From: utzoo!decvax!cca!gwyn@Brl@sri-unix
Newsgroups: net.unix-wizards
Title: Re:  chown() of course
Article-I.D.: sri-unix.3097
Posted: Fri Sep  3 21:32:23 1982
Received: Thu Sep  9 06:12:44 1982

From:     Doug Gwyn 
Date:     31 Aug 82 2:22:50-EDT (Tue)
Users can cooperate to transfer a file via e.g.
$ mkdir /tmp/x
$ cp myfile /tmp/x/yourfile
$ chmod 700 /tmp/x/yourfile
$ chown you /tmp/x/yourfile
$ chmod 755 /tmp/x
$ mail you
Ok, it's in /tmp/x.  Mail me a note when you have it.

(later...)
$ rm -rf /tmp/x
The advantage of this is that you don't have to give any more access
to the other fellow than you intended (your login directory can still
be private, for example).  Also, I think it's foolproof since you
aren't going to remove it until you know that it has been received.