diff --git a/src/binary_formats.ml b/src/binary_formats.ml
index 4037a7eb..7547bb34 100644
--- a/src/binary_formats.ml
+++ b/src/binary_formats.ml
@@ -466,6 +466,26 @@ module DenominationKeyAnnouncementPS = struct
     |> sealr
 end
 
+module SigningKeyAnnouncementPS = struct
+  (* purpose.purpose = TALER_SIGNATURE_SM_SIGNING_KEY *)
+  type t = {
+    exchange_pub: ExchangePublicKeyP.t;
+    anchor_time: TimeAbsoluteNBO.t;
+    duration: TimeRelativeNBO.t;
+  }
+
+  let bin =
+    let open Bin in
+    Purpose.make_bin Taler_signatures.sm_signing_key @@ fun purpose ->
+    record (fun _purpose exchange_pub anchor_time duration ->
+        { exchange_pub; anchor_time; duration })
+    |+ Purpose.field purpose
+    |+ field ExchangePublicKeyP.bin (fun t -> t.exchange_pub)
+    |+ field TimeAbsoluteNBO.bin (fun t -> t.anchor_time)
+    |+ field TimeRelativeNBO.bin (fun t -> t.duration)
+    |> sealr
+end
+
 module SingleWithdrawRequestPS = struct
   (* purpose.purpose = TALER_SIGNATURE_WALLET_RESERVE_WITHDRAW *)
   type t = {
@@ -947,15 +967,6 @@ module CoinPurseRefundConfirmationPS = struct
   }
 end
 
-module SigningKeyAnnouncementPS = struct
-  (* purpose.purpose = TALER_SIGNATURE_SM_SIGNING_KEY *)
-  type t = {
-    exchange_pub: ExchangePublicKeyP.t;
-    anchor_time: TimeAbsoluteNBO.t;
-    duration: TimeRelativeNBO.t;
-  }
-end
-
 module MasterDenominationKeyRevocationPS = struct
   (* purpose.purpose = TALER_SIGNATURE_MASTER_DENOMINATION_KEY_REVOKED *)
   type t = { h_denom_pub: DenominationHash.t }
diff --git a/src/management.ml b/src/management.ml
index cbc4a510..259c3bc3 100644
--- a/src/management.ml
+++ b/src/management.ml
@@ -46,15 +46,8 @@ let mk_future_denom denom_secmod_sign_f
   in
   let denom_secmod_sig =
     ps
-    |>
-    (* TODO implement
-       SigningKeyAnnouncementPS.bin *)
-    Bin.to_string Binary_formats.DenominationKeyAnnouncementPS.bin
-    |>
-    (* TODO sig type *)
-    (* Signature by the denomination security module
-       (not this denomination rsa signature) *)
-    denom_secmod_sign_f
+    |> Bin.to_string Binary_formats.DenominationKeyAnnouncementPS.bin
+    |> denom_secmod_sign_f
   in
   FutureDenom.
     {