AIM Encrypt is insecure, DIY
AIMEncrypt.com's certificate or any other that anyone can download is a very insecure way to do encryption in AIM. Knowing the internals of public-key cryptography, everyone with the same key really isn't secure. You can do encryption with OpenSSL securely instead.
Creating certificates with OpenSSL on Linux/Unix platforms are quite easy. But if you're using Windows, not all hope is lost. I've looked everywhere for instructions to create your own self-signed certificate, and since there isn't really a page out there that did it, I wrote my own.
Here are some instructions to create your own self-signed certificate for AIM. You don't need anything special, I put up the binary that allows you to do it with OpenSSL. You can use any OpenSSL binary, I provide instructions on how to use your own binary as well. If the instructions scare you, there will be a program provided that can do it all for you. It asks you for some info you want in your certificate, and with a few clicks, you'll be on your way.
Then, after you create the .p12 package that AIM accepts, just import it and tell me what you think ;)
URL is at:
http://secure.sylikc.net:8080/self_signed/
or just http://sylikc.net/?secure, and find the HOWTO on the bottom.
Now then you won't have to use a freely downloadable (insecure) certificate, just DIY.