is there someone to help

Hi,
I am currently using scp manually to update different files from one host to
3 other hosts : at connection my password is requested and I enter it

I want to setup crontab to do so. 

How can I configure scp to avoid password prompting. I understand I have to
use

scp -B -i identity_file cpThisFile [email protected]/targetFile

How do I generate identity_file for the 3 different targets and where should
it be created

The purpose is to propagate IMSS rules, copy /etc/hosts,
/etc/postfix/transportList etc from one master to slaves,

If full instruction and readymade scripts, same amount of points will be
available

Best Rgds,	
Biswajyoti Kar
Perot Systems TSI (India) Ltd.,
'Shivalaya',
Plot No. 123 EP-IP IInd Phase, 
Whitefield Indl Area BG
Phone: 28413000 Xtn. 2431