anchor.diff:  secretbox_open(CipherText, Nonce, Key) ->
       case iolist_size(CipherText) of
           K when K =< ?SECRETBOX_SIZE ->
  -          R = case enacl_nif:crypto_secretbox_open_b([s_box_zerobytes(), CipherText],
  +          R = case enacl_nif:crypto_secretbox_open_b([?S_BOXZEROBYTES, CipherText],
                                                        Nonce, Key) of
                     {error, Err} -> {error, Err};
                     Bin when is_binary(Bin) -> {ok, Bin}
                 end,
             bump(R, ?SECRETBOX_OPEN_REDUCTIONS, ?SECRETBOX_SIZE, K);
           _ ->
  -          case enacl_nif:crypto_secretbox_open([s_box_zerobytes(), CipherText], Nonce, Key) of
  +          case enacl_nif:crypto_secretbox_open([?S_BOXZEROBYTES, CipherText], Nonce, Key) of
                 {error, Err} -> {error, Err};
                 Bin when is_binary(Bin) -> {ok, Bin}
             end
  
positive.code:     enacl_nif:randombytes(N).
  
  %% Helpers
  p_zerobytes() ->
  	binary:copy(<<0>>, enacl_nif:crypto_box_ZEROBYTES()).
  
  p_box_zerobytes() ->
  	binary:copy(<<0>>, enacl_nif:crypto_box_BOXZEROBYTES()).
  
  s_zerobytes() ->
  	binary:copy(<<0>>, enacl_nif:crypto_secretbox_ZEROBYTES()).
  
  s_box_zerobytes() ->
  	binary:copy(<<0>>, enacl_nif:crypto_secretbox_BOXZEROBYTES()).
  
  bump(Res, Budget, Max, Sz) ->
      Reds =  (Budget * Sz) div Max,
      erlang:bump_reductions(max(1, Reds)),
  
negative.code: -define(CRYPTO_BOX_ZEROBYTES, 32).
  -define(P_ZEROBYTES, <<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0>>). %% 32 bytes of 0
  -define(CRYPTO_BOX_BOXZEROBYTES, 16).
  -define(P_BOXZEROBYTES, <<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0>>).  %% 16 bytes
  
  -define(CRYPTO_SECRETBOX_ZEROBYTES, 32).
  -define(S_ZEROBYTES, <<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0>>). %% 32 bytes
  -define(CRYPTO_SECRETBOX_BOXZEROBYTES, 16).
  -define(S_BOXZEROBYTES, <<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0>>). %% 16 bytes
  -define(CRYPTO_STREAM_KEYBYTES, 32).
  -define(CRYPTO_STREAM_NONCEBYTES, 24).
  
  