Iron Fish

Market position

Iron Fish presents itself as a privacy layer usable by assets from other chains rather than a single-asset privacy coin, and claims to be the first to support multi-asset private transactions. During phase 2 of its incentivized testnet it reported surpassing 39 million fully shielded transactions, which it characterizes as making it one of the largest processors of zero-knowledge proofs. Its founder was recognized on the Forbes 30 Under 30 Finance 2022 list.

Privacy is applied to every transaction by default while remaining selectively disclosable through wallet viewing keys, and privacy can be extended to arbitrary imported assets rather than only a native coin. The project also pairs privacy with compliance controls: inbound and outbound bridge transfers pass sanctions screening and threat detection through ChainPort, and flagged addresses can have bridged funds frozen.

Technology

The protocol applies zero-knowledge proofs (zk-SNARKs) to every transaction so that sender, recipient and amount are encrypted, with a proof accompanying each transfer. Wallets use a three-key model (private, public, viewing) enabling optional disclosure of transaction history. Consensus is proof of work with approximately 60-second block times (525,600 blocks per Iron Fish 'year'). The implementation spans TypeScript (SDK and CLI) and Rust (core transaction, chain and ZKP libraries, plus NodeJS addon and WASM builds). The core protocol implementation was audited by Inversed Tech, with the audit finalized on 1 June 2023.

Go-to-market

Distribution is community- and developer-led: open-source repositories on GitHub, downloadable node and wallet software (desktop node app, CLI, OreoWallet browser wallet, mobile wallet, Ledger app), documentation, a Discord community, a newsletter, and Foundation-run grants and governance. An incentivized testnet with an associated airdrop was used to bootstrap participation ahead of mainnet.

Cryptocurrency holders seeking confidential transfers of assets across chains, miners and node operators, and developers building on or integrating with the network. The community is described as spanning miners, engineers and privacy advocates across multiple countries.

Geography

Headquartered in San Francisco, California, with a distributed, global community of miners, node operators and contributors.

History

Iron Fish raised a $27-28 million round led by a16z announced in November 2021. Its incentivized testnet ran from December 2021 to February 2023 across three phases, and mainnet launched on 20 April 2023, the same date the Iron Fish Foundation was established. A security audit of the core protocol by Inversed Tech was finalized on 1 June 2023. In March 2025, Coinbase's Base acquired the Iron Fish development team to build privacy primitives for Base, with the blockchain and IRON token excluded from the deal and Elena Nadolinski remaining on the foundation board. Subsequent milestones announced on the company blog include a mobile wallet in March 2025 and SuiFish, extending Iron Fish privacy to Sui, in October 2025. An April 2026 post announced that the Iron Fish Foundation is moving to maintenance mode.

Risks & controversies

The March 2025 acquisition of the development team by Coinbase's Base separated core contributors from the chain and token, which were excluded from the transaction, and the Foundation announced a move to maintenance mode in April 2026. The network's compliance approach — freezing bridged funds from addresses flagged as malicious by ChainPort's screening — introduces intervention capability at the bridge layer. Token distribution concentrates a large share of the genesis block with insiders, with 37.4% to the core team and roughly 29.5% across preseed, seed, Series A and advisor allocations, subject to a 12-month lockup and subsequent monthly unlocks.