Honest Sampling

A rating agency may evaluate some property by sampling some set of assets upon which the property is based. For instance it might evaluate a mortgage-backed security (MBS) by sampling the underlying residential mortgages. Perhaps the sample is weighted by mortgage value. We focus here on the integrity of choosing the sample.

The evaluator of an MBS wants to make the rating credible. He thus commits himself to the following protocol to choose the sample. The evaluation will include crypto data in the evaluation that verifies an honest sample selection. This does not require trusting the evaluator in selecting the sample. It does nothing towards verifying the evaluation of a particular mortgage.

The original paperwork of each mortgage is digitized and a secure hash thereof produced.