Zero-knowledge proof (#ZKP) is a set of tools that allow an item of information to be validated without the need to expose the #data that demonstrates it. This is possible thanks to a series of #cryptographic algorithms through which a ‘tester’ can mathematically demonstrate to a ‘verifier’ that a computational statement is correct without revealing any data.

In this way, it can be demonstrated that certain data are true without sharing them with a third party. For example, a user could show that he is of the appropriate age to access a product or service, without needing to reveal how many years old he is. Or a person could prove that he has a sufficient income to buy a product or service, without having to share the exact amount of money in his possession.
This #protocol makes it possible to create, for example, #identity authentication systems without the risk of information being stolen, as in order to prove a person’s identity it is not necessary to share any personal data.
But, how does it work?
An example is the real estate sector. Frequently, even before carrying out a visit, estate agents or rental companies can ask their potential tenants to share their latest pay cheques, bank statements or other sensitive personal documentation to guarantee that they have sufficient income to take on the cost. In this case, a system based on #ZKP could provide users with the possibility to demonstrate that they have sufficient funds without the need to share any private data with the estate agent.
Nonetheless, the technology has the potential to improve data #privacy and #security in a wide range of use-cases, from fraud prevention systems that require a user's age, to the use of anonymous data to feed into the Internet of Things (#IoT). The latter is also an example of the benefit this technology can provide to regulatory constraints such as #GDPR, the European data protection regulations.
Another use-case is the use of #ZKP technology to add another layer of security and privacy in #blockchain oracles. These IT tools allow #smartcontracts to update their status, with the incorporation of external information from verified sources in order to trigger scheduled orders or events. For example, make a payment when there is a certain amount of money in an account.

In these cases, #ZKP could facilitate the implementation of these systems guaranteeing, at the same time, the privacy of external data that should interact with the #blockchain in permitting a scheduled action to be triggered, without the need to share the data itself. This could be applied both in centralized systems, where the data’s origin is a trusted entity, such as a bank or regulator; or in #decentralized systems or #DApps, where trust is based solely on mathematical mechanisms.
For now, the technology finds itself at an early adoption stage and the international actors making advances with this #technology are still few. One of the challenges being faced is the absence of standards, systems, and homogeneous languages, which permit distinct actors to interact with services based on this technology, which is what would really make it possible to harness its potential.
Scalability is also another technical challenge that still needs to be addressed, as well as the high computing capacity that these algorithms currently require.
#ZKP can be the key to unleashing the true potential of technologies such as #AI and the #IoT in a decentralized and data-based future, where users can interact with other people, objects or companies in a secure and private way.
Date: 09/12/2022