1. ITIS 1210 Introduction to Web-Based Information Systems
Chapter 11
How Works

2. How Email Works Same technology as rest of the Internet
TCP breaks message into packets
IP delivers packets to correct address
TCP reassembles
Mailing lists send same message to multiple parties
Moderated lists are screened

3. How Email Works Can subscribe to mailing lists Directories are common
List server or listserv manager
Directories are common
White pages
Yellow pages
is not secure
Can be read by snoopers
Encryption necessary to ensure privacy

5. Simple Encryption Letter ASCII Quotient Remain Send H 72 6 60 E 69 5 960 E 69 5 9 59 L 76 4 64 O 79 7 67
Key = 12

6. Simple Encryption Received Quotient Remain ASCII Letter 60 6 78 N 59 578 N 59 5 9 74 J 64 4 82 R 67 7 85 U
Key = 13