What About (Score 3, Insightful)

PGP key's? I thought people knew about and used these. With a pgp key, it is signed with an encrypted hash, and you have the option of encrypting the message along side it. Once this is done, you know an email is coming from a valid user because it contains their key. These are already used in workplaces around the world. Why implement a new system when one already exists? Not only does one exist it is more or less and open standard. Yeesh! I wish people would actually stop rebuilding the wheel in the software industry.