Any governmental agency responsible for letting public contracts may promulgate rules concerning the confidentiality of:
(1) The agency's cost estimate for any public contracts prior to bidding; and
(2) The identity of contractors who have obtained proposals for bid purposes for a public contract.
If the agency's rules require that such information be kept confidential, an employee or officer of the agency who divulges such information to any unauthorized person shall be subject to disciplinary action. This section shall not be construed to require that cost estimates or bidders' lists be kept confidential.