1. SECURING E-MAIL Presented by: Digvijay Singh Dudi Graduate Student Old Dominion University

2. Table of contents Brief Introduction Securities available for different layers Why we need security at each layer? Desirable security features in e-mail Confidentiality can be provided through Cryptography Session key Sender authentication and message integrity Pretty Good Privacy(PGP)

3. Brief Introduction Electronic mail commonly known as e-mail is a method of exchanging digital messages from one author to one or more recipients. Today's e-mail is based on a store-and-forward model. E-mail predates the inception of the internet. E-mail servers accept, forward, deliver and store messages. Users and the computers are not required to be online simultaneously; they need to connect only briefly, typically to a mail server for as long as it takes to send/receive messages.

4. Securities Available for different Layers At Application Layer: Pretty Good Privacy(PGP) At Transport Layer: SSL Protocol At Network Layer: Ipsec, IEEE 802.11 Wireless LAN Protocol

5. Why we need security at each layer? Two major reasons: Network layer security can encrypt data in the datagrams and authenticate source IP address, but cannot provide user level security. More easy to deploy new Internet services, including security services at the higher levels of protocol stack.

6. Desirable Security Features in E-Mail Confidentiality Sender Authentication Message Integrity Receiver Authentication

7. Confidentiality can be provided through cryptography Crytography: Encription and Decription. Encription can be done by using: Symmetric key technology(using DES or AES) Public key cryptography(using RES) Session key

8. SESSION KEY

9. SENDER AUTHENTICATION AND MESSAGE INTEGRITY

10. PRETTY GOOD PRIVACY(PGP) Three step process generally applied STEP 1: Calculate Message Digest STEP 2: Apply Symmetric key encryption STEP 3: Public key encryption

11. References www.wikipedia.org Textbook “Computer Networking: Fifth Edition, Kurose and Ross” Source for diagram of slide 8: www.google.comwww.google.com Source for diagram of slide 9: www.google.com and textbook: “Computer Networking Fifth Edition: Kurose and Ross”www.google.com

12. QUESTIONS ??????