70 ILCS 535/10
The Authority shall biennially designate a national or State bank or banks as depositories of its money. Such depositories shall be designated only within the State and upon condition that bonds approved as to form and surety by the Authority and at least equal in amount to the maximum sum expected to be on deposit at any one time shall be first given by such depositories to the Authority, such bonds to be conditioned for the safe keeping and prompt repayment of such deposits. When any of the funds of the Authority shall be deposited by the treasurer in any such depository, the treasurer and the sureties on his official bond shall, to such extent, be exempt from liability for the loss of any such deposited funds by reason of the failure, bankruptcy or any other act or default of such depository; provided that the Authority may accept assignments of collateral by any depository of its funds to secure such deposits to the same extent and conditioned in the same manner as assignments of collateral are permitted by law to secure deposits of the funds of any city.
70 ILCS 535/10