Oh my- good luck with that-
Lenny might be either suspended
Or might be failed in that particular course
1) Go through the standard Chrome OS login screen (you'll need to setup a network, etc) and get to the web browser. It's OK if you login as guest.
2) Press [ Ctrl ] [ Alt ] [ T ] to get the crosh shell.
3) Use the shell command to get the shell prompt.
It seems that you have missed the necessary options for us to answer this question so I had to look for it. Anyway, here is the answer. The protocol that supports the encryption and decryption of e-mail messages is this: <span>Secure Multipurpose Internet Mail Extensions (S/MIME) and Pretty Good Privacy (PGP). Hope this helps.</span>