TCSS 431: Network Security

Class Meeting 2a: Introduction to Network Security

Joe McCarthy

Network Security close to home

Hacked Yahoo mail accounts

Subject: hi how are you?Date: Sat, 23 Oct 2010 00:43:49 -0700 (PDT)From: * <*@yahoo.com>To: *@gmail.com, *@nokia.com, *@stanford.edu, *@baylegal.org …

http://villarentalbyowner.com/index0314.php

Hacked Yahoo mail accountsSubject: this account has a virus - feel free to block itDate: Tue, 19 Oct 2010 15:46:27 -0700 (PDT)From: * <*@yahoo.com>To: * <*@gmail.com>

Dear friends and colleagues, Some time earlier this year, my yahoo email account "contracted" a virus. As a result of it, my address book is being used to send spam emails to all of you which appear as if they are coming from me. They typically contain links to web sites, promotions, meds, etc. I am very sorry about this annoying cycle. I have tried to correct the problem through Yahoo's customer support. There doesn't seem to be any immediate remedy, as the emails don't originate from me any more. All I can hope is that this eventually wears itself off. Please feel free to block *@yahoo.com. I am switching to using *@gmail.com as my private email. I am also available at *@nokia.com. Thanks,*

A few words (& images) aboutPassword Security

http://blogs.computerworld.com/17547/a_formula_approach_to_generating_passwords

… some combination of upper and lowercase characters as well as numbers and a few ascii characters at least 13 characters in length … (Example: tH3w0rldi5round!1!)

http://www.passwordmeter.com/

Textbook update

Network Security: Private Communication in a Public World, 2/EKaufman, Perlman & SpecinerPrentice Hall, 2003

Counter Hack Reloaded: A Step-by-Step Guide to Computer Attacks and Effective Defenses, 2/ESkoudis & ListonPrentice Hall, 2006

Another perspectiveon Network Security

Network Security Essentials: Applications and Standards, 4/EWilliam Stallings

ISBN-10: 0136108059ISBN-13: 9780136108054

Publisher: Prentice HallCopyright: 2011Format: Paper; 432 ppPublished: 03/12/2010

http://williamstallings.com/NetSec/NetSec4e.html

The Security Requirements Triad

Computer SecurityThe protection afforded to an automated information system in order to attain the applicable objectives of preserving the integrity, availability and confidentiality of information system resources (includes hardware, software, firmware, information/data, and telecommunications)

Security Requirements

• Confidentiality– Preserving authorized restrictions on information access

and disclosure, including means for protecting personal privacy and proprietary information.

• Integrity– Guarding against information modifications or destruction,

including ensuring information non-repudiation and authenticity.

• Availability– Ensuring timely and reliable access to and use of

information

Security Attacks, Mechanisms & Services

• Security Attack– Any action that compromises the security of

information• Security Mechanism– A process / device that is designed to detect,

prevent or recover from a security attack.• Security Service– A service intended to counter security attacks,

typically by implementing one or more mechanisms.

Threats & Attacks

… but threat and attack used nearly interchangeably

Security Threats / Attacks

… …

Security Threats / Attacks

Passive Attacks

Active Attacks (1)

Active Attacks (2)

Security Services (X.800)• Authentication

– The assurance that the communicating entity is the one it claims to be• Access Control

– The prevention of unauthorized use of a resource • who can have access to a resource,• under what conditions access can occur, • what those accessing the resource are allowed to do

• Data Confidentiality– The protection of data from unauthorized disclosure

• Data Integrity– The assurance that data received are exactly as sent by an authorized entity (i.e.,

contains no modification, insertion, deletion or replay).• Non-Repudiation

– Provides protection against denial by one of the entities involved in a communication of having participated in all/part of the communication.

Security Mechanisms (X.800)

Model for Network Security

Coarse Outline

• Whirlwind tour of Computer Networks• Computer Hack Reloaded: Anatomy of an Attack– Phase 1: Reconnaissance– Phase 2: Scanning– Phase 3: Gaining Access – Phase 4: Maintaining Access– Phase 5: Covering Tracks and Hiding

• Network Security: Mechanisms & Services• Special Topics

Some Network Humor

http://www.amazon.com/Story-About-Ping-Marjorie-Flack/product-reviews/0140502416

Some Network Humor$ ping google.comPING google.com (66.102.7.104): 56 data bytes64 bytes from 66.102.7.104: icmp_seq=0 ttl=53 time=55.990 ms64 bytes from 66.102.7.104: icmp_seq=1 ttl=53 time=44.317 ms64 bytes from 66.102.7.104: icmp_seq=2 ttl=53 time=45.687 ms64 bytes from 66.102.7.104: icmp_seq=3 ttl=53 time=44.993 ms64 bytes from 66.102.7.104: icmp_seq=4 ttl=53 time=45.481 ms^C--- google.com ping statistics ---5 packets transmitted, 5 packets received, 0% packet lossround-trip min/avg/max/stddev = 44.317/47.294/55.990/4.374 ms$ ping amazon.comPING amazon.com (72.21.214.128): 56 data bytes^C--- amazon.com ping statistics ---10 packets transmitted, 0 packets received, 100% packet loss$