diff --git a/src/binary_formats.ml b/src/binary_formats.ml
index 772dd577..b77126d4 100644
--- a/src/binary_formats.ml
+++ b/src/binary_formats.ml
@@ -20,7 +20,12 @@
    - test them
    - some purpose (`TALER_SIGNATURE_XXX`) are missing
      exchange and gana master branch are not in sync
-     and we should use a specific git tag instead *)
+     and we should use a specific git tag instead
+
+   - clean up functor mess
+     don't have not hash thing be HashCode like
+   - have a make function for wrapped HashCode structs
+     make it take the relevant type *)
 
 module Taler_signatures = Include.Taler_signatures
 
diff --git a/src/management.ml b/src/management.ml
index dfe84277..ae8750be 100644
--- a/src/management.ml
+++ b/src/management.ml
@@ -75,35 +75,23 @@ let mk_future_denom denom_secmod_sign_f
 
 let mk_future_sign_key signkey_secmod_sign_f
     ({ pub; sign= _; stamp_start; stamp_expire; stamp_end } : Secmod_keys.t) =
-  let exchange_pub =
-    (* TODO
-       - I don't think its in crockford base 32 here
-         maybe SHA-512?
-         or maybe SHA-512 in crockford base 32
-         -> no, its not a hash here
-            need to change ugly binary_formats functor
-            to not mixup hashed values with others
-       - have a make function for wrapped HashCode structs
-         make it take the relevant type *)
-    let v = EddsaPublicKey.to_b32 pub in
-    Binary_formats.ExchangePublicKeyP.{ v= { v } }
-  in
   let signkey_secmod_sig =
     let open Binary_formats in
-    let ps =
-      let anchor_time =
-        TimeAbsoluteNBO.{ v= Util.ptime_to_int64_us stamp_start }
-      in
-      let duration =
-        let v =
-          Ptime.diff stamp_start stamp_expire
-          |> Util.ptime_of_span_exn
-          |> Util.ptime_to_int64_us
-        in
-        TimeRelativeNBO.{ v }
-      in
-      SigningKeyAnnouncementPS.{ exchange_pub; anchor_time; duration }
+    let exchange_pub =
+      ExchangePublicKeyP.{ v= { v= EddsaPublicKey.to_octets pub } }
     in
+    let anchor_time =
+      TimeAbsoluteNBO.{ v= Util.ptime_to_int64_us stamp_start }
+    in
+    let duration =
+      let v =
+        Ptime.diff stamp_start stamp_expire
+        |> Util.ptime_of_span_exn
+        |> Util.ptime_to_int64_us
+      in
+      TimeRelativeNBO.{ v }
+    in
+    let ps = SigningKeyAnnouncementPS.{ exchange_pub; anchor_time; duration } in
     ps |> Bin.to_string SigningKeyAnnouncementPS.bin |> signkey_secmod_sign_f
   in
   FutureSignKey.
diff --git a/src/types.ml b/src/types.ml
index ac07fe92..73c500dd 100644
--- a/src/types.ml
+++ b/src/types.ml
@@ -82,6 +82,8 @@ module EddsaPublicKey = struct
      converted to Crockford Base32. *)
   type t = Mirage_crypto_ec.Ed25519.pub
 
+  let to_octets t = Mirage_crypto_ec.Ed25519.pub_to_octets t
+
   let of_b32 s =
     let open Syntax in
     let open Mirage_crypto_ec in
@@ -90,13 +92,14 @@ module EddsaPublicKey = struct
     | Error e -> Fmt.error "%a" pp_error e
     | Ok pub -> Ok pub
 
-  let to_b32 pub = pub |> Mirage_crypto_ec.Ed25519.pub_to_octets |> B32.encode
+  let to_b32 t = B32.encode (to_octets t)
   let jsont = Jsont.of_of_string ~kind:"EddsaPublicKey" of_b32 ~enc:to_b32
 end
 
 module EddsaSignature : sig
   type t
 
+  val to_octets : t -> string
   val sign : key:Mirage_crypto_ec.Ed25519.priv -> string -> t
   val of_b32 : string -> (t, string) result
   val to_b32 : t -> string
@@ -108,6 +111,8 @@ end = struct
      They are signature over a c-struct like `TALER_xxxPS` + with a purpose *)
   type t = string
 
+  let to_octets t = t
+
   (* TODO key format
      is it exactly like in GNU_CRYPTO?
      endianess issue? *)
@@ -128,6 +133,13 @@ end
 module RsaPublicKey = struct
   type t = Mirage_crypto_pk.Rsa.pub
 
+  let to_octets ({ n; e } : Mirage_crypto_pk.Rsa.pub) =
+    let open Binary_formats.RsaPublicKey in
+    let header = { n_len= Z.size n; e_len= Z.size e } in
+    let v = { header; n; e } in
+    let s = Bin.to_string bin v in
+    s
+
   let of_b32 s =
     let open Syntax in
     let* s = B32.decode s in
@@ -135,20 +147,14 @@ module RsaPublicKey = struct
     let+ v = Mirage_crypto_pk.Rsa.pub ~n:v.n ~e:v.e |> unwrap_err_msg in
     v
 
-  let to_b32 ({ n; e } : Mirage_crypto_pk.Rsa.pub) =
-    let open Binary_formats.RsaPublicKey in
-    let header = { n_len= Z.size n; e_len= Z.size e } in
-    let v = { header; n; e } in
-    let s = Bin.to_string bin v in
-    let s = B32.encode s in
-    s
-
+  let to_b32 t = B32.encode (to_octets t)
   let jsont = Jsont.of_of_string ~kind:"RsaPublicKey" of_b32 ~enc:to_b32
 end
 
 module RsaSignature : sig
   type t
 
+  val to_octets : t -> string
   val sign : key:Mirage_crypto_pk.Rsa.priv -> string -> t
   val of_b32 : string -> (t, string) result
   val to_b32 : t -> string
@@ -156,6 +162,8 @@ module RsaSignature : sig
 end = struct
   type t = string
 
+  let to_octets t = t
+
   (* no Rsa.sign(?):
      decrypt is equivalent to sign *)
   let sign ~key s =