Authentication context

Hello, 

In my application the user logs in using
biometrics.. my question is how to represent this in SAML?

For SAML 2.0 the following authentication
contexts are available:

main schema, common schema types, IP, IP password, Kerberos, mobile one-factor contract,
mobile one-factor unregistered,
mobile two-factor contract,
mobile two-factor unregistered,
nomadic telephony, personal telephony, PGP, password-protected transport,
password, previous session, smartcard, smartcard PKI, software PKI, SPKI, secure remote password, SSL certificate, telephony, authenticated telephony, time sync token, X.509, XML Signature

 

which one should be used for biometrics?

 

Thank you,

Filipa
Moura