that would allow a secure path for communication between the Secretary, MA plans under this part, prescription drug plans under part D, and an eligible entity with a contract under section 1893 (such as a Medicare drug integrity contractor or an entity responsible for carrying out program integrity activities under this part and part D) for the purpose of enabling through such portal (or other successor technology)— (i) the referral by such plans of substantiated or suspicious activities, as defined by the Secretary, of a provider of services (including a prescriber) or supplier related to fraud, waste, and abuse for initiating or assisting investigations conducted by the eligible entity