Trust on first use - Wikipedia

Trust on first use (TOFU), or trust upon first use (TUFU), is an authentication scheme[1] used by client software which needs to establish a trust relationship with an unknown or not-yet-trusted endpoint. In a TOFU model, the client will try to look up the endpoint's identifier, usually either the public identity key of the endpoint, or the fingerprint of said identity key, in its local trust data

[nunnun]

初回接続時にTrustするモデル。SSHなどで用いられる。