Sec. 6. The bonds or notes:
(1) shall be executed by the manual or facsimile signature of the chairman or vice chairman of the authority;
(2) shall be attested by the manual or facsimile signature of the public finance director;
(3) shall be imprinted or impressed with the seal of the authority by any means;
(4) may be authenticated by a trustee, registrar, or paying agent; and
(5) constitute valid and binding obligations of the authority, even if the chairman, vice chairman, or public finance director whose manual or facsimile signature appears on the bonds or notes no longer holds that office.