Lecture 25 – Internet & Security

1. Lecture 25 – Internet & Security Information Systems Today Jessup & Valacich, Ch.4 (P.114)

2. How the Internet Works – Web Addresses & Domains • Domain • Identifies the Website (host) • Comes in many suffixes such as: • .edu (educational institutions) • .org (organizations; non-profit) • .mil (military) • .net (network organizations) • Example: microsoft.com • IP Address • Each domain is associated with one or more IP addresses • Format: a 32-bit address written as 4 numbers (from 0-255) separated by periods • Example: 1.160.10.240 • (URL) Uniform Resource Locator • Identifies particular Web pages within a domain • Example: http://www.microsoft.com/security/default.mspx

3. How the Internet Works – Managing the Internet • Domain Name System (DNS) • Maintained by the Internet Registry • Used to associate hosts or domains with IP addresses • Root DNS database is replicated across the Internet • InterNic Registration Service • Assigns Internet Domains and IP addresses • Internet Corp. for Assigned Names and Number (ICANN) has responsibility for managing IP Addresses, domain names, and root server system management

4. World Wide Web • Hypertext • A Web page stored on a Web server • Contains information and links to other related information (hyperlinks) • HTML (Hypertext Markup Language) • A standard method used to specify the format of Web pages • Uses codes/tags which stipulate how the content should appear to the user • Web Browser • A software program used to locate and display Web pages • Includes text, graphics, and multimedia content

5. World Wide Web • HTTP (Hypertext Transfer Protocol) • A protocol used to process user requests for displaying Web pages from a Web server • Web Servers • A special computer that is specifically designed to store and “serve up” Web pages • This machine contains special hardware and software to perform its many specialized functions

6. How the Internet Works – Packet Switching • Packet Switching • Allows millions of users to send large and small chucksof data across the Internet concurrently • Based on the concept of turn taking, packets from each user are alternated in the shared network (below) • Networks connected to the Internet use this concept

7. How the Internet Works – TCP/IP & Routers • TCP – Transmission Control Protocol • Breaks information into small chucks called data packets • Manages the transfer of the packets from computer to computer • Reassembles data packets into a message at the destination • IP – Internet Protocol • Controls how data packets are formed • Addresses each packet with the source and destination address • A data packet conforming to the IP spec is called an IP datagram • Routers • Connect one network to another • Identify each device on a network as unique using IP protocol • Serve as the “Traffic Cop” directing packets to their destination

8. Example: Sending a message from Computer A to D (Router) Reads IP Address of packet, routes message to Network 2 and Computer D (Computer A) TCP - Breaks message into data packets IP - Adds address of destination Computer D (Computer D) TCP - Checks for missing packets, reassembles message, discards duplicate packets

9. Information System Security IS Security Precautions taken to keep all aspects of information systems safe from unauthorized use access • Managerial Methods • Several techniques are commonly used to manage information systems security: • Risk Assessment • Controlling Access • Organizational Policies and Procedures • Backups and Recovery Security Resources A number of organizations exist to raise awareness, research, develop standards, and advise on solutions for Internet security (e.g. CERT/CC, CSD, CSIT)

10. Information System Security – Managerial Techniques • Assessing Risk • Security Audit identifies all aspects of information systems and business processes that use them • Risk Analysis assesses the value of assets being protected • Alternatives based on Risk Analysis: • Risk Reduction – implementing active counter measures to protect systems (e.g. firewalls) • Risk Acceptance – implementing no counter measures • Risk Transference – transferring risk…buying insurance • Controlling Access • Keeping information safe by only allowing access to those that require it to do their jobs • Authentication – verifying identity before granting access (e.g. passwords) • Access Control – Granting access to only those system areas where the user is authorized (e.g. accounting)

11. Information System Security – Managerial Techniques • Organizational Policies and Procedures • Acceptable Use Policies – formally document how systems should be used, for what, and penalties for non-compliance • Backups and Disaster Recovery • Backups – taking periodic snapshots of critical systems data and storing in a safe place or system (e.g. backup tape) • Disaster Recovery Plans – spell out detailed procedures to be used by the organization to restore access to critical business systems (e.g. viruses or fire) • Disaster Recovery – executing Disaster Recovery procedures using backups to restore the system to the last backup if it was totally lost

12. State of IS Security - Security Threats & Technologies • Security Threats • Today we hear about many security breaches that affect organizations and individuals. Some recently in the news: • Identity Theft – gaining access to some ones personal information allowing them to imitate you (stolen laptop) • Denial of Service – attacks on websites using zombie computers that overwhelm the site and shuts it down • Others: Spyware, Spam, Wireless Access, Viruses • Security Technologies • Companies and research organizations continue to develop and refine technologies to prevent security breaches. Some Include: • Firewalls • Biometrics • VPN and Encryption

13. IS Security: Technology Firewalls A system of software, hardware or both designed to detect intrusion and prevent unauthorized access to or from a private network • Firewall Techniques • Packet Filter – examine each packet entering and leaving network and accept/reject based on rules • Application Level Control – Performs certain security measures based on a specific application (e.g. file transfer) • Keyword based filtering • Destination (URL) based filtering • Certain URLs not permitted (OR) • Certain URLs only are permitted

14. Security Threat: Spyware, Spam, and Cookies • Spyware • Any software that covertly gathers information about a user through an Internet connection without the users knowledge • Problems: uses memory resources, uses bandwidth, and can cause system instability • Prevention: Firewalls and Spyware software • Spam • Electronic junk mail or junk newsgroup postings usually for purpose of advertising for some product and/or service • Problems: nuisance, wastes time deleting, uses storage • Prevention: Spam Blocker software • Cookies • A message passed to a browser from a Web server. Used by legitimate programs to store state and user information • Problems: can be used to track user activities • Prevention: browser settings, firewall

15. Security Technology: Biometrics • Biometrics • A sophisticated authentication technique used to restrict access to systems, data and/or facilities • Uses biological characteristics to identify individuals such as fingerprints, retinal patterns in the eye, etc. that are not easily counterfeited • Has great promise in providing high security

16. Security Threat: Access to Wireless • Unauthorized Access to Wireless Networks • With the prevalence in use of wireless networks this threat is increasing • Problems - Drive-by hacking an attacker accesses the network, intercepts data from it, and can use network services and/or sends attack instructions without entering the building • Prevention - Encryption between network and user devices

17. Security Technology: VPN and Encryption • VPN (Virtual Private Network) • Called a secure tunnel • Dynamically generated network connection to connect users or nodes • This approach uses both authentication and encryption • Used extensively for remote access by employees • Encryption • The process of encoding messages before they enter the network or airwaves, and then decoding at the receiving end • Public Key - known and used to scramble messages (SSL) • Private Key - not known and used by receiver to descramble • Certificate Authority – a third party that issues keys

18. How Encryption Works

19. Security Threat: Viruses Viruses Programs that can attack a computer and/or a network and delete information, disable software, use up all system resources, etc. Prevention Steps: AntiVirus software: install this software which is designed to block all known viruses and offers automatic or manual updates to virus patterns to block future viruses No Disk Sharing – Viruses can be transferred to clean computers by inserting disks containing infected files Delete Suspicious Email Messages – Do not open suspicious e-mail messages…Delete Only! Report Viruses – If you get a virus, report it to you network administrator immediately!