Pretty Good Privacy built its reputation among grassroots groups on the Net, all of whom wanted their information locked safely away from prying eyeballs. Problem was, to get that security, users had to jump through several hoops to encrypt their documents and email. But on Tuesday, this scenario was retired as the company teamed with Qualcomm to build strong cryptography into the latter's popular email program, Eudora.
The result is a streamlined way for most netizens to encrypt, decrypt, and - if so desired - digitally sign email: Users have only to click on one or two buttons. Until now, most users have been loathe to use PGP and others of its ilk because the programs required users to launch a separate application to secure their email. Even with a plethora of books and tutorials on the subject, encrypted email with PGP is not part of the status quo.
"We added two new buttons in the Eudora toolbar. One is a little icon that looks like a locked envelope, and that's what you click to encrypt, and there's another one which looks like a quill on a piece of paper, and that's what you click to digitally sign," said Paul Lanyi, PGP product manager.
The Qualcomm implementation uses the recently released 5.0 version of PGP for Personal Privacy, which incorporates two different sets of encryption algorithms - IDEA with RSA and CAST with DSS/Diffie-Hellman - to allow for backward compatibility with previous versions of the encryption software and to keep with PGP's philosophy of encouraging open standards.
Behind the clicked buttons, the email crypto system will carry out the procedures netizens used to have to do in two separate programs. It uses Northern Telecom's CAST symmetric cipher to encrypt the plain text with a 128-bit algorithm. The key used to encrypt this text is then encrypted using the ElGamal variation of Diffie-Hellman, which can use as many as 4,096 bits to secure the key. In addition, users can elect to include digital signatures to verify that their messages are, in fact, from them - or that they haven't changed in transit.
Recipients of the messages will use their own private keys to unlock the session key used to encrypt the message.
Although PGP and Qualcomm can agree on encryption implementation in email, the industry at large seems to be at odds over how the email systems handle encrypted attachments to messages. Currently, a standard protocol for handling encrypted email attachments is up for debate. The problem currently is that unless recipients have an email program that recognizes an attachment as an encrypted message, they are left to launch their encryption software to separately decode the document. The industry is hoping to come up with a common way to handle this, so it happens automatically when the message is received.
There are several competing standards in use, one of which is PGP/MIME, which Eudora uses. Neither Netscape nor Microsoft implement PGP/MIME in their own email applications.
Since it is not a completed standard, there are several incompatible versions of S/MIME currently in use.
"The S/MIME spec, which we are helping to create, is not done. We will go with whatever the industry adopts," Lanyi said. "The IETF has not sanctioned a particular version of it; we will work with whatever version they develop."
As for which flavor of MIME will win out, it's too early to tell, say cypherpunks. "PGP/MIME and S/MIME [the only other serious contender] are in about the same place in the IETF," said Raph Levien, a cypherpunk activist wrote the Unix utility premail, which integrates PGP, anonymous remailers, and sendmail into a single package.
"In both cases, there is a tug-of-war between IETF people and the proprietary owners of the technology about who gets to control the evolution of the standard. Thus, it's far too early to count the chicken of an IETF standard for PGP/MIME as hatched."
