Ethereum and Ernst & Young

In Forbes, more examples in the space, here using a zero-knowledge approach. 

Ernst & Young Doubles Down On Its Bet With Ethereum
Ben Jessel  Contributor
Crypto & Blockchain
I write about fintech and enterprise adoption of blockchain technology.

On December 19th 2019, the audit and consulting giant Ernst & Young announced the release of their “third-generation zero-knowledge proof blockchain technology” to the public domain as part of the firm’s effort to make public networks ready for enterprise adoption.

Ernst & Young’s advocacy of public blockchain network infrastructure, as opposed to permissioned and private networks (referred to as private networks going forward, for brevity), is notable given that the firm’s industry peers have either remained neutral on the public vs. private network debate or have voiced skepticism on the viability of public networks. ... "

SQRL for Website Login and Authentication

More on Steve Gibson's SQRL, read through a bit of his site, below the WP description.  He has a very useful weekly podcast on security called 'Security Now'.   That I have followed for several years.  A good place to stay up to date on current IT technology security topics. 

Note the use of zero-knowledge proofs in their SQRL system described below:

In the Wikipedia:

SQRL (pronounced "squirrel")[3] or Secure, Quick, Reliable Login (formerly Secure QR Login) is a draft open standard for secure website login and authentication. The software typically uses a link of the scheme sqrl:// or optionally a QR code, where a user identifies via a pseudonymous zero-knowledge proof rather than providing a user ID and password. This method is thought to be impervious to a brute force password attack or data breach. It shifts the burden of security away from the party requesting the authentication and closer to the operating system implementation of what is possible on the hardware, as well as to the user. SQRL was proposed by Steve Gibson of Gibson Research Corporation in October 2013 as a way to simplify the process of authentication without the risk of revelation of information about the transaction to a third party ..... '

Extensive Video tutorial on SQRL:   https://youtu.be/Y6J1Yt8YYj0  

Defining Zero Knowledge Proofs

Relatively short, definitional and largely non technical definition of zero-knowledge proofs.  Previously covered here, and under examination.  Useful for any kind of transaction.

Hacker Lexicon: What Are Zero-Knowledge Proofs?

How do you make blockchain and other transactions truly private? With mathematical models known as zero-knowledge proofs.

In digital security, the less stray information floating around the better. The fewer companies storing your financial records, the less likely they'll be exposed in a breach. But though there are lots of ways to cut down on data sharing and retention, there are some things services just need to know, right? Thanks to the cryptographic method known as “zero-knowledge proofs” that’s not always the case.  ... "  

And here, related, pointer to a paper, and considerably more technical piece:

You Can Now Prove a Whole Blockchain With One Math Problem – Really   By William Foxley in Coindesk

The Electric Coin Company (ECC) says it discovered a new way to scale blockchains with “recursive proof composition,” a proof to verify the entirety of a blockchain in one function. For the ECC and zcash, the new project, Halo, may hold the key to privacy at scale.

A privacy coin based on zero-knowledge proofs, referred to as zk-SNARKs, zcash’s current underlying protocol relies on “trusted setups.” These mathematical parameters were used twice in zcash’s short history: upon its launch in 2016 and first large protocol change, Sapling, in 2018. ... " 

DARPA and Zero Knowledge Proofs

Does make sense that this kind of capability would be generally useful.   A key kind of cybersecurity.

Generating zero-knowledge proofs for defense capabilities  by DARPA

There are times when the highest levels of privacy and security are required to protect a piece of information, but there is still a need to prove the information's existence and accuracy. For the Department of Defense (DoD), the proof could be the verification of a relevant capability. How can one verify this capability without revealing any sensitive details about it? In the commercial world, this struggle manifests itself across banking transactions, cybersecurity threat disclosure, and beyond. One approach to addressing this challenge in cryptography is with zero-knowledge proofs. A zero-knowledge proof is a method where one party can prove to another party that they know a certain fact without revealing any sensitive information needed to demonstrate that the fact is true.

"A zero-knowledge proof involves a statement of fact and the underlying proof of its accuracy," said Dr. Josh Baron, program manager in DARPA's Information Innovation Office (I2O). "The holder of the fact does not want to reveal the underlying information to convince its audience that the fact is accurate. Take, for example, a bank withdrawal. You may want a system that allows you to make a withdrawal without also having to share your bank balance. The system would need some way of verifying that there are sufficient funds to draw from without having to know the exact amount of money sitting within your account."

In recent years, there has been a marked increase in the efficiency and real-world use of zero-knowledge proofs. Most of these uses have been within the cryptocurrency domain where there is a need to provide certain verifiable data without revealing personal or other sensitive information. While useful in this context, the zero-knowledge proofs created are specialized for this task. They prioritize communication and verification efficiency but do not necessarily scale for transactions that are more complex. For highly complex proof statements like those that the DoD may wish to employ, novel and more efficient approaches are needed. .... '

Definitions:    https://en.wikipedia.org/wiki/Zero-knowledge_proof

Zero Knowledge Proofs

A good explanation of Zero Knowledge Proofs, starting with simple examples.  Examples of usage at the link. At the tag below there is also a Python implementation example.

Zero-knowledge proof
From Wikipedia, the free encyclopedia

In cryptography, a zero-knowledge proof or zero-knowledge protocol is a method by which one party (the prover) can prove to another party (the verifier) that they know a value x, without conveying any information apart from the fact that they know the value x. The essence of zero-knowledge proofs is that it is trivial to prove that one possesses knowledge of certain information by simply revealing it; the challenge is to prove such possession without revealing the information itself or any additional information.[1]  .... "

Zero Knowledge Proofs

Intriguing introduction to zero knowledge proofs using graphs, with implementing Python code. Technical, but worth a look.  " ... In this post we’ll get a strong taste for zero knowledge proofs by exploring the graph isomorphism problem in detail. In the next post, we’ll see how this relates to cryptography and the bigger picture. The goal of this post is to get a strong understanding of the terms “prover,” “verifier,” and “simulator,” and “zero knowledge” in the context of a specific zero-knowledge proof. Then next time we’ll see how the same concepts (though not the same proof) generalizes to a cryptographically interesting setting. ... "