v7 man page for xsend

XSEND, XGET, ENROLL(1)					      General Commands Manual					    XSEND, XGET, ENROLL(1)

NAME
       xsend, xget, enroll - secret mail

SYNOPSIS
       xsend person
       xget
       enroll

DESCRIPTION
       These  commands	implement a secure communication channel; it is like mail(1), but no one can read the messages except the intended recipi-
       ent.  The method embodies a public-key cryptosystem using knapsacks.

       To receive messages, use enroll; it asks you for a password that you must subsequently quote in order to receive secret mail.

       To receive secret mail, use xget.  It asks for your password, then gives you the messages.

       To send secret mail, use xsend in the same manner as the ordinary mail command.	(However, it will accept  only	one  target).	A  message
       announcing the receipt of secret mail is also sent by ordinary mail.

FILES
       /usr/spool/secretmail/*.key: keys /usr/spool/secretmail/*.[0-9]: messages

SEE ALSO
       mail (1)

BUGS
       It should be integrated with ordinary mail.  The announcement of secret mail makes traffic analysis possible.

															    XSEND, XGET, ENROLL(1)