When there's some statistical likelihood based on observations alone, then when the subject acts on the information that's just statistically-likely, then we use the term that the subject is trusting that the information is the case. If there is no generic fallback mechanism or verification after a query, then the trust is blind.

This is an essential element in any partially (dynamically) known system, which includes any distributed system, since information does not travel without some trust.

See Security.