Legal help needed in Bangladesh and inferentially.

Hello. I live in US, and one of my freelancers lives in Bangladesh. I'm giving him access to a large database of email addresses and phone numbers, which he needs to work on. I would like to create an agreement with him, where he will promise to not try to sell or pass this database to anyone, and will delete it from his computer/s as soon the project is complete. Please let me know what kind of document you think will work best for preventing him to even think about not complying...