Section 53. Depositories of authority funds

In order to protect funds
  deposited by an authority all banks, bankers, trust companies  or  other
  persons  carrying on a banking business, organized under the laws of the
  state, are authorized to give to the authority an undertaking with  such
  sureties  as  shall be approved by the authority, faithfully to keep and
  pay over upon the order of the authority any such  deposits  and  agreed
  interest  thereon, or in lieu of said sureties, to deposit as collateral
  such securities and in such amounts as  may  be  agreed  upon  with  the
  authority  pursuant  to a collateral deposit agreement in form and terms
  satisfactory to the authority.   The collateral to  be  deposited  shall
  consist  of  securities  in which savings banks may legally invest funds
  within their control.