and other infections. I hope you enjoyed these notes. I have written them in the simplest way for better understanding. Keep me in your prayers. Stay safe and Allah Hafiz

83 : Networking and the Internet : Encryption

Encryption :

A prime example in the secure version of HTTP known as HTTPS, which is used to most financial institution to provide customers with secure internet access to their accounts the backbone of HTTP is protocol system known as Secure Sockets Layer (SSL) , which was originally developed by Netscape to provide secure communication links between web clients and server.

1. Public Key Encryption :

Public key encryption, also known as asymmetric encryption, is a cryptographic technique that uses a pair of keys: a public key and a private key.

•  Public Key: Shared with everyone. Used to encrypt messages.
•  Private Key: Kept secret. Used to decrypt messages.

2. Certificate Authorities :

One Approach to resolving this problem is to established trusted internet sites, called certificates authorities.

A certificates is a package containing a party’s name and that party’s public key. Please Understand This Figure

Module 84

84. Networking and the Internet: Legal Approaches to Network Security

•  Enhancing the security of computer networking systems is to apply legal remedies.
•  Defining what is legal and what is illegal in different contexts.
•  Illegal actions may lead to punishment.

Two Issues

•  Making an action illegal does not stop the action.
•  International law: Illegal in one country and legal in another country.

US – Computer Fraud and Abuse Act

•  Passed in 1984 and has been revised many times.
•  Covers:

Worms and viruses Theft of information Many more related things; anything of value is covered.