1. NETWORK
SECURITY
Cryptography
By:
Abdulmalik Kohaji

2. OUTLINE Network Security - Introduction - Networks - Network Security
- Firewalls
- Cryptography
- Conclusion

3. Introduction Network Security Information Growth Networks Growth
Network Security Growth

4. Networks
General Concepts

5. What is Network? Network Security: Networks Hardware and Devices
Software and Systems
Mediums
Data

6. Communication Media Network Security: Networks Wired Twisted Pair
Coaxial Cable
ITU-T G.hn
Optical Fiber
Wireless
Microwaves
Radio Waves
Spread Spectrum
Infrared

7. Networks Security

8. Overview Network Security: Network Security Purpose Responsibility
Industry
Hardware & Software
Development
Information

9. Information Security Network Security: Network Security
Why do people want to secure networks?
Information means power

10. Rules of Security Network Security: Network Security
- Integrity: all of the information stored is always correct and protected against corruption as well as willful alterations.
- Confidentiality: the ability to share information on the network with intended people only.
- Availability of information

11. Threats Network Security: Network Security Type Description Example
DoS (Denial-of-Service)
The nastiest, and most difficult to address. Easy to launch, difficult to track.
Send more requests to the machine than it can handle.
Unauthorized Access
access some restricted resources
Access a website database without permission

12. Sources of Threats Network Security: Network Security Internal
Systematic
Users
External

13. Lessons Learned Network Security: Network Security Backups
Don't put all the data on one place
Don’t put the restricted data on the network if not needed
Avoid systems with single points of failure
Always update the security system and policy
Stay current with relevant operating system patches
Watch for relevant security advisories

14. Firewalls

15. Definition Network Security: Firewalls Control income and outcome
Checkpoint
Internetworking
Internal Network Assumption

17. Terms Network Security: Firewalls Router Connecting networks together
Manage the traffic
Access Control List
Lists employed to limit the sorts of packets allowed to come in and go out
Demilitarized Zone

18. Types Network Security: Firewalls Application Gateway
Run App Layer as Proxy Server
The most secure but slowest
Packet Filtering
ACL turned on in the router
Less overhead
Hybrid Systems
High Security of AG
Speed and Flexibility of PF

19. Cryptography

20. What ? Network Security: Cryptography Original Word When it was used?
How it was used?
Why it is used for networks now?

21. Terms Network Security: Cryptography Cryptology Encoding Decoding
Encryption
Key
Code-Book
Cryptanalysis
Ciphertext
Plaintext

22. Security Functions Network Security: Cryptography
Authentication: The process of proving one's identity
Privacy/confidentiality: Ensuring that the message is available only to the intended receiver.
Integrity: Assuring the receiver has not been altered in any way from the original message.
Non-repudiation: an approval that the message is really sent by the sender

23. Differences Network Security: Cryptography
WHAT IS THE DIFFERENCE BETWEEN NETWORK SECURITY AND CRYPTOGRAPHY?
Network Security
Firewalls
Auditing
Intrusion Detection Systems (IDS)
Encrypting Messages & Authentication
Cryptography

24. Algorithms Network Security: Cryptography
- Secret Key Cryptography (SKC): Uses a single key for both encryption and decryption
Public Key Cryptography (PKC): Uses one key for encryption and another for decryption
Hash Functions: Uses a mathematical transformation to irreversibly "encrypt" information

26. SKC Network Security: Cryptography
A single key is used for both encryption and decryption
The key must be known to the sender and the receiver
The biggest difficulty is the distribution of the key

28. PKC Network Security: Cryptography Two parties Secure communication
Non-secure communications channel
Without having to share a secret key
The sender’s key is the public key
The receiver key is the private key.

30. Hash Function Network Security: Cryptography One-way encryption
Use no key
Generate a digital fingerprint of a plaintext
Used to encrypt passwords

31. Extensions Network Security: Cryptography
Fuzzy hashes are an area of intense research and represent hash values that represent two inputs that are similar. Fuzzy hashes are used to detect documents, images, or other files that are close to each other with respect to content

33. Why Three ! Network Security: Cryptography Hash Function Integrity SKC
Privacy & Confidentially
PKC
Non-repudiation
User authentication

34. Conclusion

35. Conclusion Network Security: Conclusion Networks Information Internet
Tools & Techniques
Cryptography

36. Thank you
for Listening