If you have a PKI certificate in your Windows PC that you would like to use to log in to your OpenSSH-enabled Linux server, it can be a pain to figure out how to extract the public key from this file and convert it into a format OpenSSH can understand.
Penango is a Mozilla Firefox and Microsoft Internet Explorer plug-in which allows users to seamlessly use strong encryption to secure e-mails through popular web-based services such as Google Gmail. This guide is meant for the average computer user who would like to encrypt and decrypt emails to and from friends/family/coworkers without worrying about too much of the technical details.