Ch.13.4 Helpdesk: Keeping E-mail Secure

What's an e-mail server?

An e-mail server is a specialized computer that stores, processes, and sends e-mails.

Encryption

Encryption refers to the process of coding your e-mail so that only the person with the key to the code (the intended recipient) can decode (or decipher) and read the message. There are two basic types of encryption: private-key and public-key: In private-key encryption, only the two parties involved in sending the message have the code. The problem with private-key encryption is that if someone steals a copy of the code, the code is broken.

Instant Messaging

Like e-mail, instant messaging (IM) is a client/server application.

SMTP: A Client/Server Approach

Simple Mail Transfer Protocol (SMTP) is the protocol responsible for sending e-mails over the Internet. As in most other Internet applications, e-mail is a client/server application. On its way to its destination, your mail will pass through e-mail servers—specialized computers whose sole function is to store, process, and send e-mail.

What is SMTP?

Simple mail transfer protocol (SMTP) is the protocol responsible for sending e-mail messages from an e-mail client to an e-mail server.

When I attach a file to my e-mail, will SMTP send it to the e-mail server?

The multipurpose Internet mail extensions (MIME) protocol is responsible for sending e-mail file attachments.

How E-Mail Travels the Internet

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Public-Key Encryption

In public-key encryption, two keys, known as a key pair, are created. You use one key for coding and the other for decoding. The key for coding is distributed as a public key. Anyone wishing to send you a message codes it using your public key. When you receive the message, you use your private key to decode it. You are the only one who possesses the private key so it is very secure. Both keys are necessary to decode a message; if one key is lost, the other key cannot be used by itself. Public-key encryption is the most commonly used encryption on the Internet. One popular package is Pretty Good Privacy (PGP).

Will SMTP keep my e-mails safe?

No, SMTP cannot keep your e-mails safe, but there are other security measures like encryption that can keep your e-mails safe.

Do instant messaging (IM) services use secure data transmission software to provide security of data exchanged?

No, most instant messaging services don't use secure data transmission software. Hence it is not safe to exchange important data over IM.

Secure Data Transmission Software

Using encryption doesn't always solve the other problems associated with e-mail. Messages leave a trail as they travel through the Internet, and copies of messages can exist on servers for long periods of time. In addition, immediate reading of sensitive documents is often essential, but encryption software doesn't provide a means for confirming your messages have been delivered.

How do I perform encryption?

You can encrypt messages using private-key encryption. In private-key encryption, only the two parties involved in sending and receiving the message have the code.

Is there any other safer way to encrypt e-mails?

You can use public-key encryption. In public-key encryption, two keys are created, one key for encoding and the other for decoding.