anchor.diff:  hide(SharedSecret, Authenticator, Password)
   		when length(SharedSecret) > 0, length(Authenticator) == 16,
   		length(Password) div 16 >= 1, length(Password) div 16 =< 8,
  -		length(Password) rem 16 == 0 -> 
  +		length(Password) rem 16 == 0 ->
   	hide(SharedSecret, Authenticator, Password, []).
   
   -spec unhide(SharedSecret :: string(), Authenticator :: [byte()],
  
positive.code: %%% @end
  %%%
  %%% Copyright (c) 2011-2014, Motivity Telecom
  %%% 
  %%% All rights reserved.
  %%% 
  %%% Redistribution and use in source and binary forms, with or without
  %%% modification, are permitted provided that the following conditions
  %%% are met:
  %%% 
  %%%    - Redistributions of source code must retain the above copyright
  %%%      notice, this list of conditions and the following disclaimer.
  %%%    - Redistributions in binary form must reproduce the above copyright
  %%%      notice, this list of conditions and the following disclaimer in
  %%%      the documentation and/or other materials provided with the 
  %%%      distribution.
  %%%    - Neither the name of Motivity Telecom nor the names of its
  %%%      contributors may be used to endorse or promote products derived
  
negative.code: unhide(SharedSecret, Authenticator, UserPassword)
  		when length(SharedSecret) > 0, length(Authenticator) == 16,
  		length(UserPassword) div 16 >= 1, length(UserPassword) div 16 =< 8,
  		length(UserPassword) rem 16 == 0 ->
  	unhide(SharedSecret, Authenticator, UserPassword, []).
  
  %%----------------------------------------------------------------------
  