private key loosed what to do !

Many one ask this question if i loose my private key what happen , each every bitcoin user know the coin from that address are gone ( some one take the coin )

How to avoid this in feature development . This is the one weakness in bitcoin ,

If some one bitcoin address that contain some bitcoin ( 1 or something ) the secret leaked ,

That the leaked address secret not any one used to take those coin from that address ,

only who is the real owner of that address he/she only spend those coin ,

this condition need ( if the secret leaked no problem condition need )

any ideas , algorithm , scripts , etc .......... discuss here it help feature development

Contribute : your  ideas , algorithm , scripts , etc ..........

Thank you all.................