anchor.diff:  %%--------------------------------------------------------------------
   %%% Internal functions
   %%--------------------------------------------------------------------
  +default_options([]) ->
  +    [{rsa_padding, rsa_pkcs1_padding}];
  +default_options(Opts) ->
  +    case proplists:get_value(rsa_pad, Opts) of
  +        undefined ->
  +            case proplists:get_value(rsa_padding, Opts) of
  +                undefined ->
  +                    case lists:dropwhile(fun erlang:is_tuple/1, Opts) of
  +                        [Pad|_] ->
  +                            set_padding(Pad, Opts);
  +                        [] ->
  +                            set_padding(rsa_pkcs1_padding, Opts)
  +                    end;
  +                Pad ->
  +                    set_padding(Pad, Opts)
  +            end;
  +        Pad ->
  +            set_padding(Pad, Opts)
  +    end.
  +
  +set_padding(Pad, Opts) ->
  +    [{rsa_padding,Pad} | [{T,V} || {T,V} <- Opts,
  +                                   T =/= rsa_padding,
  +                                   T =/= rsa_pad]
  +    ].
  +
  +
   format_sign_key(Key = #'RSAPrivateKey'{}) ->
       {rsa, format_rsa_private_key(Key)};
   format_sign_key(#'DSAPrivateKey'{p = P, q = Q, g = G, x = X}) ->
  
positive.code:                                        CipherText :: binary() .
  encrypt_public(PlainText, #'RSAPublicKey'{modulus=N,publicExponent=E}, 
  	       Options) when is_binary(PlainText), is_list(Options) ->
      Padding = proplists:get_value(rsa_pad, Options, rsa_pkcs1_padding),
      crypto:public_encrypt(rsa, PlainText, [E,N], Padding).
  
  %%--------------------------------------------------------------------
  %%
  
negative.code:                                      PlainText :: binary() .
  decrypt_public(CipherText, #'RSAPublicKey'{modulus = N, publicExponent = E}, 
  	       Options) when is_binary(CipherText), is_list(Options)  ->
      crypto:public_decrypt(rsa, CipherText,[E, N], default_options(Options)).
  
  %%--------------------------------------------------------------------
  %% Description: Public key encryption using the public key.
  