Banking Giant ING Is Quietly Becoming a Serious Blockchain Innovator

ING is out to prove that startups aren't the only ones that can advance blockchain cryptography.

ING has came up with a modified version called "Zero-knowledge range proofs," which can prove that a number is within a certain range without revealing exactly what that number is.

Zero-knowledge range proofs can be used to prove that someone has a salary within the range needed to attain a mortgage without revealing the actual figure, said Mariana Gomez de la Villa, global head of ING's blockchain program.

Now, building on its past work, ING is adding yet another wrinkle to enterprise blockchain privacy, leveraging a type of proof known as "Zero-knowledge set membership."

MIT math whiz and one of the co-founders of zcash, Madars Virza, revealed a vulnerability in last year's zero-knowledge range proofs paper.

ING has been invited to the table with the world's top cryptographers and will participate in an invite-only workshop in Boston seeking to standardize zero knowledge proofs, alongside the likes of MIT's Shafi Goldwasser.

In this way, ING is now part of a wide community of experts extending the scope of zero-knowledge proofs.

At the start of this year, University College of London's Jonathan Bootle and Stanford's Benedikt Bunz released "Bulletproofs," which dramatically improves proof performance and allows proving a much wider class of statements than just range proofs.

Taking the Quorum model a step further, ING designed its range proofs to be computationally less onerous than previous zero knowledge deployments and so faster to run on distributed ledgers.

"Zk-SNARKs, used in JPM Quorum, are known to be less efficient than the construction of zero knowledge proofs for a specific purpose, as is the case of zero-knowledge range proofs. Indeed, range proofs are at least an order of magnitude faster," said Gomez de la Villa.