1. 1 DCS 835 – Computer Networking and the Internet Digital Certificate and SSL (rev.06-17-07) Team 1 Rasal Mowla (project leader) Alvaro Restrepo, Carlos Thomas Kevin Gravesande, Scott Weaver

2. 2 Agenda  Digital Certificate  Digital Certificate Example  SSL  SSL Example  Protocol Overview  Why SSL is Secure  SSL Versions  Conclusion

3. 3 What is a Digital Certificate Digital Certificate prove your identity or your right to access information or services online. They bind an identity to a pair of electronic keys that can be used to encrypt and sign digital information. A Digital Certificate is issued by a Certification Authority (CA) and signed with the CA's private key. A Digital Certificate typically contains the: Owner's public key Owner's name Expiration date of the public key Name of the issuer (the CA that issued the Digital Certificate) Serial number of the Digital Certificate

4. 4 Example of Digital Certificate From: Staples.com

5. 5 Digital Certificates What are Digital Certificates used for? Digital Certificates are used in e-mail, e-commerce, groupware and electronic funds transfers, code signing, VPNs, and SSL (security and encryption). Why do I need a Digital Certificate? Digital certificates provide with security and privacy for transacting online transactions. How do I use Digital Certificates? Digital certificates can be used in conjunction with digital signatures to provide authenticity. Furthermore, they provide verification of identity for secure server access.

6. 6 Reference: http://ospkibook.sourceforge.net/docs/OSPKI-2.4.7/OSPKI-html/sample-ca-cert-txt.htm

7. 7 Digital Certificates and SSL What is SSL and what is it used for? Secure Sockets Layer (SSL) protects the data transferred using encryption enabled by a SSL server’s certificate. Browser address directs to a secured domain, SSL handshake authenticates the server and client and establishes an encryption method and a unique session key. Encryption is done by a public key and a private key deciphers it. Why do I need a SSL? Provides a secure medium of communication between a client and server via encryption.

8. 8 SSL (Introduction) Reliable commutation on the Internet SSL Main Goal: –Cryptography security –Reliability –Interoperability –Extensibility –Relative efficiency Chiper Used with SSL

9. 9 Uses of SSL 1.An organization, which wants to supply Internet privacy communication between it and its clients, may use the SSL protocol. 2.Bank-Systems are using this protocol to allow their clients to view their confidential accounts’ data on their own browser and to make their account orders from home. 3.The same idea is applied in academic organizations. Students can view safely personal information on the web, such as course grades. 4.Most electronic commerce (i.e. the sharing of personal details and credit card numbers) through the net is protected under SSL.

10. 10 SSL Example http://www.bankofamerica.com

11. 11 SSL Example

12. 12 SSL (Protocol Overview) SSL is a Layered protocol. The SSL Protocol Stack

13. 13 SSL (Protocol Overview) cont. SSL Handshake protocol –Establishes a secure session –Structure: · Type: SSL handshake message type. · Length: Length (in bytes) of the message. · Content: Parameters additional to the message.

14. 14 SSL (Protocol Overview) cont. SSL Handshake protocol

15. 15 SSL (Protocol Overview) cont. SSL Change Chiper Spec protocol –Used at the last stage of SSL Handshake in order parties to move from their pending state to their current state. –This message has one byte with content of “1” and is encrypted and compressed under the current CipherSpec.

16. 16 SSL (Protocol Overview) cont. SSL Alert protocol –Responsible for error –Two levels of alert fatal alert warning alert · Level: Indicates a fatal or warning alert. · Alert: Indicates the specific alert.

17. 17 SSL (Protocol Overview) cont. SSL Record protocol –Data is encapsulated into an object called record –Record consist of Header – 5 bytes long Data – portion undergoes 4 stages: Fragmentation, Compression (optional), Applying MAC, and Encryption

18. 18 Why use SSL? Preventing Identity Fraud Preventing Garbling Attacks Preventing Replaying Messages Preventing Cut and Paste Attacks Preventing Cipher Suite rollback attacks Preventing Version rollback attacks Preventing Dictionary attacks Traffic attacks Short-block attacks

19. 19 SSL versions SSL v2.0 SSL v3.0 TLS

20. 20 References Digital Certificates Verising, “Digital Certificates” http://www.verisign.com.au/repository/tutorial/digital/intro1.shtmlhttp://www.verisign.com.au/repository/tutorial/digital/intro1.shtml Verising is one the key and innovative Certificate Authority companies on the web. The Open–source PKI Book: A guide to PKIs and Open–source Implementations. Sample CA Certificate in TXT format http://ospkibook.sourceforge.net/docs/OSPKI-2.4.7/OSPKI-html/sample-ca-cert-txt.htm Website provided sample text image of a digital certificate.http://ospkibook.sourceforge.net/docs/OSPKI-2.4.7/OSPKI-html/sample-ca-cert-txt.htm SSL