1. SSL/TLS after DigiNotar and BEAST
Course: Cyberdefence Seminar
Lecturer: Ahto Buldas
Author: Mikheil Basilaia a106936

2. The Plan SSL/TLS overview BEAST hack DigiNotar hack
Future of communication security in internet

3. What is SSL? Stands for Secure Socket Layer
Cryptographic protocol securing connections
Predecessor of Transport Layer Security (TLS)
Foundation for communication security in internet

4. Functions SSL/TLS uses: Certificates for authentication
Digital signatures and message digests for integrity
Encryption for privacy/confidentiality

5. Versions SSL 1.0 (never released for wide usage) SSL 2.0 (1995)
TLS 1.0 / SSL 3.1 (1999)
TLS 1.1 / SSL 3.2 (2006)
TLS 1.2 / SSL 3.3 (2008)

6. Usage
By Qualys

7. BEAST Stands for Browser Exploit Against SSL/TLS
Attacks SSL 3.0 and TLS 1.0
Breaches confidentiality (while other attacks aim authentication)
Published in September, 2011 by Duong and Rizzo
Exampled on PayPal payment

8. BEAST – Technical Details
Attacks active SSL/TLS connections
Decrypts cookies
Plaintext recovery attack
Exploits vulnerability connected to cipher block chaining (CBC)

9. BEAST – Requirements/Limitations
Needs JavaScript code running
Needs control over victim’s network
Needs to overcome same-origin policy
Some ciphers (RC4) does not use CBC (AES and DES use)

10. BEAST – What can we do? Update IE Use Chrome (uses RC4)
Disable JavaScript in Firefox

11. DigiNotar Hack Dutch Certification Authority
Over 500 certificates lost (including certificates for Google, Microsoft, Skype, Dutch government, CIA, Mossad. . .)
Hacked in July, went public in August, declared bankruptcy in September, 2011

12. DigiNotar – Other Details
DigiNotar system used to issue fake certificates
Farsi-speaking hacker
Failed because technical negligence
The case posed a question of security in internet

13. Usage Iranian Gmail users eavesdropped
Man-in-the-middle-attack (attack on confidentiality)
Needs traffic to be rerouted to other servers – probably government involvement

14. What can we do?
Disable DigiNotar certificates (do it manually or update browsers)
Mac products/Windows XP/Windows Server 2003 may need manual deletion

15. An Example

16. What if. . . Other CAs also fail? VeriSign – too big to fail?
Swedbank/SEB/Nordea use certificates by VeriSign
Security in internet will be undermined

17. Future Implement TLS 1.2/TLS 1.3
Maybe needs bigger failure than DigiNotar
DigiNotar example can be attractive for powerful cyber actors

18. Thank You