Internet Security Essentials: Threats, Measures, and Encryption

1. Chapter 10 Security On The Internet

2. Agenda • Security • Cryptography • Privacy on Internet • Virus & Worm • Client-based Security • Server-based Security

3. Security • Security and trust requirements • Threats on the Internet • Sources of the threats • Security policy

4. Security and Trust Requirements • Confidentiality • Integrity • Availability • Legitimate use • Non-repudiation

5. Threats on the Internet • Loss of data integrity • Loss of data privacy • Loss of service • Loss of control

6. Sources of the Threats • Hackers • Cyber terrorists • Employee error • Missing procedures • Wrongly configured software

7. Hackers • Monitoring the communication • Private information & password • Steal hardware & software • Smart card or database • Intercept the output of a monitor screen • Overloading the service • Trojan horses – virus • Masquerading (IP address spoofing) • Dustbin

8. Hackers • Bribe employee • Information of internal network or internal DNS structure • Social Engineering • Exploiting habits of employee • Pretending an employee • Organization chart • Phone book • Information gathering and social pressure

9. Hackers • Counter measurements • Firewall • Two-factor authentication (know and have) • Audit log file • Digital certificate (user or server) • Message encryption

10. Cyber Terrorists • Definition • Use computer resources to intimidate others • Methods • Virus attack • Alteration of information • Cutting off Communication • Killing from a Distance • Spreading misinformation

11. Cyber Terrorists • Counter measurements • Commission of Critical Infrastructure Protection • Disconnect mission critical systems from public network • Firewall to monitor communication • The eternity service concept (duplication and encryption)

12. Security Policy • List of resources needed to be protected • Catalogue the threats for every resource • A risk analysis (cost and benefit) • Centralized authorization • Physical access control (policy & procedure) • Logical access control (policy & procedure) • Test, review and update

13. Agenda • Security • Cryptography • Privacy on Internet • Virus & Worm • Client-based Security • Server-based Security

14. Cryptography • Secret key • Public key • Steganography • Applications

15. Secret Key • Symmetric cryptography • A single key for encryption and decryption • Use different medium for key and message • Fast encryption and decryption • Types • Stream ciphers: bit level • Block ciphers: pre-defined length into a block

16. Public Key • Asymmetric key cryptography • SRA algorithm: two distinct keys (private and public) for every users • Public key decrypt messages encrypted with private key • Long time to encrypt and decrypt message • RSA to encrypt the symmetric key which encrypted the message

17. Public Key • Usages • Communication between web server and web browsers for create session key • E-mail uses different public key for different recipients

18. Steganogrphy • Hide information in the ordinary noise and digital systems of sounds and images • Low quality of free software • Higher quality for commercial software • Law requirements for encryption and decryption

19. Applications • Enforce privacy • Storing the hash value of password • Encrypting e-mail • Pretty Good Privacy (PGP): unbreakable • Secure Multipurpose Internet Mail Extensions (S/MIME): ease to set up with less security • Separate the use of strong symmetric encryption algorithms and e-mail software • WinZip: for e-mail read by multiple person and password over the phone

20. Applications • Digital Signatures • Digital hash or digital code for each message • Encrypt the digital code with private key • Decrypt the digital code with public key • Digital time stamp (time and date) encrypted with private key by third party

21. Agenda • Security • Cryptography • Privacy on Internet • Virus & Worm • Client-based Security • Server-based Security

22. Privacy on Internet • Footprints on the Net • TRUSTe • The platform for privacy preferences • Anonymity

23. Footprints on the Net • Request a web site • The name of the browser • The operating systems • Preferred language • The last visited web site • IP address and domain name • The client location • The screen resolution and number of colors

24. Footprints on the Net • Cookies • The password to open a site • A user name • An e-mail address • Purchasing information

25. TRUSTe • An independent, non-profit privacy organization issues online seal called “trustmark” • To certify an online business is trustworthy, safe and allow checking the privacy practice by a third- party • Hard to understanding the privacy information by end user

26. The Platform for Privacy preferences • Platform for Privacy Preference Project (P3P) by W3C • Define a way for web site to inform the users of privacy practice before the first page

27. Anonymity • Anonymous remailers to replace the header of original e-mail with remailer’s • Anonymizer

28. Agenda • Security • Cryptography • Privacy on Internet • Virus & Worm • Client-based Security • Server-based Security

29. Virus • Types of viruses • Virus damage • Virus strategy

30. Types of viruses • Boot sector virus • Executable virus • Macro virus • Hoax viruses and chain letter

31. Virus Damage • Annoying • Harmless • Harmful • Destructive

32. Virus Strategy • Firewall • Anti-virus program • Scanner • Shield • Cleaner • Backup strategy • Education of employee with a frequently asked questions (FAQ) page

33. Agenda • Security • Cryptography • Privacy on Internet • Virus & Worm • Client-based Security • Server-based Security

34. Client-based Security • Digital certificates • Smart card • Biometric identification

35. Digital Certificates • Personal information (name and address) file encrypted and password-protected with public key and certification authority (name and validity period) • Types • Browser and server: SSL encryption • Customer and merchant: SET encryption • Two e-mail partners: S/MIME

36. Smart Cards • Uses electronically erasable programmable red only memory (EEPROM) • Types • Contact cards • Contactless cards • Combi cards • Information Access • Read only • Add only • Modify or delete • Execution only

37. Biometric Identification • Physical characteristics or behavioral traits • Issues • Acceptance • Accuracy • Cost • Privacy

38. Agenda • Security • Cryptography • Privacy on Internet • Virus & Worm • Client-based Security • Server-based Security

39. Server-based Security • Isolation of web server • Application Proxies • Multi-layered firewall • A trusted operating systems (TOS) • Backup • Least privilege • Balance of power • A good audit system

40. Trusted Operating Systems • Types • Virtual Vault by Hewlett Packard • Trusted Solaris by Sun • Features • Firewall • Intranet • Internet • Distributed system: data and program • Least privilege • Peak usage management • Multi level security • Audit system

41. Audit System • Adaptable • Automated • Configurable • Dynamic • Flexible • Manageable • System-wide

42. Points to Remeber • Security • Cryptography • Privacy on Internet • Virus & Worm • Client-based Security • Server-based Security