Meanings of brute force method in English

We generated and tested a large number of human monoclonal antibodies (mAbs) against human RON.

She made an exhaustive search for the missing letters, but found none.

But an exhaustive search of the cabin floor discovered no key.

An exhaustive search of trousers' pockets revealed a combined capital of twenty-five cents.

But she made an exhaustive search of the premises, without result.

Yet an exhaustive search of that house had revealed no trace of him.

When that fails, hackers can use sheer brute force: algorithms can power their way through 8 billion password combinations a second.