Background
This article is not intended to be a guide on GPG and/or email security. Please refer to the gnupg.org site for more info/details on GPG and a startpage search for how to setup GPG in your email client.
There are numerous methods to send encrypted email, GPG is one of the most trusted and widely used. GPG relies on the PKI (a set of public and private keys). The public key is widely available to anyone. The private key is kept confidential. If you wish to send me an encrypted message, you encrypt the message with my public key. This ensures that the only one who can decrypt the message is the person(s) who have the private key.
Details
The challenge in the above scenario is getting/finding the public key of the person you wish to send an encrypted message to. This is where keyservers come into the picture, keyservers are servers that simply store public keys. You can search the keyserver for a key and download the public key as needed - problem solved!
You can find public keys via keyservers by searching the keyserver, for example:
Once you have found the public key, download it and import it into your email application for use with its GPG functionality.
Notes
- Notice: please realize that sending an encrypted email only encrypts the body of your email, the sender (email), destination email, and subject are not encrypted (how would the email get to me if the destination email address is encrypted). This is a limitation of SMTP and inter-connectivity between SMTP servers in general. If you are sending information where all information is confidential please seek other forms of communication (e.g. write a letter or mail a MMC).
- the above keyservers work well if you know the public key id (XXXXXXXXXX in the example above). You can also search by name or email address to find the public key you are looking for.
