I have used
<cfheader name="Expires" value="#Now()#">
<cfheader name="Pragma" value="no-cache">
on secure home page as the first line of code as per your
suggestions.
But still problem continues...
When I click on sign out, I go to public home page. When I
prese browser back button, again secure home page is displayed with
all the data. Again when I refresh the page, it goes to login
screen.
Please advice on this.