Visibility right based on 'Created By'

Hi,

Am looking to define security matrix, but not able to achieve visibility right based on 'created by', i.e. I want my user to see all the cases created by him (Where he may or may not be the owner of the record, also the records could be assigned to any user across the organization).

The only solution, I know to achieve this is to give the user Global Read privileges on cases. But this is not right.

Any help??

Thanks in advance

Rajni