diff --git a/src/bin_sig.ml b/src/bin_sig.ml
index 1c95cdcc..60257daf 100644
--- a/src/bin_sig.ml
+++ b/src/bin_sig.ml
@@ -77,13 +77,15 @@ module MK (R : sig
 
   val bin : r Bin.t
 end) : sig
+  open Crypto
+
   type r = R.r
   type t
 
-  val sign : key:Crypto.EddsaPrivateKey.t -> r -> t
+  val sign : key:EddsaPrivateKey.t -> r -> t
 
   (* Ok () on verification success *)
-  val verify : key:Crypto.EddsaPublicKey.t -> t -> r -> (unit, string) result
+  val verify : key:EddsaPublicKey.t -> t -> r -> (unit, string) result
   val jsont : t Jsont.t
   val caqti : t Caqti_type.t
 end = struct
@@ -102,7 +104,45 @@ end = struct
     | true -> Ok ()
 
   let jsont = EddsaSignature.jsont
-  let caqti : EddsaSignature.t Caqti_type.t = EddsaSignature.caqti
+  let caqti = EddsaSignature.caqti
+end
+
+module MK' (R : sig
+  type r
+  type key
+
+  val bin : r Bin.t
+end) : sig
+  open Crypto
+
+  type key = R.key
+  type r = R.r
+  type t
+
+  val sign : key:EddsaPrivateKey.t -> r -> t
+
+  (* Ok () on verification success *)
+  val verify : key:EddsaPublicKey.t -> t -> r -> (unit, string) result
+  val jsont : t Jsont.t
+  val caqti : t Caqti_type.t
+end = struct
+  open Crypto
+
+  type key = R.key
+  type r = R.r
+  type t = EddsaSignature.t
+
+  let bin = R.bin
+  let sign ~key r = EddsaSignature.sign ~key (Bin.to_string bin r)
+
+  let verify ~key t r =
+    let b = EddsaSignature.verify ~key t ~msg:(Bin.to_string bin r) in
+    match b with
+    | false -> Error "signature verification failure"
+    | true -> Ok ()
+
+  let jsont = EddsaSignature.jsont
+  let caqti = EddsaSignature.caqti
 end
 
 module DenominationKeyAnnouncement = struct
diff --git a/src/secmod.mli b/src/secmod.mli
index ba897b50..2c4340b2 100644
--- a/src/secmod.mli
+++ b/src/secmod.mli
@@ -2,6 +2,9 @@ open Crypto
 
 type t
 
+(*val sm_sign : t -> string -> eddsa_sig*)
+
+(* *)
 val get_sm_key_priv : t -> eddsa_priv
 val get_sm_key_pub : t -> eddsa_pub
 val get_signkeys : t -> Signkey_data.t list