Microsoft researchers have devised a way for third parties to make use the vast amount of encrypted data stored in the cloud by companies and individuals, without them actually having access to it or learning anything about it (except for what can be deduced from the result).

use encrypted data

The solution involves a protocol for a Secure Data Exchange (SDE) that uses Secure Multi-Party Computation (MPC), and which removes the need of the third party decrypting (and, therefore, being able to peek into) the data before it is used in computations.

The owner of the data gives the keys to it to the buyer (or keys to part of it to the potential buyer) and the buyer uses them to decrypt the data inside a multiparty computation.

“All of the computation is performed in the cloud, and the computation itself is encrypted in such a way that not even the cloud knows what is being computed, which protects any of the buyer’s data used in the computation such as a proprietary algorithm. If everything goes as expected, the cloud reveals the decrypted results to the interested parties,” Microsoft’s John Roach explains.

In the paper describing the solution, the researchers offered several real-world business scenarios where a secure data exchange using their protocol can come in handy.

For example: A company that’s developing machine learning models that will assist primary care providers in choosing the best treatment plans for their patients needs data to develop and study their models. They want to buy anonymized patient medical records from hospitals to do that, but only if the data does not already fit the model.

“This could in theory be tested by running simple statistical tests comparing the model parameters with the data, but in practice not because the hospital is not willing to disclose its data before a deal has been made,” the researchers explained.

A secure data exchange of this kind can also provide a way for the buyer to try out a fragment of this data, so that he can make an informed decision about whether it will be worth to buy the entirety of the data.

The researchers’ solution is still in the concept phase but, according to Roach, they are planning to create – and publicly release – the tools that will allow the creation of secure data exchanges in the not-so-distant future.

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