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Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
Security/Networking Encryption Encoding information ...
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Security/Networking Encryption Encoding information ...

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Transcript

  • 1. Security/Networking
  • 2. Encryption
    • Encoding information – cryptography
      • Dan Brown’s “DaVinci Code” and “Digital Fortress”
    • The Caesar Cipher
      • Julius Caesar encoded messages by replacing each letter with 3 rd letter after in alphabet (a=d, b=e, z=c, etc.)
      • Improve: use cipher alphabet BUT use different shifts for subsequent letters
        • 1 st letter = shift by 3 letters
        • 2 nd letter = shift by 1 letter
        • 3 rd letter = shift by 4 letters
        • Pi = 3.1415926
      • What would ‘Hello’ be?
  • 3. Encryption
    • Public-key systems
      • Used with modern computer systems
      • Complex mathematical formulas
      • Person wishing to receive messages will publish public key (often 128 bits – larger the key – longer to break)
        • Example:1000 years
      • Important for e-commerce (secure sites)
      • PGP – Pretty Good Privacy – protects data in storage, too
          • Public key is for encryption
          • Private key is for decryption
      • Debate over public key encryption
        • Terrorists use encryption
        • Yet, needed for e-commerce growth
    • TLS/SSL – Transport Layer Security/Secure Sockets Layer
      • Web browsers
      • Protects data in transit over a network
  • 4. Security for Wireless Computer?
    • Wireless networks
      • Passwords control what computers and users access network
        • Encryption and Authentication
        • Encryption:
          • WEP (Wired Equivalency Privacy)
            • Protects against casual snooping
            • No longer recommended – crack in minutes
          • WPA (Wi-Fi Protected Access)
            • Works with all wireless network adapters but not all older routers or access points
          • WPA2 (Wi-Fi Protected Access)
            • More Secure than WPA
            • Will not work with some older network adapters
  • 5. Wireless Security
    • Prevents ‘Piggybacking’
        • Tapping into someone else’s wireless Internet connection without proper authorization
          • Illegal in some states
        • NY Times Article 2006
  • 6. Passwords – Problems
    • Easily guessed (40-50%)
    • Share passwords
    • Post password next to computer
    • Passwords too short
  • 7. Password Solutions (PC Mag Feb. 2008)
    • Use ‘strong’ passwords
      • Mix numbers and letters; mix case
      • The longer the better (6-8 chars or longer)
        • Brute Force – trying every combination until password is determined
      • Pet, kids and spouse names make bad passwords
      • Be inconsistent – use different passwords for different sites (I know…hard to do!)
      • Change passwords often
  • 8. Security Solutions - Revised
    • No such thing as 100% security :
      • Make sure Operating System is up-to-date (automatic update/service packs)
      • Use anti-malware programs/Security Suites (update)
      • Use a bidirectional firewall
      • Use additional anti-spyware scanners (Spybot S&D, Adaware, Windows Defender)
      • Secure wireless network (WEP/WPA/WPA2)
      • Use unique (strong) passwords
      • Consider using different browser – Internet Explorer is a popular target (Opera, Firefox)
      • Use encryption (E-mail, IM - example ‘PGP Desktop’)
      • Backup important files (ex. storms, hardware failure)
      • Be mindful of “social engineering” issues (Phishing, Facebook)
      • Turn computer OFF when not in use
  • 9. Networking
  • 10. What are File Servers?
    • Network – a group of two or more computers connected together for exchanging data/information and sharing resources
    • File Server – centralized computer used for storing (and sharing) programs and files.
      • Examples: Database server, Web server, mail server, general file servers
    • Client-server
      • Client – computer that ‘receives’ data
      • Server – computer that provides services to a client
  • 11. Message
    • A communication that is transferred from one node on a network to another.
      • E-mail
      • Web Pages
      • FTP (File Transfer Protocol)
  • 12. Networks
    • Bandwidth
      • Amount of data that can be transmitted across transmission medium in a certain amount of time
    • Packet
      • Data (Web pages, e-mail messages, etc.) is transmitted in bundles called packets
        • Header
          • Sender’s IP address
          • Receiver’s IP address
          • Protocol
          • Packet Number
        • Data
  • 13. TCP/IP- Tells which application should be used for a network message
    • Transmission Control Protocol/Internet Protocol 
    • Used with Ethernet networks
    • IP header – includes information about which application should be used for each message
    • IP – specifies a way of sending packet information from source to destination
    • Port Address (16-bit number)
    • Packets can travel separately to your computer.
    • ICANN maintains list of well-known ports (0-1023)
      • Registered ports 1024-49151
  • 14. Port Addresses
    • Port Address (16-bit number) 
      • 21 – message contains FTP commands
      • 20 – message contains file related to FTP command
      • 23 – Telnet
      • 25 – E-mail
      • 80 – HTTP (access to World Wide Web)
    • Also used by firewall (screen port numbers)
  • 15. Firewall – Guard Against External Threats
    • Acts as a barrier between your system and outside world
    • Ports provide application-routing information for every message
      • 21 (FTP)
      • 25 (E-mail)
      • 80 (HTTP)
      • 12345 (NetBus – Trojan) *Block*
    • Firewall screens ports
      • Norton Internet Security
      • McAfee Internet Security
      • Windows XP (blocks only incoming traffic)
  • 16. Wireless Technology
  • 17. Wireless Technology
    • Access Point
      • Computer connected to the Internet (acts as intermediary)
      • Name is SSID (Example: RoyalAir) (to broadcast or not to broadcast?)
        • Microsoft's Answer
      • Usually user able to configure security features 
    • Wireless Router – attaches to access point computer
    • Beacon
      • Repeating of identifying information by access point
      • Example: on a 2.4 GHz radio frequency band
    • Association – Portable wishes to make connection
    • Radio waves or infrared signals used to communicate with access point
      • As portable computers move, interact with new access point
      • If no computers have direct access to the Internet, portable computers still can interact with each other, but not with the Internet

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