diff --git a/src/ecu_ed25519.erl b/src/ecu_ed25519.erl
index 4db11cb..512bd43 100644
--- a/src/ecu_ed25519.erl
+++ b/src/ecu_ed25519.erl
@@ -11,12 +11,12 @@
 -type pt_affine() :: {non_neg_integer(), non_neg_integer()}. %% {X, Y}
 -type pt_hom_ext() :: {non_neg_integer(), non_neg_integer(),
                        non_neg_integer(), non_neg_integer()}. %% {X, Y, Z, T}
--type pt_compressed() :: <<_:32>>. %% Y coord + odd/even X.
+-type pt_compressed() :: <<_:256>>. %% Y coord + odd/even X.
 
 -type pt() :: pt_affine() | pt_hom_ext() | pt_compressed().
 
 %% -type fld_elem() :: 0..(?P-1).
--type scalar()   :: 0..(?N-1).
+-type scalar() :: 0..(?N-1).
 
 -define(D, 16#52036CEE2B6FFE738CC740797779E89800700A4D4141D8AB75EB4DCA135978A3).
 -define(X, 16#216936D3CD6E53FEC0A4E231FDD6DC5C692CC7609525A7B2C9562D608F25D51A).
@@ -33,6 +33,8 @@
 -define(SUB(A, B), ((A - B + ?P) rem ?P)).
 -define(DIV(A, B), f_div(A, B)).
 
+-export_type([pt/0, scalar/0]).
+
 -export([on_curve/1, p/0, n/0, pt_eq/2,
          scalar_mul/2, scalar_mul_base/1,
          scalar_mul_noclamp/2, scalar_mul_base_noclamp/1,
@@ -76,14 +78,14 @@ n() -> ?N.
 
 -define(TWO_POW_255_MINUS_1, 16#7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF).
 
--spec compress(P :: pt()) -> <<_:32>>.
+-spec compress(P :: pt()) -> pt_compressed().
 compress(<<_:32/binary>> = P) -> P;
 compress({_, _, _, _} = P)    -> compress(to_affine(P));
 compress({X, Y}) ->
   V = (Y band ?TWO_POW_255_MINUS_1) bor ((X band 1) bsl 255),
   <<V:256/little>>.
 
--spec decompress(<<_:32>>) -> pt_hom_ext().
+-spec decompress(pt_compressed()) -> pt_hom_ext().
 decompress(<<Y0:256/little>>) ->
   X0 = Y0 bsr 255,
   Y  = Y0 band ?TWO_POW_255_MINUS_1,
diff --git a/src/ecu_eddsa.erl b/src/ecu_eddsa.erl
index 4d383a5..ee85ecb 100644
--- a/src/ecu_eddsa.erl
+++ b/src/ecu_eddsa.erl
@@ -16,23 +16,22 @@
 %%
 %% The keypair is returned as a map with keys 'public' and 'secret'.
 %% @end
--spec sign_keypair() -> #{ atom() => binary() }.
+-spec sign_keypair() -> #{ public => binary(), secret => binary() }.
 sign_keypair() ->
   Secret = crypto:strong_rand_bytes(32),
-  <<Seed:32/bytes, _/binary>> = crypto:hash(sha512, Secret),
+  <<Seed:32/binary, _/binary>> = crypto:hash(sha512, Secret),
 
-  Pub = ecu_ed25519:scalar_mul_base(Seed),
+  Pub = ecu_ed25519:compress(ecu_ed25519:scalar_mul_base(Seed)),
   #{public => Pub, secret => <<Secret:32/binary, Pub:32/binary>>}.
 
 %% @doc sign_seed_keypair/1 computes the signing keypair from a seed.
 %%
 %% The keypair is returned as a map with keys 'public' and 'secret'.
 %% @end
--spec sign_seed_keypair(Seed :: <<_:32>>) -> #{ atom() => binary() }.
+-spec sign_seed_keypair(Secret :: <<_:256>>) -> #{ public => binary(), secret => binary() }.
 sign_seed_keypair(Secret) ->
-  <<Seed:32/bytes, _/binary>> = crypto:hash(sha512, Secret),
+  <<Seed:32/binary, _/binary>> = crypto:hash(sha512, Secret),
   Pub = ecu_ed25519:compress(ecu_ed25519:scalar_mul_base(Seed)),
-%%   Pub = enacl:crypto_ed25519_scalarmult_base(Seed),
 
   #{public => Pub, secret => <<Secret:32/binary, Pub:32/binary>>}.
 
@@ -41,7 +40,7 @@ sign_seed_keypair(Secret) ->
 %% Given a message `Msg' and a secret key `SK' the function will sign the
 %% message and return a signed message `SM'.
 %% @end
--spec sign(Msg :: iodata(), SK :: <<_:32>> | <<_:64>>) -> SM :: binary().
+-spec sign(Msg :: iodata(), SK :: <<_:256>> | <<_:512>>) -> SM :: binary().
 sign(Msg, SK) ->
   BinMsg = iolist_to_binary(Msg),
   Sig = sign_detached(Msg, SK),
@@ -54,12 +53,12 @@ sign(Msg, SK) ->
 %% `{error, failed_verification}' depending on the correctness of the
 %% signature.
 %% @end
--spec sign_open(SMsg :: binary(), PK :: <<_:32>>) ->
+-spec sign_open(SMsg :: binary(), PK :: <<_:256>>) ->
     {ok, Msg :: binary()} | {error, failed_verification}.
 sign_open(<<Sig:64/binary, BinMsg/binary>>, PK) ->
-  <<R:32/bytes, Ss:32/bytes>> = Sig,
+  <<R:32/binary, Ss:32/binary>> = Sig,
 
-  Ks0 = crypto:hash(sha512, <<R/bytes, PK/bytes, BinMsg/bytes>>),
+  Ks0 = crypto:hash(sha512, <<R/binary, PK/binary, BinMsg/binary>>),
   Ks = ecu_ed25519:scalar_reduce(Ks0),
 
   LHS = ecu_ed25519:scalar_mul_base_noclamp(Ss),
@@ -77,7 +76,7 @@ sign_open(<<Sig:64/binary, BinMsg/binary>>, PK) ->
 %% Given a message `Msg' and a secret key `SK' the function will compute the
 %% digital signature `Sig'.
 %% @end
--spec sign_detached(Msg :: iodata(), SK :: <<_:32>>) -> Sig :: binary().
+-spec sign_detached(Msg :: iodata(), SK :: <<_:256>> | <<_:512>>) -> Sig :: binary().
 sign_detached(Msg, SK) ->
   BinMsg = iolist_to_binary(Msg),
   <<Secret:32/binary, _/binary>> = SK,
@@ -119,12 +118,12 @@ sign_detached(Msg, SK) ->
 %% function computes true iff the `Sig' is valid for `Msg' and `PK'; and,
 %% false otherwise.
 %% @end
--spec sign_verify_detached(Sig :: <<_:64>>, Msg :: iodata(), PK :: <<_:32>>) -> boolean().
+-spec sign_verify_detached(Sig :: <<_:512>>, Msg :: iodata(), PK :: <<_:256>>) -> boolean().
 sign_verify_detached(Sig, Msg, PK) ->
   BinMsg = iolist_to_binary(Msg),
-  <<R:32/bytes, Ss:32/bytes>> = Sig,
+  <<R:32/binary, Ss:32/binary>> = Sig,
 
-  Ks0 = crypto:hash(sha512, <<R/bytes, PK/bytes, BinMsg/bytes>>),
+  Ks0 = crypto:hash(sha512, <<R/binary, PK/binary, BinMsg/binary>>),
   Ks = ecu_ed25519:scalar_reduce(Ks0),
 
   LHS = ecu_ed25519:scalar_mul_base_noclamp(Ss),
@@ -136,5 +135,5 @@ sign_verify_detached(Sig, Msg, PK) ->
 %% Clamp a 32-byte little-endian integer - i.e clear the lowest three bits
 %% of the first byte and clear the highest and set the second highest of
 %% the last byte (i.e. making it divisible by 8 and
-clamp(<<B0:8, B1_30:30/bytes, B31:8>>) ->
-  <<(B0 band 16#f8):8, B1_30/bytes, ((B31 band 16#7f) bor 16#40):8>>.
+clamp(<<B0:8, B1_30:30/binary, B31:8>>) ->
+  <<(B0 band 16#f8):8, B1_30/binary, ((B31 band 16#7f) bor 16#40):8>>.