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IS 302: Information Security and Trust Week 1: Introduction to IST, Security, and Networks 2013

Course material

– My web site – eLearn © Yingjiu Li 2005 2

Basic Modules

Background (1 week) Applied Crypto (4 wks) Network Security (4 wks) Access Control (1 wk) Project Presentations (2 wk) 3

Information Security & Trust

Security in Computing: International Edition

Author: Charles P. Pfleeger Shari Lawrence Pfleeger Edition: 4 th edition ISBN: 9780136012962

Available in your school bookshop!

• • • • •

Grading

– –

Individual Assignment (10%)

Assignment 1(week 3) Assignment 2 (week 10) – – – –

Group Project (25%)

Presentation (15%) + report (10%) Outline due in week 9 (Friday) Presentation in weeks 12 and 13 (15%) Final report due in week 14 (10%)

Midterm Quiz (15%; week 7)

–

Final Exam (40%; week 15) SMU final exam policy : Students are not allowed to reschedule their examination or request for special arrangements of the examination from instructors.

Attendance and Participation (10%)

Policies

• • • •

Honor code

– No plagiarism or cheating (SMU Code of Student Conduct)

Due time

(assignments, project, quiz, exam) – Strictly enforced – Points (~10%) may be deducted for late turn-in

Excuses

– No excuse for project, midterm quiz, and final exam – Must be approved before hand

Class arrangement

Introduction to Networks

Host A App A App B Network Architecture Host B App A App B Subnet 1 Router Internet Robert Deng/SMU Subnet 2 Link Level 8

The Internet Protocol Layers Apps TCP/UDP IP D-Link Physical Host A Internet Host B Apps TCP/UDP IP D-Link Physical IP datagram/packet Src IP Adr; Des IP Adr Src Port#; Des Port# Payload IP header TCP/UDP header Robert Deng/SMU 9

Terminology

• IP Address : An Internet identifier for each network interface ( Address of a building ) – Example: 202.161.41.246

• Port Number : An identifier for an application in a host ( Room number in a building ) • Hostname : An Internet name of a host ( Name of a building ) – Example: www.smu.edu.sg

• Domain name : An identifier of a domain, which is a network of associated hosts – Example: smu.edu.sg

Router

• The postman in the Internet – stores and forwards IP packets • On arrival of an IP packet, it makes a routing decision based on the packet’s destination IP address.

• Routing decision: to choose the next router to forward the packet, based on a routing table 11

Domain Name System (DNS)

A service translating “Names” to “IP addresses” local DNS server

ns01.staff.smu.edu.sg

authoritative DNS server

dns.google.com

www.google.com

your laptop 12

Transport services and protocols

Host A • Provide

logical communication

between

app processes

on different hosts running application TCP/UDP network data link physical network data link physical • Transport protocols run in end network data link physical systems network data link physical – sending side: breaks app network data link physical messages into segments , passes to network network data link physical – receiving side: reassembles segments into messages, passes to applications application TCP/UDP network data link physical • More than one transport protocol available to apps Host B – Internet: TCP and UDP 13

Internet Transport Layer Protocols

• Reliable, in-order delivery (TCP) – connection setup • Unreliable, unordered delivery: UDP • Services not available: – delay guarantees – bandwidth guarantees application TCP/UDP network data link physical network data link physical network data link physical network data link physical network data link physical network data link physical application TCP/UDP network data link physical 14

Port Number

• Port : identity of an application • IP address + port number can uniquely identify an application running in a host in the Internet.

• Well-known Port numbers: – Web: TCP port 80 – Email Transportation: TCP port 25 – Email Retrieval: TCP port 110 – DNS: UDP port 53 • Both the client and the server need to specify their port numbers for data transmission.

HTTP overview

HTTP: hypertext transfer protocol • Web’s application layer protocol • client/server model –

client:

browser that requests, receives, “displays” Web objects –

server:

Web server sends objects in response to requests • HTTP 1.0: RFC 1945 • HTTP 1.1: RFC 2068 HTTP has nothing to do with how a web page is interpreted PC running Explorer Mac running Navigator Server running Apache Web server Server: • always on • fixed address 17

Electronic Mail

Three major components: • User agents • Mail servers • Simple mail transfer protocol: SMTP User Agent • “mail reader” • Composing, editing, reading mail messages • e. g., Eudora, Outlook, elm, Netscape Messenger • Outgoing, incoming messages stored on server 18 mail server user agent SMTP SMTP outgoing message queue user mailbox user agent mail server user agent mail server SMTP user agent user agent user agent

Mathematic Notation

• x mod n, where x and n are natural numbers – means the remainder of x divided by n – e.g. 111 mod 879 equals to 111, – e.g. 8913 mod 2 equals to 1 • x=y (mod n) – means that x and y are congruent to n – in other words, x and y have the same remainder when divided by n .

– e.g. 8913=8927 (mod 2) • x -1 mod n – means the inverse of x with respect to n or mod n , – Namely, x  x -1 =1 (mod n) – this is NOT 1/x !!!!!

– e.g. 3 -1 mod 5 = 2, because 2*3=6 =1 (mod 5) -1 Good news: You are not required to compute the modular inverse.

Motivation

• To fight against cybercrime • I can attack U © Yingjiu Li 2005 21

Achieve

CIA

C ONFIDENTIALITY I NTEGRITY A VAILABILITY

Objectives

• C onfidentiality (secrecy, privacy) – Information is not exposed to unauthorized parties.

• I ntegrity – Information is not modified by unauthorized parties.

• A vailability – Information can be accessed by authorized parties at proper time.

CIA-U

U SAGE C ONFIDENTIALITY

I NTEGRITY

R. Sandhu

A VAILABILITY

4 Objective

• Usage – Information is not misused by authorized parties © Yingjiu Li 2005 25

Mitigate

TVA • T hreat – Something bad could happen • V ulnerability – Weakness in an information system could be exploited • A ttack – Some vulnerabilities are actually exploited by some adversary, which may result in security incidents © Yingjiu Li 2005 26

Bot-network operators Hackers Insiders Nations Phishers Spammers

Sources of Cybersecurity Threats (United States Government Accountability Office GAO-10-606)

Criminal groups Spyware/malware authors Terrorists

Use a network, or bot-net, of compromised, remotely controlled systems to coordinate attacks and to distribute phishing schemes, spam, and malware attacks. The services of these networks are sometimes made available on underground markets.

Seek to attack systems for monetary gain (e.g., identity theft and online fraud) or conduct industrial espionage. They hire or develop hacker talent. Break into networks for the thrill of the challenge, bragging rights in the hacker community, revenge, stalking others, and monetary gain, among other reasons Includes disgruntled employees, contractors hired by the organization, as well as employees who accidentally introduce malware into systems. Nations use cyber tools as part of their information-gathering and espionage activities. In addition, several nations are aggressively working to develop information warfare doctrine, programs, and capabilities. Individuals, or small groups, execute phishing schemes in an attempt to steal identities or information for monetary gain Individuals or organizations distribute unsolicited e-mail with hidden or false information in order to sell products, conduct phishing schemes, distribute spyware/malware, or attack organizations (i.e., denial of service). Individuals or organizations with malicious intent carry out attacks against users by producing and distributing spyware and malware. Seek to destroy, incapacitate, or exploit critical infrastructures in order to threaten national security, cause mass casualties, weaken a nation’s economy, and damage public morale and confidence.

Attacks

Difficult to detect but relatively easy to counteract Difficult to prevent absolutely but relatively easy to detect; the goal is to detect them and to recover from any disruption Robert Deng/SMU 28

Hardware and Software Grow

• Moore’s law – (Hardware) processing power doubles every 18 months • Gates’ law – Software grows to use all processing power • Multics 1970: ~55k lines of code • Windows 2000: ~55M lines of code © Yingjiu Li 2005 30

More Vulnerabilities

High Network Value

• Metcalfe’s law – Value of a network is proportional to the square of number of users – Internet 1970: ~10K users – Internet 2005: ~1B users © Yingjiu Li 2005 32

High Security Risk

• Evan’s Law – Security risk is the product of the number of vulnerabilities and the value of network © Yingjiu Li 2005 33

Even Worse: Defense is So Hard

Principle of Easiest Penetration An intruder can exploit any vulnerability to launc an attack – An intruder only needs to find one vulnerability – Defender needs to control all possible vulnerabilities • Features of cyber attacks – Action at a distance (difficult to trace & prosecute) – Propagation of attacking techniques (hacker groups, bulletin boards; only the 1 st needs skill, the rest just use the s/w) 34

How to Achieve Security Objectives

• Policy – What to protect • Mechanism – How to protect • Assurance – How well is protection Security Assurance Mechanism Policy © Yingjiu Li 2005 36

Can We Hide?

• Security by Obscurity – A system would be secure if we hide its insides?

• • It won’t work well – Vendor independent standards – Open source – Widespread knowledge and expertise

Kerckhoffs Principle

(1883): Only the key should be kept secret, while the algorithm itself should be publicly known.

Can We Instruct?

• Security by legislation – A system will be secure if we instruct users to behave in a secure, ethical and lawful manner – Example: Corporate Acceptable Use Policy • It is not adequate – Users’ cooperation is important; however, it should not be our main focus for achieving security – Attackers (outsider and insider attackers) will not follow instructions 38

Tradeoffs

Discussion

•

Good security and bad security

Project

•

Project (25%)

– Investigation on a security/privacy related topic (each team chooses a different topic) – Project presentation (15%) • Presentation organization (5%); • Technical description(5%) • Q&A (5%) • Timing: 20~25 min presentation + 5~10 min Q&A – Final report (10%) • Breadth (5%) • Depth (5%) © Yingjiu Li 2005 41

Project – Due Time

• Project outline is due in

week 9

. • Project presentation is scheduled in

weeks 12 and 13

. • Project report is due in

week 14

Topics

1) Web browser security 2) SSL security issues and solutions 3) Privacy leakage and control in online social networks 4) Authentication and anonymity in location based services 5) Differential privacy 6) Android permission models and enforcement 7) iOS malware and detection 8) Android malware and detection 9) Timing based attestation 10) Password strength measurements © Yingjiu Li 2005 43

Must do before next class

• Download and install Cryptool – http://www.cryptool.org/en/ct1-download-en • • CrypTool 1.4.30 - English version CrypTool 1.4.31 Beta 05 - English version • We will use this tool frequently in class © Yingjiu Li 2005 44