anchor.diff:  -export([ init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3 ]).
   
   start_link(KeyPath, PrivateKey) ->
  -  { ok, Pid } = gen_server:start_link({global, signature}, ?MODULE, [ KeyPath, PrivateKey ], []),
  -  % register(signature, Pid),
  +  { ok, Pid } = gen_server:start_link(?MODULE, [ KeyPath, PrivateKey ], []),
  +  register(signature, Pid),
     { ok, Pid }.
   
   init([ KeyPath, PrivateKey ]) ->
  
positive.code: 
  % Private Methods
  
  verify_signature(Message, DigSig, Key) ->
    case public_key:verify(Message, sha256, DigSig, Key) of
      true -> Message;
  
negative.code: 
  load_key_for_robot(RobotName, KeyPath) ->
    FullPath = io_lib:format("~s/~s_public.pem", [ KeyPath, RobotName ]),
    load_key(FullPath).
  
  load_key(FullPath) ->
    case filelib:is_regular(FullPath) of
      true ->
        { ok, PublicPemBin } = file:read_file(FullPath),
  