anchor.diff:  %%
   %% DES3 - in cipher block chaining mode (CBC)
   %%
  +-spec des3_cbc_encrypt(iodata(), iodata(), iodata(), binary(), iodata()) ->
  +			     binary().
  +-spec des3_cbc_decrypt(iodata(), iodata(), iodata(), binary(), iodata()) ->
  +			     binary().
  +
   des3_cbc_encrypt(Key1, Key2, Key3, IVec, Data) ->
       des_ede3_cbc_encrypt(Key1, Key2, Key3, IVec, Data).
   des_ede3_cbc_encrypt(Key1, Key2, Key3, IVec, Data) ->
  
positive.code: %%
  %% DES - in cipher block chaining mode (CBC)
  %%
  des_cbc_encrypt(Key, IVec, Data) ->
      des_cbc_crypt(Key, IVec, Data, true).
  
  
negative.code: %% Returns the IVec to be used in the next iteration of 
  %% des_cbc_[encrypt|decrypt].
  %%
  -spec des_cbc_ivec(iodata()) -> binary().
  
  des_cbc_ivec(Data) when is_binary(Data) -> 
      {_, IVec} = split_binary(Data, size(Data) - 8),
      IVec;
  