Sending mail is a little more care free. There are some things you can do to make sure your
conversation is secure though. The first is to ensure your connection is secure (see section
Connection Security for more information). There are also methods to allow you to digitally
sign your messages, which guarantees that the message is from you and has not been
tampered with en route. And for maximum security, you can encrypt your messages to make
sure no one reads them.
Digital signatures prove who e-mail comes from, and that it has not been altered in transit. If
you establish the habit of using digital signatures for important e-mail, you will have a lot of
credibility if you ever need to disown forged mail that appears to be from you. They also allow
you to encrypt e-mail so that no one can read it except the recipient. PGP in particular offers
high levels of encryption which to break would require extreme computing power.
9.3.1 Digital Certificates
A digital certificate is unique to an individual, kind of like a drivers license or passport, and is
composed of 2 parts. These parts are a public and private key. The certificate is unique to
one person, and typically certificates are issued by a trusted Certificate Authority, or CA. The
list of Certificate Authorities you trust is distributed automatically (if you are a Microsoft
Windows User) by Windows Update and the list is accessible in your browser under
tools>internet options>content>certificates. You can go here to view certificates installed on
your machine (yours and others), and other certificate authorities you trust.
