Each director of the authority shall execute a surety bond in the sum of fifty thousand dollars, or, in lieu thereof, the chairman of the authority shall execute a blanket positive bond covering each director, executive and employee of the authority, each surety bond to be conditioned upon the faithful performance of the duties of the office or officers covered, to be executed by a surety company authorized to transact business in the state of Connecticut as surety and to be approved by the Attorney General and filed in the office of the Secretary of the State. The cost of each such bond shall be paid by the authority.