Encryption Service has strange characters

Hello everyone

Using the Encryption library, the result of the '$encrypter->encrypt('This is a plain-text message!')', returns strange characters like this: 



[C�<��ɪ�˓T��H-9t�g噾��B7��/���d� ��Ɲ�'�y`�@��@��L�$��[�M����D�?Ʃ�h�zt�%�M\�hС����B!�)�



 is that correct?

I'm using version 4.0.2 stable

Thanks