Upon granting the application, the Registrar may grant it conditionally upon the applicant paying as an additional fee in respect of assurance of title such a sum of money as the Registrar considers to be a sufficient indemnity by reason of the imperfect nature of the evidence of title or as against any uncertain or doubtful claim or demand incident to or which may arise upon the title or any risk to which the Government may be exposed by granting the application.