IGE105

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IGE105 Communication Technology in a Changing
World

• Dr. Ken Cosh
• Week 14

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Previously

• We talked about the Digital Divide
• What is it?
• Projects that attempt to close the divide
• Value of those projects?

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This Week

• Challenges (still) facing Modern ICTs
• Reliability
• Security

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Reliability

• Redundancy is the Key!
• Spare components
• Components running in parallel
• Triple Modular Redundancy
• Identify unreliable components and arrange back
  ups.
• UPS
• Multiple ISPs

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Security

• Data stored digitally transmitted through
  networks Greater security threats.
• After all digital data can be copied more easily

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Security Threats
Tapping Sniffing Message Alteration Theft/Fraud
Hacking Vandalism DoS attacks Theft/Copy
Data Hardware/Software Failure
Unauthorised Access Errors Viruses/Worms Spyware
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Malware (Malicious Software)Viruses / Worms /
Trojans / Spyware

• Virus
• Display message -gt destroying data
• Spread by human action
• i.e. sending infected email, or copying a file
• Worms
• Dont need human action
• Copy themselves across network on their own.
• Destroy data / Disrupt network

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Malware (Malicious Software)Viruses / Worms /
Trojans / Spyware

• Trojan Horses
• Software appears benign, but then does something
  unexpected
• Doesnt replicate (so not a virus), but may
  facilitate viruses
• Spyware
• Program installs itself and then serves up
  advertising
• Keyloggers record all keystrokes including
  passwords / CC numbers etc.
• Some spyware uses up memory / redirect search
  requests / reset browser home page

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Hackers Computer Crime

• Objective to gain unauthorised access
• Steal information
• System damage
• Cybervandalism
• Defacing websites

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Spoofing / Sniffing

• Spoofing
• Masquerade as someone else
• drkencossh_at_gmail.com
• Redirect you to similar webpage
• www.hsbc.net
• Sniffing
• Eavesdropping on data passed through a network
• Legitimately to identify trouble spots / criminal
  activity
• But also to steal information
• V. difficult to detect

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DoS Attacks

• Denial of Service
• DDoS Distributed Denial of Service
• Fake communications / requests submitted
  simultaneously through network to slow it down
  and prevent legitimate usages.

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Identity Theft

• Perhaps by Phishing
• Asking users for confidential data through fake
  emails/websites
• Please update your records
• Or Evil Twins
• I could set up a trustworthy wifi network
  connection in a hotel lobby

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Countering the Threats

• Tight Security Policies
• Access Control
• Authentication
• Password
• Biometrics
• Firewalls
• Anti Virus
• Encryption

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Security Policies

• Access Control Lists (ACL)
• Limit which users can do what (e.g. update
  websites)
• Signed agreements for service
• When allowing users onto a network, normally they
  sign an agreement, regarding terms of use.
• Noticeably none at Payap?
• Policies could include,
• Regular password changes
• Whether personal use of service is permitted
• Antivirus updates
• Can help against, external attacks, intrusion,
  virus / worms

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Encryption

• Encoding the contents of a transmission so it
  cant be decrypted on route.
• Symmetric-key encryption
• Public / Private key encryption
• Helps prevent interception.

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Symmetric Key Encryption

• Both sender and receiver use the same code to
  encrypt and then decrypt a message.
• If I tell you to move each character back two in
  the alphabet, and then send you this message
• Jgnnq Encuu
• Anyone who intercepts the message gets nothing,
  but you are able to decrypt it.
• More interesting patterns can be created to
  increase security.
• Substitution
• Transposition

Key FANCY Messageeatitnihmexnetmgmedt
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Decoding