We all know that the Internet is becoming an increasingly insecure place. This is why the Privacy and Security Research Group (PSRG) of the Internet Research Task Force (IRTF) and the the Privacy-Enhanced Electronic Mail Working Group (PEM WG) of the Internet Engineering Task Force (IETF) set up this system of Privacy-Enhanced Mail.
Privacy-Enhanced Mail messages often begin with the following headers:
-----BEGIN PRIVACYENHANCED MESSAGE------
begin privacy-enhanced message proctype
privacyenhanced message proctype
begin privacyenhanced message
begin privacy-enhanced message
-----END PRIVACYENHANCED MESSAGE------
This form of mail uses encryption and message authentication processes. PEM is now an Internet standard. It allows Internet mail to be sent to another party in a safe fashion. The messages are sent in their original form, ensuring that people don’t tamper with them. Also, the person on the receiving end is able to verify that the message was sent to that individual. Finally, PEM ensures that the message is kept private and is not shared with unintended parties.
There are two different versions of PEM. One is written by Mark Riordan. The other one was written by Trusted Information Systems, Inc.