Errata exists for this version of the document.

OPC UA supports the selection of several security modes: “None”, “Sign”, “SignAndEncrypt”. Security mode “None” can only be used with security Profile None. It is disabled for all other security Profiles. The choice of “Sign” or “SignAndEncrypt” is dependent on the CSMS, in some applications where data confidentiality is not required, “Sign” might be sufficient.