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As the Aztec network enters a new phase of development, "Alpha", transactions will be enabled if the governance system successfully passes a vote on the upgrade. This post outlines the security properties of this Alpha network and the rationale behind our approach.
Aztec is novel code — the bleeding edge of cryptography and blockchain technology. As the first decentralized L2 on Ethereum, Aztec is powered by a global network of sequencers and provers. Decentralization introduces some novel challenges in how security is addressed; there is no centralized sequencer to pause or a centralized entity who has power over the network. The rollout of the network reflects this, with distinct goals at each phase.
Ignition
Validate governance and decentralized block building work as intended on Ethereum Mainnet.
Alpha
Enable transactions at 1TPS, ~6s block times and improve the security of the network via continual ongoing audits and bug bounty. New releases of the alpha network are expected regularly to address any security vulnerabilities. Please note, every alpha deployment is distinct and state is not migrated between Alpha releases.
Beta
We will transition to Beta once the network scales to >10 TPS, with reduced block times while ensuring 99.9% uptime. Additionally, the transition requires no critical bugs disclosed via bug bounty in 3 months. State migrations across network releases can be considered.
TL;DR: The roadmap from Ignition to Alpha to Beta is designed to reflect the core team's growing confidence in the network's security.
This phased approach lets us balance ecosystem growth while building security confidence and steadily expanding the community of researchers and tools working to validate the network’s security, soundness and correctness.
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Ultimately, time in production without an exploit is the most reliable indicator of how secure a codebase is.
At the start of Alpha, that confidence is still developing. The core team believes the network is secure enough to support early ecosystem use cases and handle small amounts of value. However this is experimental alpha software and users should not deposit more value than they are willing to lose. Apps may choose to limit deposit amounts to mitigate risk for users.
Audits are ongoing throughout Alpha, with the goal to achieve dual external audits across the entire codebase.
The table below shows current security and audit coverage at the time of writing.
The main bug bounty for the network is not yet live, other than for the non-cryptographic L1 smart contracts as audits are ongoing. We encourage security researchers to responsibly disclose findings in line with our security policy .
As the audits are still ongoing, we expect to discover vulnerabilities in various components. The fixes will be packaged and distributed with the “v5” release.
If we discover a Critical vulnerability in “v4” in accordance with the following severity matrix, which would require the change of verification keys to fix, we will first alert the portal operators to pause deposits and then post a message on the forum, stating that the rollup has a vulnerability.
Aztec uses a hybrid execution model, handling private and public execution separately — and the security considerations differ between them.
As per the audit table above, it is clear that the Aztec Virtual Machine (AVM) has not yet completed its internal and external audits. This is intentional as all AVM execution is public, which allows it to benefit from a “Training Wheel” — the validator re-execution committee.
Every 72 seconds, a collection of newly proposed Aztec blocks are bundled into a "checkpoint" and submitted to L1. With each proposed checkpoint, a committee of 48 staking validators randomly selected from the entire set of validators (presently 3,959) re-execute all txs of all blocks in the checkpoint, and attest to the resulting state roots. 33 out of 48 attestations are required for the checkpoint proposal to be considered valid. The committee and the eventual zk proof must agree on the resultant state root for a checkpoint to be added to the proven chain. As a result, an attacker must control 33/48 of any given committee to exploit any bug in the AVM.
The only time the re-execution committee is not active is during the escape hatch, where the cost to propose a block is set at a level which attempts to quantify the security of the execution training wheel. For this version of the alpha network, this is set a 332M AZTEC, a figure intended to approximate the economic protection the committee normally provides, equivalent to roughly 19% of the un-staked circulating supply at the time of writing. Since the Aztec Foundation holds a significant portion of that supply, the effective threshold is considerably higher in practice.
A key design assumption is that just-in-time bribery of the sequencer committee is impractical and the only ****realistic attack vector is stake acquisition, not bribery.
Assuming a sequencer set size of 4,000 and a committee that rotates each epoch (~38.4mins) from the full sequencer set using a Fisher-Yates shuffle seeded by L1 RANDAO we can see the probability and amount of stake required in the table below.
To achieve a 99% probability of controlling at least one supermajority within 3 days, an attacker would need to control approximately 55.4% of the validator set - roughly 2,215 sequencers representing 443M AZTEC in stake. Assuming an exploit is successful their stake would likely de-value by 70-80%, resulting in an expected economic loss of approximately 332M AZTEC.
To achieve only a 0.5% probability of controlling at least one supermajority within 6 months, an attacker would need to control approximately 33.88% of the validator set.
The practical effect of this training wheel is that the network can exist while there are known security issues with the AVM, as long as the value an attacker would gain from any potential exploit is less than the cost of acquiring 332M AZTEC.
The training wheel allows security researchers to spend more time on the private execution paths that don’t benefit from the training wheel and for the network to be deployed in an alpha version where security researchers can attempt to find additional AVM exploits.
In concrete terms, the training wheel means the Alpha network can reasonably secure value up to around 332M AZTEC (~$6.5M at the time of writing).
Ecosystem builders should keep the above limits in mind, particularly when designing portal contracts that bridge funds into the network.
Portals are the main way value will be bridged into the alpha network, and as a result are also the main target for any exploits. The design of portals can allow the network to secure far higher value. If a portal secures > 332M AZTEC and allows all of its funds to be taken in one withdrawal without any rate limits, delays or pause functionality then it is a target for an AVM exploit attack.
If a portal implements a maximum withdrawal per user, pause functionality or delays for larger withdrawals it becomes harder for an attacker to steal a large quantum of funds in one go.
The Aztec Alpha code is ready to go. The next step is for someone in the community to submit a governance proposal and for the network to vote on enabling transactions. This is decentralization working as intended.
Once live, Alpha will run at 1 TPS with roughly 6 second block times. Audits are still ongoing across several components, so keep deposits small and only put in what you're comfortable losing.
On the security side, a 48-validator re-execution committee provides the main protection during Alpha, requiring 33/48 consensus on every 72-second checkpoint. Successfully attacking the AVM would require controlling roughly 55% of the validator set at a cost of around 332M AZTEC, putting the practical security ceiling at approximately $6.5M.
Alpha is about growing the ecosystem, expanding the security of the network, and accumulating the one thing no audit can shortcut: time in production. This is the network maturing in exactly the way it was designed to as it progresses toward Beta.
The Ignition Chain launched late last year, as the first fully decentralized L2 on Ethereum– a huge milestone for decentralized networks. The team has reinvented what true programmable privacy means, building the execution model from the ground up— combining the programmability of Ethereum with the privacy of Zcash in a single execution environment.
Since then, the network has been running with zero downtime with 3,500+ sequencers and 50+ provers across five continents. With the infrastructure now in place, the network is fully in the hands of the community, and the culmination of the past 8 years of work is now converging.
Major upgrades have landed across four tracks: the execution layer, the proving system, the programming language, Noir, and the decentralization stack. Together, these milestones deliver on Aztec’s original promise, a system where developers can write fully programmable smart contracts with customizable privacy.
The infrastructure is in place. The code is ready. And we’re ready to ship.
The execution layer delivers on Aztec's core promise: fully programmable, privacy-preserving smart contracts on Ethereum.
A complete dual state model is now in place–with both private and public state. Private functions execute client-side in the Private Execution Environment (PXE), running directly in the user's browser and generating zero-knowledge proofs locally, so that private data never leaves the original device. Public functions execute on the Aztec Virtual Machine (AVM) on the network side.
Aztec.js is now live, giving developers a full SDK for managing accounts and interacting with contracts. Native account abstraction has been implemented, meaning every account is a smart contract with customizable authentication rules. Note discovery has been solved through a tagging mechanism, allowing recipients to efficiently query for relevant notes without downloading and decrypting everything on the network.
Contract standards are underway, with the Wonderland team delivering AIP-20 for tokens and AIP-721 for NFTs, along with escrow contracts and logic libraries, providing the production-ready building blocks for the Alpha Network.
The proving system is what makes Aztec's privacy guarantees real, and it has deep roots.
In 2019, Aztec's cofounder Zac Williamson and Chief Scientist Ariel Gabizon introduced PLONK, which became one of the most widely used proving systems in zero-knowledge cryptography. Since then, Aztec's cryptographic backend, Barretenberg, has evolved through multiple generations, each facilitating faster, lighter, and more efficient proving than the last. The latest innovation, CHONK (Client-side Highly Optimized ploNK), is purpose-built for proving on phones and browsers and is what powers proof generation for the Alpha Network.
CHONK is a major leap forward for the user experience, dramatically reducing the memory and time required to generate proofs on consumer devices. It leverages best-in-class circuit primitives, a HyperNova-style folding scheme for efficiently processing chains of private function calls, and Goblin, a hyper-efficient purpose-built recursion acceleration scheme. The result is that private transactions can be proven on the devices people actually use, not just powerful servers.
This matters because privacy on Aztec means proofs are generated on the user's own device, keeping private data private. If proving is too slow or too resource-intensive, privacy becomes impractical. CHONK makes it practical.
Decentralization is what makes Aztec's privacy guarantees credible. Without it, a central operator could censor transactions, introduce backdoors, or compromise user privacy at will.
Aztec addressed this by hardcoding decentralized sequencing, proving, and governance directly into the base protocol. The Ignition Chain has proven the stability of this consensus layer, maintaining zero downtime with over 3,500 sequencers and 50+ provers running across five continents. Aztec Labs and the Aztec Foundation run no sequencers and do not participate in governance.
Noir 1.0 is nearing completion, bringing a stable, production-grade language within reach. Aztec's own protocol circuits have been entirely rewritten in Noir, meaning the language is already battle-tested at the deepest layer of the stack.
Internal and external audits of the compiler and toolchain are progressing in parallel, and security tooling including fuzzers and bytecode parsers is nearly finished. A stable, audited language means application teams can build on Alpha with confidence that the foundation beneath them won't shift.
The code for Alpha Network, a functionally complete and raw version of the network, is ready.
The Alpha Network brings fully programmable, privacy-preserving smart contracts to Ethereum for the first time. It's the culmination of years of parallel work across the four tracks in the Aztec Roadmap. Together, they enable efficient client-side proofs that power customizable smart contracts, letting users choose exactly what stays private and what goes public.
No other project in the space is close to shipping this.
The code is written. The network is running. All the pieces are in place. The governance proposal is now live on the forum and open for discussion. Read through it, ask questions, poke holes, and help shape the path forward.
Once the community is aligned, the proposal moves to a vote. This is how a decentralized network upgrades. Not by a team pushing a button, but by the people running it.
Programmable privacy will unlock a renaissance in onchain adoption. Real-world applications are coming and institutions are paying attention. Alpha represents the culmination of eight years of intense work to deliver privacy on Ethereum.
Now it needs to be battle-tested in the wild.
View the updated product roadmap here and join us on Thursday, March 5th, at 3 pm UTC on X to hear more about the most recent updates to our product roadmap.
In November 2025, the Aztec Ignition Chain went live as the first decentralized L2 on Ethereum. Since launch, more than 185 operators across 5 continents have joined the network, with 3,400+ sequencers now running. The Ignition Chain is the backbone of the Aztec Network; true end-to-end programmable privacy is only possible when the underlying network is decentralized and permissionless.
Until now, only participants from the $AZTEC token sale have been able to stake and earn block rewards ahead of Aztec's upcoming Token Generation Event (TGE), but that's about to change. Keep reading for an update on the state of the network and learn how you can spin up your own sequencer or start delegating your tokens to stake once TGE goes live.
The Ignition Chain launched to prove the stability of the consensus layer before the execution environment ships, which will enable privacy-preserving smart contracts. The network has remained healthy, crossing a block height of 75k blocks with zero downtime. That includes navigating Ethereum's major Fusaka upgrade in December 2025 and a governance upgrade to increase the queue speed for joining the sequencer set.
Over 30M $AZTEC tokens have been distributed to sequencers and provers to date. Block rewards go out every epoch (every 32 blocks), with 70% going to sequencers and 30% going to provers for generating block proofs.
If you don't want to run your own node, you can delegate your stake and share in block rewards through the staking dashboard. Note that fractional staking is not currently supported, so you'll need 200k $AZTEC tokens to stake.
The Ignition Chain launched as a decentralized network from day one. The Aztec Labs and Aztec Foundation teams are not running any sequencers on the network or participating in governance. This is your network.
Anyone who purchased 200k+ tokens in the token sale can stake or delegate their tokens on the staking dashboard. Over 180 operators are now running sequencers, with more joining daily as they enter the sequencer set from the queue. And it's not just sequencers: 50+ provers have joined the permissionless, decentralized prover network to generate block proofs.
These operators span the globe, from solo stakers to data centers, from Australia to Portugal.
Participating sequencers have maintained a 99%+ attestation rate since network launch, demonstrating strong commitment and network health. Top performers include P2P.org, Nethermind, and ZKV. You can see all block activity and staker performance on the Dashtec dashboard.
On January 26th, 2026, the community passed a governance proposal for TGE. This makes tokens tradable and unlocks the AZTEC/ETH Uniswap pool as early as February 11, 2026. Once that happens, anyone with 200k $AZTEC tokens can run a sequencer or delegate their stake to participate in block rewards.
Here's what you need to run a validator node:
These are accessible specs for most solo stakers. If you've run an Ethereum validator before, you're already well-equipped.
To get started, head to the Aztec docs for step-by-step instructions on setting up your node. You can also join the Discord to connect with other operators, ask questions, and get support from the community. Whether you run your own hardware or delegate to an experienced operator, you're helping build the infrastructure for a privacy-preserving future.
Solo stakers are the beating heart of the Aztec Network. Welcome aboard.
The $AZTEC token sale was the first of its kind, conducted entirely onchain with ~50% of the capital committed coming from the community. The sale was conducted completely onchain to ensure that you have control over your tokens from day one. As we approach the TGE vote, all token sale participants will be able to vote to unlock their tokens and make them tradable.
Immediately following the $AZTEC token sale, tokens could be withdrawn from the sale website into your personal Token Vault smart contracts on the Ethereum mainnet. Right now, token holders are not able to transfer or trade these tokens.
The TGE is a governance vote that decides when to unlock these tokens. If the vote passes, three things happen:
This decision is entirely in the hands of $AZTEC token holders. The Aztec Labs and Aztec Foundation teams, and investors cannot participate in staking or governance for 12 months, which includes the TGE governance proposal. Team and investor tokens will also remain locked for 1 year and then slowly unlock over the next 2 years.
The proposal for TGE is now live, and sequencers are already signaling to bring the proposal to a vote. Once enough sequencers have signaled, anyone who participated in the token sale will be able to connect their Token Vault contract to the governance dashboard to vote. Note, this will require you to stake/unstake and follow the regular 15-day process to withdraw tokens.
If the vote passes, TGE can go live as early as February 12, 2026, at 7am UTC. TGE can be executed by the first person to call the execute function to execute the proposal after the time above.
If you participated in the token sale, you don't have to do anything if you prefer not to vote. If the vote passes, your tokens will become available to trade at TGE. If you want to vote, the process happens in two phases:
Sequencers kick things off by signaling their support. Once 600 out of 1,000 sequencers signal, the proposal moves to a community vote.
After sequencers create the proposal, all Token Vault holders can vote using the voting governance dashboard. Please note that anyone who wants to vote must stake their tokens, locking their tokens for at least 15 days to ensure the proposal can be executed before the voter exits. Once signaling is complete, the timeline is as follows:
Vote Requirements:
Do I need to participate in the vote? No. If you don't vote, your tokens will become available for trading when TGE goes live.
Can I vote if I have less than 200,000 tokens? Yes! Anyone who participated in the token sale can participate in the TGE vote. You'll need to connect your wallet to the governance dashboard to vote.
Is there a withdrawal period for my tokens after I vote? Yes. If you participate in the vote, you will need to withdraw your tokens after voting. Voters can initiate a withdrawal of their tokens immediately after voting, but require a standard 15-day withdrawal period to ensure the vote is executed before voters can exit.
If I have over 200,000 tokens is additional action required to make my tokens tradable after TGE? Yes. If you purchased over 200,000 $AZTEC tokens, you will need to stake your tokens before they become tradable.
What if the vote fails? A new proposal can be submitted. Your tokens remain locked until a successful vote is completed, or the fallback date of November 13, 2026, whichever happens first.
I'm a Genesis sequencer. Does this apply to me? Genesis sequencer tokens cannot be unlocked early. You must wait until November 13, 2026, to withdraw. However, you can still influence the vote by signaling, earn block rewards, and benefit from trading being enabled.
This overview covers the essentials, but the full technical proposal includes contract addresses, code details, and step-by-step instructions for sequencers and advanced users.
Read the complete proposal on the Aztec Forum and join us for the Privacy Rabbit Hole on Discord happening this Thursday, January 22, 2026, at 15:00 UTC.
Follow Aztec on X to stay up to date on the latest developments.
The $AZTEC token sale was conducted entirely onchain to maximize transparency and fair distribution. Next steps for holders are as follows:
The $AZTEC token sale has come to a close– the sale was conducted entirely onchain, and the power is now in your hands. Over 16.7k people participated, with 19,476 ETH raised. A huge thank you to our community and everyone who participated– you all really showed up for privacy. 50% of the capital committed has come from the community of users, testnet operators and creators!
Now that you have your tokens, what’s next? This guide walks you through the next steps leading up to TGE, showing you how to withdraw, stake, and vote with your tokens.
The $AZTEC sale was conducted onchain to ensure that you have control over your own tokens from day 1 (even before tokens become transferable at TGE).
The team has no control over your tokens. You will be self-custodying them in a smart contract known as the Token Vault on the Ethereum mainnet ahead of TGE.
Your Token Vault contract will:
To create and withdraw your tokens to your Token Vault, simply go to the sale website and click on ‘Create Token Vault.’ Any unused ETH from your bids will be returned to your wallet in the process of creating your Token Vault.
If you have 200,000+ tokens, you are eligible to start staking and earning block rewards today.
You can stake by connecting your Token Vault to the staking dashboard, just select a provider to delegate your stake. Alternatively, you can run your own sequencer node.
If your Token Vault holds 200,000+ tokens, you must stake in order to withdraw your tokens after TGE. If your Token Vault holds less than 200,000 tokens, you can withdraw without any additional steps at TGE
Fractional staking for anyone with less than 200,000 tokens is not currently supported, but multiple external projects are already working to offer this in the future.
TGE is triggered by an onchain governance vote, which can happen as early as February 11th, 2026.
At TGE, 100% of tokens from the token sale will be transferable. Only token sale participants and genesis sequencers can participate in the TGE vote, and only tokens purchased in the sale will become transferrable.
Community members discuss potential votes on the governance forum. If the community agrees, sequencers signal to start a vote with their block proposals. Once enough sequencers agree, the vote goes onchain for eligible token holders.
Voting lasts 7 days, requires participation of at least 100,000,000 $AZTEC tokens, and passes if 2/3 vote yes.
Following a successful yes vote, anyone can execute the proposal after a 7-day execution delay, triggering TGE.
At TGE, the following tokens will be 100% unlocked and available for trading:
Join us Thursday, December 11th at 3 pm UTC for the next Discord Town Hall–AMA style on next steps for token holders. Follow Aztec on X to stay up to date on the latest developments.
The Ignition Chain launched late last year, as the first fully decentralized L2 on Ethereum– a huge milestone for decentralized networks. The team has reinvented what true programmable privacy means, building the execution model from the ground up— combining the programmability of Ethereum with the privacy of Zcash in a single execution environment.
Since then, the network has been running with zero downtime with 3,500+ sequencers and 50+ provers across five continents. With the infrastructure now in place, the network is fully in the hands of the community, and the culmination of the past 8 years of work is now converging.
Major upgrades have landed across four tracks: the execution layer, the proving system, the programming language, Noir, and the decentralization stack. Together, these milestones deliver on Aztec’s original promise, a system where developers can write fully programmable smart contracts with customizable privacy.
The infrastructure is in place. The code is ready. And we’re ready to ship.
The execution layer delivers on Aztec's core promise: fully programmable, privacy-preserving smart contracts on Ethereum.
A complete dual state model is now in place–with both private and public state. Private functions execute client-side in the Private Execution Environment (PXE), running directly in the user's browser and generating zero-knowledge proofs locally, so that private data never leaves the original device. Public functions execute on the Aztec Virtual Machine (AVM) on the network side.
Aztec.js is now live, giving developers a full SDK for managing accounts and interacting with contracts. Native account abstraction has been implemented, meaning every account is a smart contract with customizable authentication rules. Note discovery has been solved through a tagging mechanism, allowing recipients to efficiently query for relevant notes without downloading and decrypting everything on the network.
Contract standards are underway, with the Wonderland team delivering AIP-20 for tokens and AIP-721 for NFTs, along with escrow contracts and logic libraries, providing the production-ready building blocks for the Alpha Network.
The proving system is what makes Aztec's privacy guarantees real, and it has deep roots.
In 2019, Aztec's cofounder Zac Williamson and Chief Scientist Ariel Gabizon introduced PLONK, which became one of the most widely used proving systems in zero-knowledge cryptography. Since then, Aztec's cryptographic backend, Barretenberg, has evolved through multiple generations, each facilitating faster, lighter, and more efficient proving than the last. The latest innovation, CHONK (Client-side Highly Optimized ploNK), is purpose-built for proving on phones and browsers and is what powers proof generation for the Alpha Network.
CHONK is a major leap forward for the user experience, dramatically reducing the memory and time required to generate proofs on consumer devices. It leverages best-in-class circuit primitives, a HyperNova-style folding scheme for efficiently processing chains of private function calls, and Goblin, a hyper-efficient purpose-built recursion acceleration scheme. The result is that private transactions can be proven on the devices people actually use, not just powerful servers.
This matters because privacy on Aztec means proofs are generated on the user's own device, keeping private data private. If proving is too slow or too resource-intensive, privacy becomes impractical. CHONK makes it practical.
Decentralization is what makes Aztec's privacy guarantees credible. Without it, a central operator could censor transactions, introduce backdoors, or compromise user privacy at will.
Aztec addressed this by hardcoding decentralized sequencing, proving, and governance directly into the base protocol. The Ignition Chain has proven the stability of this consensus layer, maintaining zero downtime with over 3,500 sequencers and 50+ provers running across five continents. Aztec Labs and the Aztec Foundation run no sequencers and do not participate in governance.
Noir 1.0 is nearing completion, bringing a stable, production-grade language within reach. Aztec's own protocol circuits have been entirely rewritten in Noir, meaning the language is already battle-tested at the deepest layer of the stack.
Internal and external audits of the compiler and toolchain are progressing in parallel, and security tooling including fuzzers and bytecode parsers is nearly finished. A stable, audited language means application teams can build on Alpha with confidence that the foundation beneath them won't shift.
The code for Alpha Network, a functionally complete and raw version of the network, is ready.
The Alpha Network brings fully programmable, privacy-preserving smart contracts to Ethereum for the first time. It's the culmination of years of parallel work across the four tracks in the Aztec Roadmap. Together, they enable efficient client-side proofs that power customizable smart contracts, letting users choose exactly what stays private and what goes public.
No other project in the space is close to shipping this.
The code is written. The network is running. All the pieces are in place. The governance proposal is now live on the forum and open for discussion. Read through it, ask questions, poke holes, and help shape the path forward.
Once the community is aligned, the proposal moves to a vote. This is how a decentralized network upgrades. Not by a team pushing a button, but by the people running it.
Programmable privacy will unlock a renaissance in onchain adoption. Real-world applications are coming and institutions are paying attention. Alpha represents the culmination of eight years of intense work to deliver privacy on Ethereum.
Now it needs to be battle-tested in the wild.
View the updated product roadmap here and join us on Thursday, March 5th, at 3 pm UTC on X to hear more about the most recent updates to our product roadmap.
Privacy has emerged as a major driver for the crypto industry in 2025. We’ve seen the explosion of Zcash, the Ethereum Foundation’s refocusing of PSE, and the launch of Aztec’s testnet with over 24,000 validators powering the network. Many apps have also emerged to bring private transactions to Ethereum and Solana in various ways, and exciting technologies like ZKPassport that privately bring identity on-chain using Noir have become some of the most talked about developments for ushering in the next big movements to the space.
Underpinning all of these developments is the emerging consensus that without privacy, blockchains will struggle to gain real-world adoption.
Without privacy, institutions can’t bring assets on-chain in a compliant way or conduct complex swaps and trades without revealing their strategies. Without privacy, DeFi remains dominated and controlled by advanced traders who can see all upcoming transactions and manipulate the market. Without privacy, regular people will not want to move their lives on-chain for the entire world to see every detail about their every move.
While there's been lots of talk about privacy, few can define it. In this piece we’ll outline the three pillars of privacy and gives you a framework for evaluating the privacy claims of any project.
True privacy rests on three essential pillars: transaction privacy, identity privacy, and computational privacy. It is only when we have all three pillars that we see the emergence of a private world computer.
Transaction privacy means that both inputs and outputs are not viewable by anyone other than the intended participants. Inputs include any asset, value, message, or function calldata that is being sent. Outputs include any state changes or transaction effects, or any transaction metadata caused by the transaction. Transaction privacy is often primarily achieved using a UTXO model (like Zcash or Aztec’s private state tree). If a project has only the option for this pillar, it can be said to be confidential, but not private.
Identity privacy means that the identities of those involved are not viewable by anyone other than the intended participants. This includes addresses or accounts and any information about the identity of the participants, such as tx.origin, msg.sender, or linking one’s private account to public accounts. Identity privacy can be achieved in several ways, including client-side proof generation that keeps all user info on the users’ devices. If a project has only the option for this pillar, it can be said to be anonymous, but not private.
Computation privacy means that any activity that happens is not viewable by anyone other than the intended participants. This includes the contract code itself, function execution, contract address, and full callstack privacy. Additionally, any metadata generated by the transaction is able to be appropriately obfuscated (such as transaction effects, events are appropriately padded, inclusion block number are in appropriate sets). Callstack privacy includes which contracts you call, what functions in those contracts you’ve called, what the results of those functions were, any subsequent functions that will be called after, and what the inputs to the function were. A project must have the option for this pillar to do anything privately other than basic transactions.
Bitcoin ushered in a new paradigm of digital money. As a permissionless, peer-to-peer currency and store of value, it changed the way value could be sent around the world and who could participate. Ethereum expanded this vision to bring us the world computer, a decentralized, general-purpose blockchain with programmable smart contracts.
Given the limitations of running a transparent blockchain that exposes all user activity, accounts, and assets, it was clear that adding the option to preserve privacy would unlock many benefits (and more closely resemble real cash). But this was a very challenging problem. Zcash was one of the first to extend Bitcoin’s functionality with optional privacy, unlocking a new privacy-preserving UTXO model for transacting privately. As we’ll see below, many of the current privacy-focused projects are working on similar kinds of private digital money for Ethereum or other chains.
Now, Aztec is bringing us the final missing piece: a private world computer.
A private world computer is fully decentralized, programmable, and permissionless like Ethereum and has optional privacy at every level. In other words, Aztec is extending all the functionality of Ethereum with optional transaction, identity, and computational privacy. This is the only approach that enables fully compliant, decentralized applications to be built that preserve user privacy, a new design space that we see as ushering in the next Renaissance for the space.
Private digital money emerges when you have the first two privacy pillars covered - transactions and identity - but you don’t have the third - computation. Almost all projects today that claim some level of privacy are working on private digital money. This includes everything from privacy pools on Ethereum and L2s to newly emerging payment L1s like Tempo and Arc that are developing various degrees of transaction privacy
When it comes to digital money, privacy exists on a spectrum. If your identity is hidden but your transactions are visible, that's what we call anonymous. If your transactions are hidden but your identity is known, that's confidential. And when both your identity and transactions are protected, that's true privacy. Projects are working on many different approaches to implement this, from PSE to Payy using Noir, the zkDSL built to make it intuitive to build zk applications using familiar Rust-like syntax.
Private digital money is designed to make payments private, but any interaction with more complex smart contracts than a straightforward payment transaction is fully exposed.
What if we also want to build decentralized private apps using smart contracts (usually multiple that talk to each other)? For this, you need all three privacy pillars: transaction, identity, and compute.
If you have these three pillars covered and you have decentralization, you have built a private world computer. Without decentralization, you are vulnerable to censorship, privileged backdoors and inevitable centralized control that can compromise privacy guarantees.
What exactly is a private world computer? A private world computer extends all the functionality of Ethereum with optional privacy at every level, so developers can easily control which aspects they want public or private and users can selectively disclose information. With Aztec, developers can build apps with optional transaction, identity, and compute privacy on a fully decentralized network. Below, we’ll break down the main components of a private world computer.
A private world computer is powered by private smart contracts. Private smart contracts have fully optional privacy and also enable seamless public and private function interaction.
Private smart contracts simply extend the functionality of regular smart contracts with added privacy.
As a developer, you can easily designate which functions you want to keep private and which you want to make public. For example, a voting app might allow users to privately cast votes and publicly display the result. Private smart contracts can also interact privately with other smart contracts, without needing to make it public which contracts have interacted.
Transaction: Aztec supports the optionality for fully private inputs, including messages, state, and function calldata. Private state is updated via a private UTXO state tree.
Identity: Using client-side proofs and function execution, Aztec can optionally keep all user info private, including tx.origin and msg.sender for transactions.
Computation: The contract code itself, function execution, and call stack can all be kept private. This includes which contracts you call, what functions in those contracts you’ve called, what the results of those functions were, and what the inputs to the function were.
A decentralized network must be made up of a permissionless network of operators who run the network and decide on upgrades. Aztec is run by a decentralized network of node operators who propose and attest to transactions. Rollup proofs on Aztec are also run by a decentralized prover network that can permissionlessly submit proofs and participate in block rewards. Finally, the Aztec network is governed by the sequencers, who propose, signal, vote, and execute network upgrades.
A private world computer enables the creation of DeFi applications where accounts, transactions, order books, and swaps remain private. Users can protect their trading strategies and positions from public view, preventing front-running and maintaining competitive advantages. Additionally, users can bridge privately into cross-chain DeFi applications, allowing them to participate in DeFi across multiple blockchains while keeping their identity private despite being on an existing transparent blockchain.
This technology makes it possible to bring institutional trading activity on-chain while maintaining the privacy that traditional finance requires. Institutions can privately trade with other institutions globally, without having to touch public markets, enjoying the benefits of blockchain technology such as fast settlement and reduced counterparty risk, without exposing their trading intentions or volumes to the broader market.
Organizations can bring client accounts and assets on-chain while maintaining full compliance. This infrastructure protects on-chain asset trading and settlement strategies, ensuring that sophisticated financial operations remain private. A private world computer also supports private stablecoin issuance and redemption, allowing financial institutions to manage digital currency operations without revealing sensitive business information.
Users have granular control over their privacy settings, allowing them to fine-tune privacy levels for their on-chain identity according to their specific needs. The system enables selective disclosure of on-chain activity, meaning users can choose to reveal certain transactions or holdings to regulators, auditors, or business partners while keeping other information private, meeting compliance requirements.
The shift from transparent blockchains to privacy-preserving infrastructure is the foundation for bringing the next billion users on-chain. Whether you're a developer building the future of private DeFi, an institution exploring compliant on-chain solutions, or simply someone who believes privacy is a fundamental right, now is the time to get involved.
Follow Aztec on X to stay updated on the latest developments in private smart contracts and decentralized privacy technology. Ready to contribute to the network? Run a node and help power the private world computer.
The next Renaissance is here, and it’s being powered by the private world computer.
After eight years of solving impossible problems, the next renaissance is here.
We’re at a major inflection point, with both our tech and our builder community going through growth spurts. The purpose of this rebrand is simple: to draw attention to our full-stack privacy-native network and to elevate the rich community of builders who are creating a thriving ecosystem around it.
For eight years, we’ve been obsessed with solving impossible challenges. We invented new cryptography (Plonk), created an intuitive programming language (Noir), and built the first decentralized network on Ethereum where privacy is native rather than an afterthought.
It wasn't easy. But now, we're finally bringing that powerful network to life. Testnet is live with thousands of active users and projects that were technically impossible before Aztec.
Our community evolution mirrors our technical progress. What started as an intentionally small, highly engaged group of cracked developers is now welcoming waves of developers eager to build applications that mainstream users actually want and need.
A brand is more than aesthetics—it's a mental model that makes Aztec's spirit tangible.
Renaissance means "rebirth"—and that's exactly what happens when developers gain access to privacy-first infrastructure. We're witnessing the emergence of entirely new application categories, business models, and user experiences.
The faces of this renaissance are the builders we serve: the entrepreneurs building privacy-preserving DeFi, the activists building identity systems that protect user privacy, the enterprise architects tokenizing real-world assets, and the game developers creating experiences with hidden information.
This next renaissance isn't just about technology—it's about the ethos behind the build. These aren't just our values. They're the shared DNA of every builder pushing the boundaries of what's possible on Aztec.
Agency: It’s what everyone deserves, and very few truly have: the ability to choose and take action for ourselves. On the Aztec Network, agency is native
Genius: That rare cocktail of existential thirst, extraordinary brilliance, and mind-bending creation. It’s fire that fuels our great leaps forward.
Integrity: It’s the respect and compassion we show each other. Our commitment to attacking the hardest problems first, and the excellence we demand of any solution.
Obsession: That highly concentrated insanity, extreme doggedness, and insatiable devotion that makes us tick. We believe in a different future—and we can make it happen, together.
Just as our technology bridges different eras of cryptographic innovation, our new visual identity draws from multiple periods of human creativity and technological advancement.
Our new wordmark embodies the diversity of our community and the permissionless nature of our network. Each letter was custom-drawn to reflect different pivotal moments in human communication and technological progress.
Together, these letters tell the story of human innovation: each era building on the last, each breakthrough enabling the next renaissance. And now, we're building the infrastructure for the one that's coming.
We evolved our original icon to reflect this new chapter while honoring our foundation. The layered diamond structure tells the story:
The architecture echoes a central plaza—the Roman forum, the Greek agora, the English commons, the American town square—places where people gather, exchange ideas, build relationships, and shape culture. It's a fitting symbol for the infrastructure enabling the next leap in human coordination and creativity.
From the Mughal and Edo periods to the Flemish and Italian Renaissance, our brand imagery draws from different cultures and eras of extraordinary human flourishing—periods when science, commerce, culture and technology converged to create unprecedented leaps forward. These visuals reflect both the universal nature of the Renaissance and the global reach of our network.
But we're not just celebrating the past —we're creating the future: the infrastructure for humanity's next great creative and technological awakening, powered by privacy-native blockchain technology.
Join us to ask questions, learn more and dive into the lore.
Join Our Discord Town Hall. September 4th at 8 AM PT, then every Thursday at 7 AM PT. Come hear directly from our team, ask questions, and connect with other builders who are shaping the future of privacy-first applications.
Take your stance on privacy. Visit the privacy glyph generator to create your custom profile pic and build this new world with us.
Stay Connected. Visit the new website and to stay up-to-date on all things Noir and Aztec, make sure you’re following along on X.
The next renaissance is what you build on Aztec—and we can't wait to see what you'll create.
Aztec’s Public Testnet launched in May 2025.
Since then, we’ve been obsessively working toward our ultimate goal: launching the first fully decentralized privacy-preserving layer-2 (L2) network on Ethereum. This effort has involved a team of over 70 people, including world-renowned cryptographers and builders, with extensive collaboration from the Aztec community.
To make something private is one thing, but to also make it decentralized is another. Privacy is only half of the story. Every component of the Aztec Network will be decentralized from day one because decentralization is the foundation that allows privacy to be enforced by code, not by trust. This includes sequencers, which order and validate transactions, provers, which create privacy-preserving cryptographic proofs, and settlement on Ethereum, which finalizes transactions on the secure Ethereum mainnet to ensure trust and immutability.
Strong progress is being made by the community toward full decentralization. The Aztec Network now includes nearly 1,000 sequencers in its validator set, with 15,000 nodes spread across more than 50 countries on six continents. With this globally distributed network in place, the Aztec Network is ready for users to stress test and challenge its resilience.
We're now entering a new phase: the Adversarial Testnet. This stage will test the resilience of the Aztec Testnet and its decentralization mechanisms.
The Adversarial Testnet introduces two key features: slashing, which penalizes validators for malicious or negligent behavior in Proof-of-Stake (PoS) networks, and a fully decentralized governance mechanism for protocol upgrades.
This phase will also simulate network attacks to test its ability to recover independently, ensuring it could continue to operate even if the core team and servers disappeared (see more on Vitalik’s “walkaway test” here). It also opens the validator set to more people using ZKPassport, a private identity verification app, to verify their identity online.
The Aztec Network testnet is decentralized, run by a permissionless network of sequencers.
The slashing upgrade tests one of the most fundamental mechanisms for removing inactive or malicious sequencers from the validator set, an essential step toward strengthening decentralization.
Similar to Ethereum, on the Aztec Network, any inactive or malicious sequencers will be slashed and removed from the validator set. Sequencers will be able to slash any validator that makes no attestations for an entire epoch or proposes an invalid block.
Three slashes will result in being removed from the validator set. Sequencers may rejoin the validator set at any time after getting slashed; they just need to rejoin the queue.
In addition to testing network resilience when validators go offline and evaluating the slashing mechanisms, the Adversarial Testnet will also assess the robustness of the network’s decentralized governance during protocol upgrades.
Adversarial Testnet introduces changes to Aztec Network’s governance system.
Sequencers now have an even more central role, as they are the sole actors permitted to deposit assets into the Governance contract.
After the upgrade is defined and the proposed contracts are deployed, sequencers will vote on and implement the upgrade independently, without any involvement from Aztec Labs and/or the Aztec Foundation.
Starting today, you can join the Adversarial Testnet to help battle-test Aztec’s decentralization and security. Anyone can compete in six categories for a chance to win exclusive Aztec swag, be featured on the Aztec X account, and earn a DappNode. The six challenge categories include:
Performance will be tracked using Dashtec, a community-built dashboard that pulls data from publicly available sources. Dashtec displays a weighted score of your validator performance, which may be used to evaluate challenges and award prizes.
The dashboard offers detailed insights into sequencer performance through a stunning UI, allowing users to see exactly who is in the current validator set and providing a block-by-block view of every action taken by sequencers.
To join the validator set and start tracking your performance, click here. Join us on Thursday, July 31, 2025, at 4 pm CET on Discord for a Town Hall to hear more about the challenges and prizes. Who knows, we might even drop some alpha.
To stay up-to-date on all things Noir and Aztec, make sure you’re following along on X.
Watch this: Alice sends Zcash. Bob receives USDC on Aztec. Nobody, not even the system facilitating it, knows who Alice or Bob are.
And Bob can now do something with that money. Privately.
This is the connection between private money and a private economy where that money can actually be used.
Zcash has already achieved something monumental: truly private money. It’s the store of value that Bitcoin promised (but made transparent). Like, digital gold that actually stays hidden.
But here's the thing about gold - you don't buy coffee with gold bars. You need an economy where that value can flow, work, and grow. Privately.
While other projects are trying to bolt privacy onto existing chains as an afterthought, Zcash is one of the oldest privacy projects in Web3. It's achieved what dozens of projects are still chasing: a truly private store of value.
This is critical infrastructure for freedom. The ability to store value privately is a fundamental right, a hedge against surveillance, and a given when using cash. We need a system that provides the same level of privacy guarantees as cash. Right now, there's over $1.1 billion sitting in Zcash's shielded pool, private wealth that's perfectly secure but essentially frozen.
Why frozen? Because the moment that shielded $ZEC tries to do anything beyond basic transfers: earn yield, get swapped for stablecoins, enter a liquidity pool, it must expose itself. The privacy in this format is destroyed.
This isn't Zcash's failure. They built exactly what they set out to build: the world's best private store of value. The failure is that the rest of crypto hasn't built where that value can actually work.
The Privacy Landscape Has an Imbalance
What happens when you want to do more than just send money? What happens when you want privacy after you transfer your money?
Private Digital Money (i.e., “Transfer Privacy,” largely solved by Zcash):
Private World Computer (i.e., After-the-Transfer Privacy):
Everyone else is competing to build better ways to hide money. Zcash has already built the private store of value, and Aztec has built the only way to use hidden money.
Here's the trillion-dollar question: What good is private money if you can't use it?
Right now, Zcash's shielded pool contains billions in value. This is money in high-security vaults. But unlike gold in vaults that can be collateralized, borrowed against, or deployed, this private value just sits there.
Every $ZEC holder faces two impossible choices:
Our demo breaks this false sense of choice. For the first time, shielded value can move to a place where it remains private AND becomes useful.
Here's how you can identify whether you’re dealing with a private world computer, or just private digital money:
Without a private world computer (every other privacy solution):
With a private world computer (only Aztec):
This is basic financial common sense. Your money should grow. It should work. It should be useful.
The technical reality is that this requires private smart contracts. Aztec is building the only way to interact privately with smart contracts. These smart contracts themselves can remain completely hidden. Your private money can finally do what money is supposed to do: work for you.
Our demo proves these two worlds can connect:
We built the bridge between storing privately and doing privately.
The technical innovation - "partial notes" - are like temporary lockboxes that self-destruct after one use. Money can be put privately into these lockboxes, and a key can be privately handed to someone to unlock it. No one knows who put the money in, where the key came from, or who uses the key. You can read more about how they work here. But what matters isn't the mechanism.
What matters is that Alice's Zcash can become Bob's working capital on Aztec without anyone knowing about either of them.
As a result, Bob receives USDC that he can:
You can't bolt privacy onto existing systems. You can't take Ethereum and make it private. You can't take a transparent smart contract platform and add privacy as a feature.
Aztec had to be built from the ground up as a private world computer because after-the-transfer privacy requires rethinking everything:
This is why there's only one name building fully private smart contracts. From the beginning, Aztec has been inspired by the work Zcash has done to create a private store of value. That’s what led to the vision for a private world computer.
Everyone else is iterating on the same transfer privacy problem. Aztec solves a fundamentally different problem.
Once you see it, you can't unsee it: Privacy without utility is only the first step.
Every privacy project will eventually need what Aztec built. Because their users will eventually ask: "Okay, my money is private... now what?"
This demo that connects Zcash to Aztec is the first connection between the old world (private transfers) and the new world (private everything else).
For Zcash Holders: Your shielded $ZEC can finally do something without being exposed.
For Developers: Stop trying to build better mattresses to hide money under. Start building useful applications on the only platform that keeps them private.
For the Industry: The privacy wars are over. There's transfer privacy (solved by Zcash) and after-the-transfer privacy (just Aztec).
This demo is live. The code is open source. The bridge between private money and useful private money exists.
But this is just the beginning. Every privacy project needs this bridge. Every private payment network needs somewhere for those payments to actually be used.
We're not competing with transfer privacy. We're continuing it.
Your private money yearns for the private economy.
Welcome to after-the-transfer privacy. Welcome to Aztec.
Privacy has emerged as a major driver for the crypto industry in 2025. We’ve seen the explosion of Zcash, the Ethereum Foundation’s refocusing of PSE, and the launch of Aztec’s testnet with over 24,000 validators powering the network. Many apps have also emerged to bring private transactions to Ethereum and Solana in various ways, and exciting technologies like ZKPassport that privately bring identity on-chain using Noir have become some of the most talked about developments for ushering in the next big movements to the space.
Underpinning all of these developments is the emerging consensus that without privacy, blockchains will struggle to gain real-world adoption.
Without privacy, institutions can’t bring assets on-chain in a compliant way or conduct complex swaps and trades without revealing their strategies. Without privacy, DeFi remains dominated and controlled by advanced traders who can see all upcoming transactions and manipulate the market. Without privacy, regular people will not want to move their lives on-chain for the entire world to see every detail about their every move.
While there's been lots of talk about privacy, few can define it. In this piece we’ll outline the three pillars of privacy and gives you a framework for evaluating the privacy claims of any project.
True privacy rests on three essential pillars: transaction privacy, identity privacy, and computational privacy. It is only when we have all three pillars that we see the emergence of a private world computer.
Transaction privacy means that both inputs and outputs are not viewable by anyone other than the intended participants. Inputs include any asset, value, message, or function calldata that is being sent. Outputs include any state changes or transaction effects, or any transaction metadata caused by the transaction. Transaction privacy is often primarily achieved using a UTXO model (like Zcash or Aztec’s private state tree). If a project has only the option for this pillar, it can be said to be confidential, but not private.
Identity privacy means that the identities of those involved are not viewable by anyone other than the intended participants. This includes addresses or accounts and any information about the identity of the participants, such as tx.origin, msg.sender, or linking one’s private account to public accounts. Identity privacy can be achieved in several ways, including client-side proof generation that keeps all user info on the users’ devices. If a project has only the option for this pillar, it can be said to be anonymous, but not private.
Computation privacy means that any activity that happens is not viewable by anyone other than the intended participants. This includes the contract code itself, function execution, contract address, and full callstack privacy. Additionally, any metadata generated by the transaction is able to be appropriately obfuscated (such as transaction effects, events are appropriately padded, inclusion block number are in appropriate sets). Callstack privacy includes which contracts you call, what functions in those contracts you’ve called, what the results of those functions were, any subsequent functions that will be called after, and what the inputs to the function were. A project must have the option for this pillar to do anything privately other than basic transactions.
Bitcoin ushered in a new paradigm of digital money. As a permissionless, peer-to-peer currency and store of value, it changed the way value could be sent around the world and who could participate. Ethereum expanded this vision to bring us the world computer, a decentralized, general-purpose blockchain with programmable smart contracts.
Given the limitations of running a transparent blockchain that exposes all user activity, accounts, and assets, it was clear that adding the option to preserve privacy would unlock many benefits (and more closely resemble real cash). But this was a very challenging problem. Zcash was one of the first to extend Bitcoin’s functionality with optional privacy, unlocking a new privacy-preserving UTXO model for transacting privately. As we’ll see below, many of the current privacy-focused projects are working on similar kinds of private digital money for Ethereum or other chains.
Now, Aztec is bringing us the final missing piece: a private world computer.
A private world computer is fully decentralized, programmable, and permissionless like Ethereum and has optional privacy at every level. In other words, Aztec is extending all the functionality of Ethereum with optional transaction, identity, and computational privacy. This is the only approach that enables fully compliant, decentralized applications to be built that preserve user privacy, a new design space that we see as ushering in the next Renaissance for the space.
Private digital money emerges when you have the first two privacy pillars covered - transactions and identity - but you don’t have the third - computation. Almost all projects today that claim some level of privacy are working on private digital money. This includes everything from privacy pools on Ethereum and L2s to newly emerging payment L1s like Tempo and Arc that are developing various degrees of transaction privacy
When it comes to digital money, privacy exists on a spectrum. If your identity is hidden but your transactions are visible, that's what we call anonymous. If your transactions are hidden but your identity is known, that's confidential. And when both your identity and transactions are protected, that's true privacy. Projects are working on many different approaches to implement this, from PSE to Payy using Noir, the zkDSL built to make it intuitive to build zk applications using familiar Rust-like syntax.
Private digital money is designed to make payments private, but any interaction with more complex smart contracts than a straightforward payment transaction is fully exposed.
What if we also want to build decentralized private apps using smart contracts (usually multiple that talk to each other)? For this, you need all three privacy pillars: transaction, identity, and compute.
If you have these three pillars covered and you have decentralization, you have built a private world computer. Without decentralization, you are vulnerable to censorship, privileged backdoors and inevitable centralized control that can compromise privacy guarantees.
What exactly is a private world computer? A private world computer extends all the functionality of Ethereum with optional privacy at every level, so developers can easily control which aspects they want public or private and users can selectively disclose information. With Aztec, developers can build apps with optional transaction, identity, and compute privacy on a fully decentralized network. Below, we’ll break down the main components of a private world computer.
A private world computer is powered by private smart contracts. Private smart contracts have fully optional privacy and also enable seamless public and private function interaction.
Private smart contracts simply extend the functionality of regular smart contracts with added privacy.
As a developer, you can easily designate which functions you want to keep private and which you want to make public. For example, a voting app might allow users to privately cast votes and publicly display the result. Private smart contracts can also interact privately with other smart contracts, without needing to make it public which contracts have interacted.
Transaction: Aztec supports the optionality for fully private inputs, including messages, state, and function calldata. Private state is updated via a private UTXO state tree.
Identity: Using client-side proofs and function execution, Aztec can optionally keep all user info private, including tx.origin and msg.sender for transactions.
Computation: The contract code itself, function execution, and call stack can all be kept private. This includes which contracts you call, what functions in those contracts you’ve called, what the results of those functions were, and what the inputs to the function were.
A decentralized network must be made up of a permissionless network of operators who run the network and decide on upgrades. Aztec is run by a decentralized network of node operators who propose and attest to transactions. Rollup proofs on Aztec are also run by a decentralized prover network that can permissionlessly submit proofs and participate in block rewards. Finally, the Aztec network is governed by the sequencers, who propose, signal, vote, and execute network upgrades.
A private world computer enables the creation of DeFi applications where accounts, transactions, order books, and swaps remain private. Users can protect their trading strategies and positions from public view, preventing front-running and maintaining competitive advantages. Additionally, users can bridge privately into cross-chain DeFi applications, allowing them to participate in DeFi across multiple blockchains while keeping their identity private despite being on an existing transparent blockchain.
This technology makes it possible to bring institutional trading activity on-chain while maintaining the privacy that traditional finance requires. Institutions can privately trade with other institutions globally, without having to touch public markets, enjoying the benefits of blockchain technology such as fast settlement and reduced counterparty risk, without exposing their trading intentions or volumes to the broader market.
Organizations can bring client accounts and assets on-chain while maintaining full compliance. This infrastructure protects on-chain asset trading and settlement strategies, ensuring that sophisticated financial operations remain private. A private world computer also supports private stablecoin issuance and redemption, allowing financial institutions to manage digital currency operations without revealing sensitive business information.
Users have granular control over their privacy settings, allowing them to fine-tune privacy levels for their on-chain identity according to their specific needs. The system enables selective disclosure of on-chain activity, meaning users can choose to reveal certain transactions or holdings to regulators, auditors, or business partners while keeping other information private, meeting compliance requirements.
The shift from transparent blockchains to privacy-preserving infrastructure is the foundation for bringing the next billion users on-chain. Whether you're a developer building the future of private DeFi, an institution exploring compliant on-chain solutions, or simply someone who believes privacy is a fundamental right, now is the time to get involved.
Follow Aztec on X to stay updated on the latest developments in private smart contracts and decentralized privacy technology. Ready to contribute to the network? Run a node and help power the private world computer.
The next Renaissance is here, and it’s being powered by the private world computer.
Special thanks to Santiago Palladino, Phil Windle, Alex Gherghisan, and Mitch Tracy for technical updates and review.
On September 17th, 2025, a new network upgrade was deployed, making Aztec more secure and flexible for home stakers. This upgrade, shipped with all the features needed for a fully decentralized network launch, includes a completely redesigned slashing system that allows inactive or malicious operators to be removed, and does not penalize home stakers for short outages.
With over 23,000 operators running validators across 6 continents (in a variety of conditions), it is critical not to penalize nodes that temporarily drop due to internet connectivity issues. This is because users of the network are also found across the globe, some of whom might have older phones. A significant effort was put into shipping a low-memory proving mode that allows older mobile devices to send transactions and use privacy-preserving apps.
The network was successfully deployed, and all active validators on the old testnet were added to the queue of the new testnet. This manual migration was only necessary because major upgrades to the governance contracts had gone in since the last testnet was deployed. The new testnet started producing blocks after the queue started to be “flushed,” moving validators into the rollup. Because the network is fully decentralized, the initial flush could have been called by anyone. The network produced ~2k blocks before an invalid block made it to the chain and temporarily stalled block production. Block production is now restored and the network is healthy. This post explains what caused the issue and provides an update on the current status of the network.
Note: if you are a network operator, you must upgrade to version 2.0.3 and restart your node to participate in the latest testnet. If you want to run a node, it’s easy to get started.
This upgrade was a team-wide effort that optimized performance and implemented all the mechanisms needed to launch Aztec as a fully decentralized network from day 1.
With these updates in place, we’re ready to test a feature-complete network.
As mentioned above, block production started when someone called the flush function and a minimum number of operators from the queue were let into the validator set.
Shortly thereafter, while testing the network, a member of the Aztec Labs team spun up a “bad” sequencer that produced an invalid block proposal. Specifically, one of the state trees in the proposal was tampered with.
The expectation was that this would be detected immediately and the block rejected. Instead, a bug was discovered in the validator code where the invalid block proposal wasn't checked thoroughly enough. In effect, the proposal got enough attestations, so it was posted to the rollup. Due to extra checks in the nodes, when the nodes pulled the invalid block from Ethereum, they detected the tampered tree and refused to sync it. This is a good outcome as it prevented the attack. Additionally, prover nodes refused to prove the epoch containing the invalid block. This allowed the rollup to prune the entire bad epoch away. After the prune, the invalid state was reset to the last known good block.
The prune revealed another, smaller bug, where, after a failed block sync, a prune does not get processed correctly, requiring a node restart to clear up. This led to a 90-minute outage from the moment the block proposal was posted until the testnet recovered. The time was equally split between waiting for pruning to happen and for the nodes to restart in order to process the prune.
Validators were correctly re-executing all transactions in the block proposals and verifying that the world state root matched the one in the block proposal, but they failed to check that intermediate tree roots, which are included in the proposal and posted to the rollup contract on L1, were also correct. The attack tweaked one of these intermediate roots while proposing a correct world state root, so it went unnoticed by the attestors.
As mentioned above, even though the block made it through the initial attestation and was posted to L1, the invalid block was caught by the validators, and the entire epoch was never proven as provers refused to generate a proof for the inconsistent state.
A fix was pushed that resolved this issue and ensured that invalid block proposals would be caught and rejected. A second fix was pushed that ensures inconsistent state is removed from the uncommitted cache of the world state.
Block production is currently running smoothly, and the network health has been restored.
Operators who had previously upgraded to version 2.0.3 will need to restart their nodes. Any operator who has not upgraded to 2.0.3 should do so immediately.
Slashing has also been functioning as expected. Below you can see the slashing signals for each round. A single signal can contain votes for multiple validators, but a validator's attester needs to receive 65 votes to be slashed.
Join us this Thursday, September 25, 2025, at 4 PM CET on the Discord Town Hall to hear more about the 2.0.3 upgrade. To stay up to date with the latest updates for network operators, join the Aztec Discord and follow Aztec on X.
Payy, a privacy-focused payment network, just rewrote its entire ZK architecture from Halo2 to Noir while keeping its network live, funds safe, and users happy.
Code that took months to write now takes weeks (with MVPs built in as little as 30 minutes). Payy’s codebase shrank from thousands of lines to 250, and now their entire engineering team can actually work on its privacy infra.
This is the story of how they transformed their ZK ecosystem from one bottlenecked by a single developer to a system their entire team can modify and maintain.
Eighteen months ago, Payy faced a deceptively simple requirement: build a privacy-preserving payment network that actually works on phones. That requires client-side proving.
"Anyone who tells you they can give you privacy without the proof being on the phone is lying to you," Calum Moore - Payy's Technical Lead - states bluntly.
To make a private, mobile network work, they needed:
To start, the team evaluated available ZK stacks through their zkbench framework:
STARKs (e.g., RISC Zero): Memory requirements made them a non-starter on mobile. Large proof sizes are unsuitable for mobile data transmission.
Circom with Groth16: Required trusted setup ceremonies for each circuit update. It had “abstracted a bit too early” and, as a result, is not high-level enough to develop comfortably, but not low-level enough for controls and optimizations, said Calum.
Halo2: Selected based on existing production deployments (ZCash, Scroll), small proof sizes, and an existing Ethereum verifier. As Calum admitted with the wisdom of hindsight: “Back a year and a half ago, there weren’t any other real options.”
Halo2 delivered on its promises: Payy successfully launched its network. But cracks started showing almost immediately.
First, they had to write their own chips from scratch. Then came the real fun: if statements.
"With Halo2, I'm building a chip, I'm passing this chip in... It's basically a container chip, so you'd set the value to zero or one depending on which way you want it to go. And, you'd zero out the previous value if you didn't want it to make a difference to the calculation," Calum explained, “when I’m writing in Noir, I just write ‘if’. "
With Halo2, writing an if statement (programming 101) required building custom chip infra.
Binary decomposition, another fundamental operation for rollups, meant more custom chips. The Halo2 implementation quickly grew to thousands of lines of incomprehensible code.
And only Calum could touch any of it.
The Bottleneck
"It became this black box that no one could touch, no one could reason about, no one could verify," he recalls. "Obviously, we had it audited, and we were confident in that. But any changes could only be done by me, could only be verified by me or an auditor."
In engineering terms, this is called a bus factor of one: if Calum got hit by a bus (or took a vacation to Argentina), Payy's entire proving system would be frozen. "Those circuits are open source," Calum notes wryly, "but who's gonna be able to read the Halo2 circuits? Nobody."
During a launch event in Argentina, "I was like, oh, I'll check out Noir again. See how it's going," Calum remembers. He'd been tracking Noir's progress for months, occasionally testing it out, waiting for it to be reliable.
"I wrote basically our entire client-side proof in about half an hour in Noir. And it probably took me - I don't know, three weeks to write that proof originally in Halo2."
Calum recreated Payy's client-side proof in Noir in 30 minutes. And when he tested the proving speed, without any optimization, they were seeing 2x speed improvements.
"I kind of internally… didn't want to tell my cofounder Sid that I'd already made my decision to move to Noir," Calum admits. "I hadn't broken it to him yet because it's hard to justify rewriting your proof system when you have a deployed network with a bunch of money already on the network and a bunch of users."
Convincing a team to rewrite the core of a live financial network takes some evidence. The technical evaluation of Noir revealed improvements across every metric:
Proof Generation Time: Sub-0.5 second proof generation on iPhones. "We're obsessive about performance," Calum notes (they’re confident they can push it even further).
Code Complexity: Their entire ZK implementation compressed from thousands of lines of Halo2 to just 250 lines of Noir code. "With rollups, the logic isn't complex—it's more about the preciseness of the logic," Calum explains.
Composability: In Halo2, proof aggregation required hardwiring specific verifiers for each proof type. Noir offers a general-purpose verifier that accepts any proof of consistent size.
"We can have 100 different proving systems, which are hyper-efficient for the kind of application that we're doing," Calum explains. "Have them all aggregated by the same aggregation proof, and reason about whatever needs to be."
Initially, the goal was to "completely mirror our Halo2 proofs": no new features. This conservative approach meant they could verify correctness while maintaining a live network.
The migration preserved Payy's production architecture:
"If you have your proofs in Noir, any person who understands even a little bit about logic or computers can go in and say, 'okay, I can kinda see what's happening here'," Calum notes.
The audit process completely transformed. With Halo2: "The auditors that are available to audit Halo2 are few and far between."
With Noir: "You could have an auditor that had no Noir experience do at least a 95% job."
Why? Most audit issues are logic errors, not ZK-specific bugs. When auditors can read your code, they find real problems instead of getting lost in implementation details.
Halo2: Binary decomposition
Payy’s previous 383 line implementation of binary decomposition can be viewed here (pkg/zk-circuits/src/chips/binary_decomposition.rs).
Payy’s previous binary decomposition implementation
Meanwhile, binary decomposition is handled in Noir with the following single line.
pub fn to_le_bits<let N: u32>(self: Self) -> [u1; N]
(Source)
With Noir's composable proof system, Payy can now build specialized provers for different operations, each optimized for its specific task.
"If statements are horrendous in SNARKs because you pay the cost of the if statement regardless of its run," Calum explains. But with Noir's approach, "you can split your application logic into separate proofs, and run whichever proof is for the specific application you're looking for."
Instead of one monolithic proof trying to handle every case, you can have specialized proofs, each perfect for its purpose.
"I fell a little bit in love with Halo2," Calum admits, "maybe it's Stockholm syndrome where you're like, you know, it's a love-hate relationship, and it's really hard. But at the same time, when you get a breakthrough with it, you're like, yes, I feel really good because I'm basically writing assembly-level ZK proofs."
“But now? I just write ‘if’.”
Technical Note: While "migrating from Halo2 to Noir" is shorthand that works for this article, technically Halo2 is an integrated proving system where circuits must be written directly in Rust using its constraint APIs, while Noir is a high-level language that compiles to an intermediate representation and can use various proving backends. Payy specifically moved from writing circuits in Halo2's low-level constraint system to writing them in Noir's high-level language, with Barretenberg (UltraHonk) as their proving backend.
Both tools ultimately enable developers to write circuits and generate proofs, but Noir's modular architecture separates circuit logic from the proving system - which is what made Payy's circuits so much more accessible to their entire team, and now allows them to swap out their proving system with minimal effort as proving systems improve.
Payy's code is open source and available for developers looking to learn from their implementation.
