1. Internet Security CS457 Seminar Zhao Cheng

2. Security attacks interruption, interception, modification, fabrication
passive attack, active attack

3. Security services Confidentiality Authentication Integrity
Nonrepudiation

4. IPSec services
SA(Security Association): one way relationship, identified by
SPI(Security Parameter Index).
IP Destination Address.
Security Protocol Identifier:
AH(authentication Header)
ESP(Encapsulation Security Payload)

5. Two modes Transport mode: protection for upper layer protocol.
Tunnel mode: protection to entire IP packet.

6. Authentication header
Header definition.
Anti-Replay service
Integrity check value

7. Encapsulating Security Payload
Format.
Encryption and authentication.

8. Key management
Manual: configured by system administrator with its own keys and keys of other systems.
Automated: on demand creation of keys for SAs, ISAKMP(Internet Security Association and Key Management Protocol) by default.

9. Benefit of IPSec Strong and easy security for group behind firewall.
Transparent to applications.
Transparent to end users.
Security for individual users can be provided.

10. TLS(transport layer security)
Object: reliable end to end security over TCP.
Construction: two layers of protocols.

11. SSL Record Protocol
Record Protocol Operation and format.

12. SSL Handshake Protocol
Phases:
Establish Security Capabilities.
Server Authentication and Key Exchange.
Client Authentication and Key Exchange.
Finish.

13. Example on handshake protocol

14. Services of TSL Integrity: by cryptographic checksums.
Confidentiality: by encryption on SSL payloads.
Authentication: by handshake protocol.

15. Summary
Attacks on network security and corresponding security services.
IPSec: Services approaches on IP layer.
TLS: Services approaches on transport layer.