Puffer Finance has laid out the security architecture behind its ETH staking product, saying security is not an added feature but the foundation of the protocol itself. The company said that since going live in 2024, Puffer has recorded more than $1 billion in peak total value locked and processed over $1 billion in ETH redemptions without a pause, withdrawal limits, or a depeg.
In the article, Puffer said those milestones reflect more than growth. They are also meant to show how its infrastructure performs when real users and large amounts of capital rely on it. The team argued that security remains one of DeFi’s biggest challenges, with risks extending beyond smart contract bugs to stolen keys, deployment misconfigurations, and failures in off-chain infrastructure. For that reason, it said, security has to cover the full system, including code development and deployment, protocol permissions, validator operations, threat monitoring, and withdrawals.
Every release goes through multiple layers of review
Puffer said every contract release comes with a full testing suite. Before human auditors review the code, AI audit agents continuously inspect it. According to the company, those agents are updated as new vulnerabilities are disclosed across the industry and improve alongside new frontier model releases.
The protocol also uses what it described as a “linear third-party audit” process. One top-tier audit firm reviews the code first. After fixes are made, a second independent audit firm reviews the already audited and remediated version before deployment. Puffer said that structure is designed to reduce the chance that an issue missed by one audit team reaches mainnet.
The article said Puffer’s core contracts have been audited in sequence by Trail of Bits, Nethermind, and Creed. It also said the protocol has undergone audits by BlockSec, SlowMist, and Quantstamp, and has taken part in an open Immunefi competition. Even small upgrades, Puffer said, must be audited, with no exceptions.
Puffer added one more step that it said many protocols skip: a deployment audit. The company argued that even a flawless contract can become a vulnerability if deployment parameters are wrong. After deployment, each role, permission, and parameter is checked again and then published for anyone to inspect.
Permission design is built to avoid single points of control
Puffer said it uses OpenZeppelin’s Access Manager to apply fine-grained controls to function calls. Its model assigns responsibilities across three separate multisigs.
- Operations handles day-to-day protocol management. Any upgrade it proposes must pass through a 7-day timelock that is hard-coded into the contracts as a minimum requirement, which the company said cannot be shortened by anyone.
- Security Council is a multisig made up of Ethereum community leaders. Its role is to block malicious activity during that 7-day window, including governance attacks or signer compromises, and to act immediately in time-sensitive protection scenarios.
- Pauser can do only one thing: pause the protocol. Any authorized signer, whether a person or a machine, can trigger that action at once but cannot do anything else through that role.
Puffer said this setup makes automated defense possible. Real-time monitoring from BlockSec Phalcon is wired directly into the pause authority, so the protocol can be halted immediately if an attack is detected. The 7-day timelock also gives users time to move assets if they disagree with a proposed change, according to the article.
The design assumes every critical key can be compromised
Puffer said its security model starts from the assumption that any key can fail. In an environment where custody keys, GitHub access, and cloud credentials can be compromised even without direct operator fault, the team said redundancy is non-negotiable. Every important key connected to user funds is protected by multisig, according to the company.
Off-chain, Puffer said it goes a step further by using trusted execution environments, or TEEs. The article described Puffer as the first to bring TEE attestation on-chain. Under that setup, hardware cryptographically proves which code is actually running. Puffer said that means even if a developer machine were fully compromised, an attacker could not tamper with off-chain components or redirect validators. Validator withdrawal credentials always point to the Puffer Vault, enforced by hardware rather than personal trust, the team said.
The article also pointed to a previous case in the industry in which a major node operator suffered an infrastructure attack, had to exit all validators it was running, and contributed to a large backlog in Ethereum’s exit queue. Puffer said that kind of failure has been designed out of its own architecture.
Node operators absorb losses before stakers do
Puffer said every node operator on the platform must post a 2 ETH bond, held in pufETH, before running validators. That bond acts as first-loss capital. If a validator misbehaves or is slashed, the operator’s own collateral is burned first to absorb losses before staker principal is affected.
The team added that the bond is not sized for an ordinary bad day. It is calibrated for worst-case conditions. The article said Ethereum slashing penalties grow as the amount of ETH slashed across the network in the same time window increases, meaning highly correlated failures face harsher penalties.
According to Puffer, the bond is calibrated so that staker principal remains fully protected even if as much as 2% of all staked ETH on Ethereum is slashed in the same window. Using a conservative ETH price of $2,000, the company said that would imply more than $1.6 billion of staked assets being slashed in a single network-wide event while pufETH would still avoid a depeg. In that scenario, the pufETH bonds of slashed operators would be burned to absorb the damage and preserve the exchange rate for stakers, the article said.
Withdrawal design has already handled more than $1 billion in redemptions
Puffer said that in the weeks after withdrawals were opened, the protocol processed more than $1 billion in ETH redemptions without pauses, withdrawal restrictions, or a depeg. The company linked that performance to a Vault-based architecture with two exit routes.
Users can pay a small fee to withdraw instantly using Vault liquidity, or they can choose a standard withdrawal path with no fee. Puffer said the system was designed not only for deposits but also for exits, and that it has already been tested at scale.
Security extends to the user-facing website
Puffer said its security work does not end at the smart contract layer. The protocol uses real-time alerts to flag malicious npm packages before they reach the front end. The article framed the website itself as the final mile of user security.
Summing up its approach, Puffer said the stack combines repeated audits, hardware-enforced trust, automated defenses, and a withdrawal record tested under real conditions, with all of it verifiable on-chain.
Building for the next phase
The article closed by saying DeFi will keep changing and so will the risks around it. Puffer said it plans to keep learning from the broader ecosystem, strengthening defenses, and adapting as new threats appear. The team added that it will continue investing in security research, independent reviews, automated monitoring, and transparent infrastructure, while keeping those practices visible to users rather than asking them to rely on promises alone.
Puffer said it is building for the long term and that protecting the people who choose to build, stake, and participate with the protocol will remain central to every decision.
The original article also included a disclaimer stating that markets carry risk and the content does not constitute investment advice. Users should decide for themselves whether any opinion, view, or conclusion fits their own situation and bear responsibility for any investment decisions made on that basis.