Indiana Code Title 5. State and Local Administration § 5-1.2-8-23

(1) must have the same principal amounts, maturities, and interest rates as the bonds being issued;

(2) may be secured by a first mortgage lien on the educational facility being financed or by a first mortgage lien on or security interest in other real or personal property or funds acceptable to the authority subject to any exceptions that the authority may approve and created by a mortgage instrument or security agreement satisfactory to the authority;  and

(3) may be insured or guaranteed by others.