Forays by Google subsidiary DeepMind Health into the UK’s medical institutions have been characterized by two major themes. First, amazing results powered by cutting-edge AI; and second, a lack of transparency over the handling of the UK’s public-funded data. With the science going swimmingly, DeepMind Health is focusing more than ever on reassuring UK citizens that their medical records are in safe hands. Its latest plan is a public ledger that shows which bits of data it’s using; when; and for what purposes.

The initiative is called the “Verifiable Data Audit,” and was announced this week in a blogpost written by DeepMind co-founder Mustafa Suleyman and the company’s head of security and transparency, Ben Laurie. The Audit technology is not yet in place, but would keep a publicly accessible record of every time DeepMind accesses hospital data, using technology related to the blockchain.

“Each time there’s any interaction with data, we’ll begin to add an entry to a special digital ledger,” write Suleyman and Laurie. “That entry will record the fact that a particular piece of data has been used, and also the reason why — for example, that blood test data was checked against the NHS national algorithm to detect possible acute kidney injury.”

Like blockchain technologies, this information will be write-only — it can’t be edited after the fact or deleted. It will also make use of cryptographic proofs that will allow experts to verify the integrity of the data. Unlike most blockchain systems, though, the ledger won’t be distributed among members of the public, but stored by a number of entities including data processors like DeepMind Health and health care providers. The company says this won’t impede the verification process, and that the choice was made to make the ledger more efficient. Blockchain entities like Bitcoin are distributed among lots of different players require a lot of power (computing and literal) to compile and check — as much as a small country, according to some estimates.

Speaking to The Guardian, Nicola Perrin of the Wellcome Trust said the technology should create a “robust audit trail” for public health data managed by DeepMind. “One of the main criticisms about DeepMind’s collaboration with the Royal Free [Hospital Trust] was the difficulty of distinguishing between uses of data for care and for research,” said Perrin. “This type of approach could help address that challenge, and suggests they are trying to respond to the concerns.” DeepMind Health says it wants implement “the first pieces” of the audit later this year.