diff --git a/src/devices.ml b/src/devices.ml
new file mode 100644
index 00000000..ac8339e2
--- /dev/null
+++ b/src/devices.ml
@@ -0,0 +1,11 @@
+let signkey = Secmod_keys.make ~name:"signkey"
+let exchange_key = Secmod_keys.make ~name:"exchange_key"
+let denom_key = Secmod_keys.make ~name:"denom_key"
+
+let denom =
+  let finally _key = () in
+  Vif.Device.v ~name:"denom" ~finally [] @@ fun () ->
+  let rsa_l = List.map Secmod_denom.make Config.coins in
+  rsa_l
+
+let v = Vif.Devices.[ signkey; exchange_key; denom_key; denom ]
diff --git a/src/management.ml b/src/management.ml
index 9ecb1b34..0d4b87e9 100644
--- a/src/management.ml
+++ b/src/management.ml
@@ -23,7 +23,7 @@ let mk_future_denom denom_secmod_sign_f
        pub;
        sign= _;
      } :
-      Secmod_denom.rsa_denom) =
+      Secmod_denom.t) =
   let denom_pub =
     DenominationKey.Rsa RsaDenominationKey.{ age_mask= 0; rsa_pub= pub }
   in
diff --git a/src/mte.ml b/src/mte.ml
index 596d759a..56974867 100644
--- a/src/mte.ml
+++ b/src/mte.ml
@@ -123,12 +123,5 @@ let () =
   in
   Miou_unix.run @@ fun () ->
   let env = () in
-  let devices =
-    Vif.Devices.
-      [
-        Secmod_keys.signkey_device; Secmod_keys.denom_device;
-        Secmod_denom.denom_device;
-      ]
-  in
   let middlewares = Vif.Middlewares.[] in
-  Vif.run ~cfg ~devices ~middlewares routes env
+  Vif.run ~cfg ~devices:Devices.v ~middlewares routes env
diff --git a/src/secmod_denom.ml b/src/secmod_denom.ml
index c4dfae40..99ca9002 100644
--- a/src/secmod_denom.ml
+++ b/src/secmod_denom.ml
@@ -1,6 +1,6 @@
 open Types
 
-type rsa_denom = {
+type t = {
   section_name: string;
   value: Amount.t;
   stamp_start: Ptime.t;
@@ -15,9 +15,11 @@ type rsa_denom = {
   sign: string -> RsaSignature.t;
 }
 
-let hash_pub _pub = "todo public key converted to Crockford Base32"
+let hash_pub _pub =
+  (* todo public key converted to Crockford Base32 *)
+  assert false
 
-let make_rsa_denom
+let make
     ({
        section_name;
        value;
@@ -62,9 +64,3 @@ let make_rsa_denom
     pub;
     sign;
   }
-
-let denom_device =
-  let finally _key = () in
-  Vif.Device.v ~name:"rsa_denom" ~finally [] @@ fun () ->
-  let rsa_l = List.map make_rsa_denom Config.coins in
-  rsa_l
diff --git a/src/secmod_keys.ml b/src/secmod_keys.ml
index 5e444231..41b890e6 100644
--- a/src/secmod_keys.ml
+++ b/src/secmod_keys.ml
@@ -28,10 +28,3 @@ let make ~name =
   let priv, pub = Mirage_crypto_ec.Ed25519.generate () in
   let sign s = EddsaSignature.sign ~key:priv s in
   { stamp_start; stamp_expire; stamp_end; pub; sign }
-
-let signkey_device = make ~name:"signkey"
-
-(* the actual exchange's signing key
-   signed by the secmod signkey *)
-let exchange_device = make ~name:"exchange"
-let denom_device = make ~name:"denom"