Ind. Code § 5-1-4-27

Sec. 27. The state of Indiana does hereby pledge to and agree with the holders of any obligations issued under this chapter, and with those parties who may enter into contracts with an authority pursuant to the provisions of this chapter, that the state will not limit or alter the rights hereby vested in such authority until such obligations, together with the interest thereon, are fully met and discharged and such contracts are fully performed on the part of such authority. However, nothing in this section shall preclude such limitation or alteration if and when adequate provisions shall be made by law for the protection of the holders of such obligations of such authority or those entering into such contracts with such authority. An authority as agent for the state is authorized to include this pledge and undertaking for the state in such obligations or contracts.