Multi-Factor Key Derivation Function (MFKDF). (arXiv:2208.05586v1 [cs.CR])

We present the first general construction of a Multi-Factor Key Derivation
Function (MFKDF). Our function expands upon password-based key derivation
functions (PBKDFs) with support for using other popular authentication factors
like TOTP, HOTP, and hardware tokens in the key derivation process. In doing
so, it provides an exponential security improvement over PBKDFs with less than
12 ms of additional computational overhead in a typical web browser. We further
present a threshold MFKDF construction, allowing for client-side key recovery
and reconstitution …

factor key multi-factor