diff --git a/src/aeso_ast_infer_types.erl b/src/aeso_ast_infer_types.erl
index e4dd957..97ce45e 100644
--- a/src/aeso_ast_infer_types.erl
+++ b/src/aeso_ast_infer_types.erl
@@ -148,12 +148,14 @@ global_env() ->
      {["Map", "delete"],         Fun([K, Map(K, V)], Map(K, V))},
      {["Map", "member"],         Fun([K, Map(K, V)], Bool)},
      {["Map", "size"],           Fun1(Map(K, V), Int)},
+     %% Crypto/Curve operations
+     {["Crypto", "ecverify"],    Fun([Hash, Address, SignId], Bool)},
      %% Strings
      {["String", "length"], Fun1(String, Int)},
      {["String", "concat"], Fun([String, String], String)},
-     {["String", "sha3"], Fun1(String, Int)},
+     {["String", "sha3"],   Fun1(String, Hash)},
      %% Conversion
-     {["Int", "to_str"], Fun1(Int, String)},
+     {["Int", "to_str"],     Fun1(Int, String)},
      {["Address", "to_str"], Fun1(Address, String)}
     ].
 
diff --git a/src/aeso_ast_to_icode.erl b/src/aeso_ast_to_icode.erl
index 77508c0..2a0321f 100644
--- a/src/aeso_ast_to_icode.erl
+++ b/src/aeso_ast_to_icode.erl
@@ -316,6 +316,12 @@ ast_body({map, _, Map, [Upd]}, Icode) ->
 ast_body({map, Ann, Map, [Upd | Upds]}, Icode) ->
     ast_body({map, Ann, {map, Ann, Map, [Upd]}, Upds}, Icode);
 
+%% Crypto
+ast_body(?qid_app(["Crypto", "ecverify"], [Msg, PK, Sig], _, _), Icode) ->
+    prim_call(?PRIM_CALL_CRYPTO_ECVERIFY, #integer{value = 0},
+              [ast_body(Msg, Icode), ast_body(PK, Icode), ast_body(Sig, Icode)],
+              [word, word, sign_t()], word);
+
 %% Strings
 %% -- String length
 ast_body(?qid_app(["String", "length"], [String], _, _), Icode) ->