The Centers for Disease Control (CDC) and IBM are collaborating on a blockchain-based system that could track public health issues like the ongoing opioid crisis.

The new system, which IBM and the CDC’s National Center for Health Statistics have tested using simulated data, could make it easier for the CDC to survey medical providers about data like the reasons patients visit and the symptoms they display. The CDC already collects much of that data through surveys like the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey, which collect patient visit information from doctors and hospitals around the country. Data from CDC surveys are currently used to study everything from how frequently patients seek care for sleep problems to how doctors are prescribing antibiotics and opioid painkillers.

Using the blockchain approach could make it easier to automatically collect the data, keep it secure, and log who’s accessed which parts of it.

“There’s a lot of transparency that blockchain seems to offer to us,” says Askari Rizvi, chief of the technical services branch of the CDC’s Division of Health Care Statistics.

A blockchain somewhat similar to the ones that power cryptocurrencies like bitcoin would store data about the medical files provided to the CDC. The blockchain wouldn’t store the data itself, but it would track who has access to which pieces of data, helping to safeguard potentially sensitive patient information, says David McElroy, a blockchain technical lead for IBM’s federal government unit.

Researchers, the CDC, and medical providers could all…