Lecture 21: Internet Security Intro to IT COSC1078 Introduction to Information Technology Lecture 21 Internet Security James Harland

Lecture 20: InternetIntro to IT Introduction to IT 1 Introduction 2 Images 3 Audio 4 Video WebLearnTest 1 5 Binary Representation Assignment 1 6 Data Storage 7 Machine Processing 8 Operating Systems WebLearn Test 2 9 Processes Assignment 2 10 Internet 11 Internet Security WebLearn Test 3 12 Future of ITAssignment 3, Peer and Self Assessment

Lecture 21: Internet SecurityIntro to IT Overview  Questions?  Assignment 3  Peer and Self Assessment  Internet Security  Questions?

Lecture 21: Internet SecurityIntro to IT Assignment 3  Reflect Answer reflection questions from tutorials See last lecture for ideas  Research Write about a particular IT topic of your choice (5- 6 paragraphs) electronic voting, information security, 3D user interfaces, digital music, digital video, electronic commerce, natural language processing, DNA computing, quantum computing, cryptography, malware detection and removal, Moore's Law, green computing, …

Lecture 21: Internet SecuritySE Fundamentals Self and Peer Assessment  How well has each person contributed to the group?  Evaluated over the entire semester  Assessed on process, not product  Work out a grade for each person (CR, DI etc)  Then convert this to a mark out of 20  Submit list of marks to tutor with justifications  Repeat previous step until the tutor is satisfied  See guidelines in Blackboard material

Lecture 19: Internet: ImagesIntro to IT Internet Lisa? Hi Dad! Listen! Lisa? Hi Dad! Listen!

Lecture 21: Internet SecurityIntro to IT Internet Structure Application Transport Network Link Network Link Mordor sucks! 2 dor1 Mor 3 suc4 ks! dor1 Mor 3 suc4 ks! Mordor sucks!

Lecture 21: Internet SecurityIntro to IT Internet Structure 1 Mor 1 6 6

Lecture 21: Internet SecurityIntro to IT Internet addresses  Unique 32-bit identifier (up to 4,294,967,296)  Soon to become 128-bit identifier  Managed by Internet Corporation for Assigned Names and Numbers (ICANN)  ISPs get “blocks” of addresses  32-bit string represented as N 1.N 2.N 3.N 4 where N i is in the range  means

Lecture 21: Internet SecurityIntro to IT Internet addresses  Dotted decimal notation is still not very kind to humans …  -> ??.??.??.??  Translation done by name servers which look up the Domain Name System (DNS)  Domains such as rmit.edu.au can be structured by the domain owner (eg goanna.cs.rmit.edu.au)

Lecture 21: InternetIntro to IT IPv4 vs IPv6  Internet Protocol version 4 (used since 1981)  32-bit addresses  Can handle “only’’ 4,294,967,296 unique addresses  Exhausted in February 2011  IPv6 uses 128-bits addresses  IPv6 can handle “only” 3.4×10 38 addresses  IPv5 didn’t change the IPv4 address space and wasn’t successful for other reasons …

Lecture 21: Internet SecurityIntro to IT Internet Security password patch spam fire wall virus war driving key logger proxy wormphishing Trojan horse

Security vs access  It is always a trade-off (a balance between two competing forces)  More security means less access  More access means less security  Redundancy can be either fatal or vital  Nothing is perfect!

Freedom vs security  `Everything which is not forbidden is allowed’ -- Principle of English Law  `Everything which is not allowed is forbidden’ -- Common security principle  `Anything not mandatory is forbidden’ -- “military policy”  `Anything not forbidden is compulsory’ (??) — T.H. White (The Once and Future King)

Lecture 21: Internet SecurityIntro to IT Passwords  Should be:  Long (8 characters or more)  Not obvious or from a dictionary  Contain capitals, numerals and non- alphanumeric characters …)  Recorded securely somewhere  Transmitted in encrypted form only  Older programs such as FTP, Telnet transmit this in plaintext …

Lecture 21: Internet SecurityIntro to IT Firewalls  Device which limits internet connections  Limit network uses to only approved ones  Prevent malicious software reporting information  Prevent outside attacks  May need to have ports opened to allow applications to work  Only work on applications, not on content

Lecture 21: Internet SecurityIntro to IT Proxy servers  All internet traffic routed via proxy server  Acts as an internet gateway  Once proxy is secure, so is network  Can filter content  Can cache content  Often used with a firewall in a corporate environment

Lecture 21: Internet SecurityIntro to IT Wardriving  Driving around to find a vulnerable wireless signal  Find a wireless connection that doesn’t require a password (so add one to yours if you haven’t!)  Attack systems that use a default admin login name and password (change yours!)  Snoop on transmissions which are not encrypted (encrypt yours!)  Using a MAC address whitelist means only specified devices can connect to your router

Lecture 21: Internet SecurityIntro to IT Viruses,Worms,Trojans  Virus: self-replicating program that attaches itself to files and is spread when they are transferred  Worm: self-replicating program that pro- actively spreads itself  Trojan horse: a program that appears legitimate but is in fact malicious

Lecture 21: Internet SecurityIntro to IT Malware and Spyware  Malicious software:  Hidden mail server  Key logging (to capture passwords)  Enable machine takeover  Direct traffic to particular web sites  Analyse behaviour  Act as a proxy  …

Lecture 21: Internet SecurityIntro to IT Denial of service  Prevent network from working normally  Flood a server with ‘invalid’ inputs  Use a network of compromised machines to generate an overwhelming number of requests (Conficker?)  Such zombie machines can form a botnet, which then attack a particular server

Lecture 21: Internet SecurityIntro to IT Tricking the user  Users are often the weakest link in security  attachments containing trojan horses  ‘Phishing’  Malicious web pages  Malicious documents (macros in spreadsheets)  Account stealing (via key logging)  Scams (‘I have $10 million to import’, ‘You have just won the lottery’, …)

Lecture 21: Internet SecurityIntro to IT Protecting your system  Keep up to date with patches (Windows update, Software update)  Use a firewall  Use anti-virus software and keep it up to date  Use anti-spyware tools  Filter for spam and suspicious messages  Be aware of ‘fake alerts’

Lecture 21: Internet SecurityIntro to IT Conclusion  Work on Assignment 3  Check whether your security defenses are up to date