Final answer:
The incorrect requirement for internet banking authentication is open access to user data, which would compromise security instead of enhancing it.
Step-by-step explanation:
The question relates to the requirements given by the guidance for supplementing authentication in an internet banking environment. The options given are various security measures, but the one that is not a requirement is open access to user data.
In fact, open access to user data could potentially compromise the security of the online banking platform. Instead, guidelines typically require multi-factor authentication, encryption, and techniques like the Secure Socket Layer (SSL) to enhance security and protect user data.