Uhh Now Dont misunderstand me
As far as I know, While doing encryption only Try to export a certificate ya.
So that even u format, By Using that certificate.. U can recover..
I will advice as - Use PGP For encryption..
Download from -
www.pgp.com - ItS Free
Hey Know what ! Use Winzip v9.0 , Coz the new version supports Password protection As well as Encryption.too
U can have simple Winzip Encryption As well as Hi-Fi 128 & 256 Bit Cipher Encryption too..
Enjoy