For the first time I thought I'd use a password that was all lower
case letters, but I got a warning I shouldn't do that.  Does that
mean a user could look at some file and tell by the encryption sequence
that the password was composed of letters only?  Why should all-
lower case be any less secure than a mixture of upper and lower, with
or without digits?  The message also suggests the use of "control
characters."  Does that mean I could use ^C or ^Z?  What's the deal?

henry nelson