Zero Knowledge Proofs and the Metaverse

Published on:

Dec 22, 2022

In the first week of December, 2022, the term “Metaverse” placed second in the Oxford English Dictionary’s competition for Word of the Year, a vote cast by over 300k people signifying a word or expression believed to have lasting cultural significance reflecting the ethos and moods of the past twelve months.

That “Goblin Mode’’ won first place likely says more about the post-pandemic atmosphere and the cohort that participated in the survey rather than global technology trends. Today, companies from Microsoft to Disney and celebrities from Elton John to Snoop Dogg have embraced the Metaverse as the next stage in the internet revolution and are planning accordingly.

According to Mathew Ball’s The Metaverse, the definitive explanation is “a massively scaled and interoperable network of real-time rendered 3D virtual worlds that can be experienced synchronously and persistently by an effectively unlimited number of users with an individual sense of presence, and with continuity of data, such as identity, history, entitlements, objects, communications, and payments.”

Likely boosted by the pandemic’s shutdowns in 2020 and the mandatory lockdowns and social distancing, interest in a collective virtual shared space has exploded, and today over 500 companies claim to be working on the Metaverse.

Though this widespread interest in the Metaverse is new, the concept was imagined earlier and described in fictional works like Snow Crash and Ready Player One. The notion for a realistic vision of the Metaverse officially entered the zeitgeist when Facebook, one of the largest technology companies in the world, changed its name to Meta in 2021, signifying its plan to go all-in on the concept.

Clearly the Metaverse as Ball describes it is not yet a reality due to a host of practical reasons including limitations in networking, computing power, and interoperability standards. A fully realized Metaverse will eventually allow for data privacy and the scalability necessary for participants to traverse numerous digital worlds with a 3D avatar along with their digital assets and privileges.

Despite current limitations, many in positions of power believe the concept and demand for such a virtual space will continue to grow. A survey conducted by McKinsey in mid 2022 of more than 3,400 consumers and executives led them to estimate that the metaverse has the potential for a $5 trillion market value by 2030. To many futurists, the Metaverse is envisioned as a parallel plane for human leisure, labor and existence.

‍

‍

Zero Knowledge Proofs

“Zero Knowledge Proof” (ZKP) is another term gaining wider recognition. As the Zero Knowledge industry blossoms over the next 12 months, the term “ZKP” could win next year’s Oxford English Dictionary’s expression of the year.

The concept for ZKPs was invented in the 1980’s by a trio of researchers at MIT, first described in their academic paper “The Knowledge Complexity of Interactive Proof-Systems”.

Until the mid 2010’s, Zero Knowledge Proofs were simply an umbrella term for a branch of cryptography considered too theoretical and expensive for practical use. This has changed, thanks in large part, to companies and protocols in the crypto and blockchain space, collectively known as Web3.

A Zero-Knowledge Proof is a protocol that allows one party (i.e a web-connected person or application) known as the Prover, to prove to another party, known as the Verifier, that they know a certain piece of information, without revealing anything about the content of that information. The highlighted section is where the “Zero Knowledge” aspect comes from, that is, no additional information is revealed to the Verifier apart from the proof of knowing the information.

Advances in computing hardware, algorithms, and software have made ZKPs more accessible than in their early, purely theoretical days.

While there are a number of types of Zero Knowledge Proofs, all their computation relies on the processing in some combination of massive amounts of mathematical primitives including Multi-scalar Multiplication (MSM), Number Theoretic Transform (NTT), and hash functions.

Putting the math aside, ZKPs are a way to prove you know something, own something, or have done something, without revealing any information about that something. This has the power to revolutionize a number of industries, especially those requiring private information to be shared across the web. It also allows for ‘yes-no’ answers to complex questions involving private data.

Today the Zero Knowledge Proof industry is dominated by companies in the Web3 space, where ZKPs are being developed and utilized for a number of use-cases. For blockchains and the metaverse, ZKPs have two essential applications: scalability and privacy.

‍

‍

Web3, the Metaverse and ZKP

A handy summation of the Web’s history is as follows:

Web1- “read only” internet
Web2 — “read and write” the internet
Web3 — “decentralize and own” your internet

Web2 is currently the most widely used iteration of the internet. By relying on centralized parties for access and content, users of Web2 do not own their own data, and nearly every online interaction relies on another party to host their content, provide services, or store user information, assets and value.

Web3 is a blockchain-based internet that emphasizes self-custody of digital assets and data. Users own their content and have control over their internet use. The drawback of Web3 is that nearly all blockchains are transparent and their ledgers are public data. The same mechanisms that provide transparency to users also makes privacy nearly nonexistent.

Both the Metaverse and Web3 can be considered successors to Web2. Though the Metaverse does not require blockchain at its core, many interrelated technologies including ownership of digital assets are expected to be used in the Metaverse, and its economy will almost certainly be enabled by digital currencies and non-fungible tokens (NFTs).

Zero Knowledge Proofs can be used to enable private transactions for both the Metaverse and blockchains, solving the problem of open and transparent ledgers that characterize Web3 and allow for data privacy in the Metaverse. For example, a user could provide a ZKP to prove they have the necessary funds to complete a transaction to another entity, without revealing their account balance or transaction history.

Zero Knowledge Proofs can also enable the creation of anonymous accounts when interacting with blockchains, or while using an avatar in the Metaverse. With a ZKP, users can prove they are the owner of an account without revealing their identity or other personal information.

In addition, Zero Knowledge Proofs enable private communication. Two parties may use a ZKP to prove to each other that they are the intended recipients of a message without revealing the content of the message itself.

Blockchains and the Metaverse are both dependent on advances in scalability. Blockchains are limited in space because they are designed to store data in a decentralized and distributed manner, with each network participant storing a copy of the entire blockchain. Thus, the amount of data that can be stored on a blockchain is limited by the amount of storage space available on a network’s participating computers. Similarly, the Metaverse will need a scaling solution to connect the many worlds and metagalaxies that make up a unified Metaverse.

Zero Knowledge Proofs solve the scaling issue for blockchains by allowing computation to take place in untrusted environments, with only their solutions put on-chain, along with a ZKP attesting that the computation was done according to the blockchain’s rules. ZKP can do the same for the Metaverse by allowing for the systems hosting Metaverse processing to offload their computation to delegated environments and attest to their accurate results upon their return.

Parts of Web3 already resemble a metaverse. Concepts and structures such as Decentralized Autonomous Organizations (DAOs) enabled by smart contracts allow for transparent voting, fractionalized ownership, digital sovereignty and self-determination for like-minded groups of people who wish to participate in joint ventures.

Non-Fungible Tokens (NFTs) allow for unique digital items to be logged and traded on the blockchain, while remaining fully owned and controlled by the user in whose account the NFT resides. These composable primitives may soon be used in the Metaverse to trade avatars or items like avatar skins, weapons, and clothing, and even access to special events or areas like digital entrance passes.

Blockchain games use Web3 technologies like cryptocurrencies and NFTs so that players can buy, sell, or trade in-game assets and enable players to own their game assets in a secure and transparent way.

A recent report predicts the blockchain gaming market to hit $65.7B by 2027, up from $4.6B in 2022. The increase in investments and funding in blockchain games in 2021 and 2022 have been identified as the core drivers of this projected market growth.

Web3, the companies building it, and the tools that enable it are likely to underpin many of the protocols that enable the realization of an open and connected Metaverse. In the same vein, the internet communications protocols that enable Web2 and Web3 are likely to be expanded upon to enable a global network of standards and protocols that govern interoperable connections between persistent 3D worlds.

‍

‍

A Zero Knowledge Revolution

Accessible ZKPs can already revolutionize a number of industries, some of which are relevant to the realization of a free and open Metaverse:

Identity: People can verify identity online to third parties including service providers and governments without the risk of their information being leaked.

Finance: Financial exchanges can verify their solvency without leaking confidential and proprietary information.

Voting: Votes can be verified in electronic elections while protecting the privacy of voters and ensuring a tamper-proof election.

Cybersecurity: Users can log into platforms without revealing their password to a centralized verifier.

Anonymous ownership: Digital assets, currencies and other property may be owned without divulging owner identity.

Machine Learning: Allow the owner of a Machine Learning algorithm to convince others about the results of the model without revealing any information about the ML model itself.

Data Integrity: ZKPs can prove that images, videos, and data sets are authentic to fight disinformation.

‍

Ready Player Zero: ZKPs’ Role in the Metaverse

The experiences that most closely resemble the metaverse today are multiplayer games that exist in Integrated Virtual World Platforms (IVWPs) like Roblox, Minecraft and Fortnite. These IVWPs are collectively the three largest virtual worlds that have ever existed, each with tens of millions of daily active players. However, due to the closed nature of their ecosystems, these games can be thought of as “Metagalaxys” rather than the Metaverse.

There are two common ways to run a multiplayer game:

Client-Server (as are the majority of today’s games including Fortnite, Roblox, and Minecraft)
Peer-to-Peer

The common client-server architecture requires the server to act as a centralized, authoritative service provider. Each player sends information to the server which, in turn, shares this information with all the other players of the game.

There are several drawbacks to the Client-Server model of game design that work against these models being used in the Metaverse:

Ownership: the server owns and maintains all in-game assets
Expense: many powerful servers are required to run sophisticated multiplayer game engines
Scalability: bottlenecks in scalability arise when there is a single point of relay between the server and the players as additional players participate in the game
Privacy: the server is an untrusted third party with knowledge of every player’s actions

Peer-to-Peer gaming architecture resolves some of these problems but introduces another: cheating. Players can provide dishonest information about their in-game status to each other to subvert the rules of the game.

Enter Zero Knowledge Proofs.

ZKPs can be used to provide a publicly verifiable proof for every move they make, signaling to all parties that the move was legal within the rules of the game.

A ZKP can also be used to prove ownership of in-game digital assets. This replaces the need for a server to verify ownership of game-related items.

Finally, ZKPs can solve for game scalability, as a number of moves or actions can be batched together in one proof, reducing the computation overhead and enabling more players to participate in a game.

The introduction of Zero Knowledge Proofs to Peer-to-Peer games may allow this architecture to become a core aspect of the Metaverse, as these improvements dramatically reduce costs by removing the need for expensive centralized servers. This enhanced architecture also allows for many more participants in shared virtual spaces, each acting as a server by verifying other player’s actions with publicly veritable ZKPs.

By definition, the metaverse will only become “the Metaverse” if it can support a large number of users experiencing the same events at the same time and in the same virtual place. While this vision of the metaverses’s future gaming architecture requires the processing of many ZKPs per second, enhancements in Zero Knowledge Hardware are close to making these realities possible.

‍

‍

Metaphysics of the Metaverse

Philosophically, the Metaverse may be likened to the ultimate expression of the three principles that English philosopher John Locke wrote about in his 1689 essay, Two Treatises of Government, upon which the United States constitution and other western governments’ legal foundations are based upon: life, liberty, and property.

While these concepts exist in the physical world, they are limited by real world constraints. Today humans live in physical bodies, constrained by the laws of the universe which can broadly be described as physics. In the Metaverse, there are no physical limitations.

It is also reasonable to ponder whether we humans fully own and control our lives. If we break the rules of society, the government can arrest us and even take away our lives for particularly egregious offenses. No offense in digital spaces (for the moment) subjects the offender to the risk of losing real world liberties, apart from being booted from the virtual environment.

Liberty means freedom, whether it be from something or to do something. In the western world, humans have liberty to a degree. However, there are limitations placed on us by laws, both of the universe and of man. For example, we are not free to exist without the means to support ourselves — therefore most people need to work for a living to make money. Even gaining entry to the Metaverse is predicated on having the money to access it.

In the digital realm of the metaverse, it is envisioned that we will not be limited by societal or physical laws. We will be able to experience infinite space and time because there are no traveling times necessary in digital arenas. A participant in the metaverse can instantly reach any digital realm they desire.

Property is, broadly speaking, stuff. Humans must obtain and spend money to get stuff. Though we can ‘own’ our stuff, in reality we control only some aspects of our properties. Laws are enforced by governments and police to protect property. Neglecting to pay taxes and insurance enables your stuff to be taken away. At the same time, FIAT money is controlled by governments, which introduces further destabilizing elements to its use over time.

Zero Knowledge Proofs enable the addition of another foundational structure of digital life: truth.

With ZKPs, people can secure their truths: identity, money, property, and liberty by holding their own private keys. Truth is the ultimate sovereign, as it defines the reality of the universe.

If a utopia exists, it is unlikely to belong to a physical space. When we think about the metaverse, we are inclined to think about it as a place. But it may be about a time when immersive digital worlds become the primary manner in which we live our lives, according to the more fully realized tenets of life, liberty, property and truth.

‍