Letters of credit issued by the Bank of North Dakota in connection with section 21-04-09 must be secured by collateral. A security interest is created and attaches when the Bank issues a letter of credit in connection with section 21-04-09. Filing is not required for perfection of the security interest created and it is entitled to priority as to all creditors. The board of directors of a financial institution seeking a letter of credit from the Bank shall execute a written agreement with the Bank, reflect approval of the agreement in the board of director’s minutes and, as of the date of execution of the agreement, keep a copy of the agreement as an official record.