How Email, Instant Messaging and Voip Work

Activity 12.5

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How do email, instant messaging, and Voice over Internet Protocol (VoIP) work? How is information using these technologies kept secure?

Benoit Courbin

CSCI 109 Allan Roy June 25th, 2012

Activity 12.5

2

Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks (Wikipedia, 2012).

SMTP (Simple Mail Transfer Protocol) is a TCP/IP protocol used in sending and receiving email. However, since it is limited in its ability to queue messages at the receiving end, it is usually used with one of two other protocols, POP3 or IMAP, that let the user save messages in a server mailbox and download them periodically from the server (Mathew, 2005). As is true of most other Internet applications, e-mail is a client/server application. E-mail passes through e-mail servers whose functions are to store, process, and send e-mail to its ultimate destination. ISPs and portals such as Yahoo! maintain e-mail servers to provide email functionality to their customers. ISP’s e-mail server use DNS servers to locate the IP addresses for the recipients of the e-mails sent. Encryption software, such as Pretty Good Privacy (PGP), is used to code messages so that they can be decoded only by the authorized recipients (Evans, Martin & Poatsy, 2010). This is the basis of how email, instant messaging and VoIP work. Next, there are several ways to use encryption. Web browser and email encryptions are the most common ones. Web browsers automatically encrypt data by using a secure or proxy server. The encrypted site has the identifiable address beginning with https, with the s standing for secure. This server then decrypts the data upon arrival. For emails, use of PGP is the common encryption of choice. This encrypts messages, personal files and folders. Hard drive encryption is also a common type of encryption. This...