[medina]

Not sure what you mean laws but there is certainly regulatory guidance that assessors will be using.

The agencies consider single-factor authentication, as the only control mechanism, to be inadequate for high-risk transactions involving access to customer information or the movement of funds to other parties. Financial institutions offering Internet-based products and services to their customers should use effective methods to authenticate the identity of customers using those products and services. The authentication techniques employed by the financial institution should be appropriate to the risks associated with those products and services. Account fraud and identity theft are frequently the result of single-factor (e.g., ID/password) authentication exploitation. Where risk assessments indicate that the use of single-factor authentication is inadequate, financial institutions should implement multifactor authentication, layered security, or other controls reasonably calculated to mitigate those risks.

https://www.ffiec.gov/pdf/authentication_guidance.pdf