Is ?two-step? authentication the same as ?two-factor? or ?multi-factor? authentication?
?Two-step? or ?multi-step? authentication is not the same as ?two-factor? or ?multi-factor?. ?Two-step? or ?multi-step? authentication involves the subsequent presentation of one or more authentication steps after the first authentication step is successfully performed. This approach is not the same as ?multi-factor? authentication, as even though the overall process may rely on multiple authentication methods, each step relies on a single authentication factor.
Refer to the Information Supplement: Multi-Factor Authentication Guidance, available under Guidance Documents in the PCI SSC Document Library, for further guidance.