Como eu digo "autenticação em dois fatores" em inglês

Português: autenticação em dois fatores, autenticação multifator, autenticação em múltiplos fatores.
Inglês: two-factor/ multi-factor authentication, 2-factor authentication, 2-step verification, two-step verification.

Exemplo 1: So how can you stay safe from hackers? Setting up two-factor authentication, or 2FA – also known as multi-factor authentication, or MFA (...) Ref. uk.news.yahoo

Exemplo 2: Use multi-factor authentication (/2-factor authentication/two-step verification) to reduce the impact of password compromises. Ref. ncsc.gov

Exemplo 3: 2-step verification (often shortened to 2SV) provides a way of 'double checking' that you really are the person you are claiming to be when you're using online services, such as banking, email or social media. Ref. ncsc.gov

Exemplo 4: (...) by highlighting the importance of Two-Step Verification (2SV) in protecting online accounts from cybercriminals. Ref. merseyside.police