All bonds of the authority shall be signed by its chairman or vice chairman, and the seal of the authority shall be affixed thereto and attested by its secretary or assistant secretary. The signatures of the chairman, vice chairman, secretary and assistant secretary may be facsimile signatures and a facsimile of the seal of the authority may be imprinted on the bonds if the board of directors, in its proceedings with respect to issuance of such bonds, provides for manual authentication of such bonds by a trustee or paying agent or by named individuals who are employees of the state and who are assigned to the Department of Finance or office of the State Treasurer. Delivery of bonds so executed shall be valid notwithstanding any changes in officers or in the seal of the authority after the signing and sealing of such bonds.