let denomination_key_validity ~key dn =
  let open Denomination in
  let open Signatures.DenominationKeyValidity in
  verify key dn.master_sig
    {
      R.master= key;
      start= dn.stamp_start;
      expire_withdraw= dn.stamp_expire_withdraw;
      expire_spend= dn.stamp_expire_deposit;
      expire_legal= dn.stamp_expire_legal;
      value= dn.value;
      fee_withdraw= dn.fee_withdraw;
      fee_deposit= dn.fee_deposit;
      fee_refresh= dn.fee_refresh;
      fee_refund= dn.fee_refund;
      denom_hash= dn.h_pub;
    }