Control which users/roles/privileges can see cost information on processes

Is it possible to make some processes private or restricted so only certain people can view it. Our users are concerned that if they add the financial details to specific roles, especially roles where only one person is employed such as a COO, those confidential details can be viewed by anyone. We would like to see an option for either keeping the costings restricted on a user basis, or by making the process private.

Having the capability to influence who can see Time and a separate setting for Cost.