De-identification in the context of "Honest broker"

An honest broker is an entity that keeps sets of private information but distributes parts of those sets to other entities who should not have access to the entire set. Honest brokers often work in clinical research with biological specimens; in that case, donors of specimens allow researchers to do research on those specimens, but typically want their specimen de-identified by having protected health information separated from it. The honest broker would keep both the specimen and associated protected health information, but only allow researchers to have access to the specimen without the protected health information.