For explanation purposes, a good comparison of the communication between computers on the Internet is to relate it to a telephone conversation between two people.

What issues arise?

1.) Who are you speaking with?

In a phone conversation, what can you do to ensure the person who picks up the phone on the other line is really the person you intended to call? If you’ve never spoken to them before, this is increasingly difficult. What if the phone call is answered by an imposter, trying to fool you into thinking they are the person you are attempting to contact? Might your phone call have been intercepted and re-routed? Who are you giving your information to?

2.) Is Someone Listening to Your Conversation?

It is very easy to tap phone lines and have conversations monitored for an extended period of time with no detection. The Internet is no different. What if someone was tapping and recording your Internet usage, capturing your passwords, social security numbers, bank account numbers, credit card information, and confidential documents. Without encryption, the Internet would be an unusable resource today.

Two very real security issues for Internet correspondence arise.

1. Being sure you are connected to the right computers; are you really on your bank’s website or is it a phisher’s scam website?
2. Keeping your data safe and out of malicious hands during transit on the Internet.