Phone (SMS) - Requires the sender to provide a phone number for the recipient.Knowledge-based authentication – Requires the signer to enter their Social Security Number and random identity questions will be generated by a third-party provider.If this password is lost or forgotten, it cannot be recovered. The password must be passed to the signer separate from the transaction. Signing password – Requires the signer to enter a predetermined password to sign the document.It is recommended that you only enable the verification methods(s) that your internal policy demands. These methods are configured on the Send page as an element of the recipient record. Various methods of signer verification can be enabled for your users, with this setting.