# Kohaku

> Kohaku, an Ethereum Foundation privacy project with a wallet and SDK, enables private transactions, secure dApp interactions, and trust-minimized operations to ...

- Canonical URL: https://iq.wiki/wiki/kohaku
- Categories: Projects & Protocols
- Tags: Infrastructure
- Created: 2025-11-17T17:24:45.675Z
- Last updated: 2025-11-17T17:24:45.675Z
- Source: IQ.wiki — the world's largest blockchain and crypto encyclopedia (https://iq.wiki)

---

**Kohaku** is a privacy-focused research and development project initiated by the [Ethereum Foundation](https://iq.wiki/wiki/ethereum-foundation-ef) designed to enhance user security and confidentiality on the [Ethereum](https://iq.wiki/wiki/ethereum) network. It primarily consists of a set of primitives delivered through a software development kit (SDK) and a reference implementation wallet. The project's goal is to provide developers with the tools to build privacy features into their applications, rather than creating a mass-market consumer product. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE) [\[2\]](#cite-id-Tra3BC87XWipZBP8)​

## Overview

Kohaku is an end-to-end privacy solution for [Ethereum](https://iq.wiki/wiki/ethereum) that aims to make privacy a standard, integrated feature of the ecosystem. [\[3\]](#cite-id-aBJ7vQ8XkKyOSk4M) [\[4\]](#cite-id-XTvOIDHXxo351KOE) The project's philosophy is encapsulated in the slogan, "Privacy is normal. Privacy is for everyone." [\[2\]](#cite-id-Tra3BC87XWipZBP8) It addresses privacy vulnerabilities at every layer of user interaction, from local network activity to on-chain transactions, seeking to minimize the exposure of user metadata. [\[4\]](#cite-id-XTvOIDHXxo351KOE)​

The project delivers its technology in two main forms: the Kohaku SDK and the Kohaku reference wallet. The SDK is a modular toolkit with a plugin system, allowing wallet teams to select and integrate specific privacy and security features into their own products. The reference wallet, a browser extension forked from the [Ambire](https://iq.wiki/wiki/adex) wallet, serves as a demonstration vehicle for the SDK's capabilities and is targeted at developers and power users. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE) [\[4\]](#cite-id-XTvOIDHXxo351KOE)​

The initiative is part of a broader, renewed focus on privacy by the [Ethereum Foundation](https://iq.wiki/wiki/ethereum-foundation-ef), which aims to make confidentiality a "first-class property" of the blockchain. [\[3\]](#cite-id-aBJ7vQ8XkKyOSk4M) The project emphasizes a mainnet-first development approach, with plans to progressively support Layer 2 networks after the initial release. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)​

## History

The Kohaku project was officially announced on October 9, 2025, through coordinated posts by the [Ethereum Foundation](https://iq.wiki/wiki/ethereum-foundation-ef) and key project figures on the social media platform X. [\[2\]](#cite-id-Tra3BC87XWipZBP8) [\[5\]](#cite-id-jtz4PM8uplw5Whtw) Some outlets reported the official announcement date as October 10, 2025, although unofficial confirmations of the project had appeared in some channels as early as June 2025. [\[4\]](#cite-id-XTvOIDHXxo351KOE) The announcement was timed to occur shortly before [Devcon](https://iq.wiki/wiki/devcon), the annual [Ethereum](https://iq.wiki/wiki/ethereum) developer conference. [\[3\]](#cite-id-aBJ7vQ8XkKyOSk4M)​

The introduction of Kohaku followed the [Ethereum Foundation](https://iq.wiki/wiki/ethereum-foundation-ef)'s announcement on October 8, 2025, of the formation of the Privacy Cluster, a 47-member group of engineers, researchers, and cryptographers dedicated to integrating privacy across the [Ethereum](https://iq.wiki/wiki/ethereum) ecosystem. Kohaku is a key project within this broader strategic push. A public demonstration of the Kohaku wallet and its SDK was released for testing at the Devcon conference in Argentina in November 2025. [\[3\]](#cite-id-aBJ7vQ8XkKyOSk4M)​

## Name and Symbolism

The name "Kohaku" (琥珀) is the Japanese word for "Amber." This name was chosen because the project's reference wallet is a fork of the [Ambire](https://iq.wiki/wiki/adex) wallet. Coincidentally, "Kohaku" also refers to a well-known variety of red-and-white koi fish, and an illustration of a Kohaku koi was adopted as the project's logo. [\[5\]](#cite-id-jtz4PM8uplw5Whtw) [\[4\]](#cite-id-XTvOIDHXxo351KOE)

## Technology and Architecture

Kohaku is designed to provide end-to-end privacy, implementing features that protect user data from the local device up to the on-chain transaction. Its architecture relies on a combination of existing and novel cryptographic techniques. [\[3\]](#cite-id-aBJ7vQ8XkKyOSk4M) [\[4\]](#cite-id-XTvOIDHXxo351KOE)​

### Core Components

The Kohaku project consists of two primary deliverables:

* **Kohaku SDK:** A software development kit designed with a modular plugin system. This allows wallet development teams to adopt the entire suite of privacy features or to select specific modules (e.g., private sends, social recovery) that fit their needs.
* **Kohaku Reference Wallet:** A browser extension wallet, forked from [Ambire](https://iq.wiki/wiki/adex), that serves as a proof-of-concept and reference implementation for the SDK. It is targeted at power users and developers rather than the general public.

This two-part structure is intended to foster broad ecosystem adoption by providing flexible building blocks for existing wallet providers. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE) [\[4\]](#cite-id-XTvOIDHXxo351KOE)​

### On-Chain Privacy

For on-chain privacy, Kohaku integrates privacy pool protocols, with [Railgun](https://iq.wiki/wiki/railgun) being the first supported implementation. This allows users to obscure their transaction details, including the sender, receiver, and amount. The user experience for this feature typically involves three steps: [\[4\]](#cite-id-XTvOIDHXxo351KOE)​

1. **Shield:** A user deposits [ERC-20](https://iq.wiki/wiki/erc-20) tokens or wrapped Ether into the privacy protocol's smart contract. This initial "shield" transaction is public on the blockchain.
2. **Private Transactions:** Once assets are within the private pool, the user can privately transfer, swap, or interact with dApps. These transactions are verified on-chain using zero-knowledge proofs, which confirm the validity of the transaction without revealing its details. Observers of the blockchain can only see cryptographic updates to the pool's state.
3. **Unshield:** The user withdraws funds from the private pool to a public address. This "unshield" transaction is also public. To maintain privacy, users are advised to withdraw to a new, unused address. [\[4\]](#cite-id-XTvOIDHXxo351KOE)

### Network and Node Privacy

Kohaku implements several features to minimize metadata leakage at the network level, reducing reliance on trusted third parties like RPC (Remote Procedure Call) providers. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)​

* **RPC Independence:** The wallet integrates the Helios light client, which runs as a WebAssembly (WASM) package in the browser. This allows the wallet to verify blockchain data locally without trusting a third-party RPC provider, which could otherwise log a user's IP address and transaction data. An RPC fallback with a killswitch is included for redundancy. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE) [\[4\]](#cite-id-XTvOIDHXxo351KOE)
* **P2P Transaction Broadcasting:** Users have the option to broadcast transactions directly to the [Ethereum](https://iq.wiki/wiki/ethereum) peer-to-peer network. This practice bypasses centralized relayers and makes it more difficult to link a user's IP address to their on-chain activity. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)
* **IP Leakage Prevention:** The architecture includes mechanisms designed to prevent the unnecessary leakage of user IP addresses during interactions with the blockchain. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)

### dApp Interaction and State Reading

Kohaku introduces features to enhance privacy when interacting with decentralized applications (dApps) and reading blockchain state. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)​

* **Private State Reading:** To prevent RPC providers from knowing which parts of the blockchain state a user is accessing, Kohaku implements a minimal execution client in the browser for private `eth_call` functions. The initial implementation uses an oblivious server combining a Trusted Execution Environment (TEE) with Oblivious RAM (ORAM). The long-term goal is to replace this with purely cryptographic methods like Private Information Retrieval (PIR). [\[1\]](#cite-id-CFtdSvlyCwDZrwWE) [\[4\]](#cite-id-XTvOIDHXxo351KOE)
* **One Account Per dApp:** To prevent on-chain analysis firms from correlating a user's activity across different services, the wallet's default behavior is to prompt the user to create and use a new address for each new dApp they connect to. This compartmentalizes a user's on-chain footprint. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE) [\[4\]](#cite-id-XTvOIDHXxo351KOE)

### Account Security and Recovery

Beyond transactional privacy, Kohaku incorporates advanced security and recovery features. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)​

* **Social Recovery:** The project plans to offer standardized, intermediary-free social recovery options that leverage zero-knowledge proofs. This includes protocols like ZKemail, ZKpassport, and Anon Aadhaar, which allow users to recover accounts without publicly linking their real-world identities. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)
* **Post-Quantum Killswitch:** To mitigate the future threat of quantum computers breaking current cryptographic standards, Kohaku includes an optional feature to enable Post-Quantum (PQ) secure accounts. This uses optimized [Solidity](https://iq.wiki/wiki/solidity) verifiers for PQ signature schemes such as Falcon and Dilithium. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE) [\[4\]](#cite-id-XTvOIDHXxo351KOE)
* **Spending Policies:** The wallet will allow users to create account-level policies, such as setting spending limits for different signers associated with an account. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)

### Hardware and Wallet Integration

The Kohaku roadmap includes plans to foster a more open and interoperable hardware wallet ecosystem. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)​

* **Universal Hardware Wallet App:** A reference implementation for a universal "ethereum-app" for hardware wallets is planned to support advanced features and reduce vendor lock-in. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)
* **ZK Hardware Signer:** To ensure hardware wallet compatibility with ZK-based privacy protocols, the project includes support for elliptic curves like Jubjub and Bandersnatch, which are commonly used in ZK circuits. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)

## Future Developments and Research

The Kohaku roadmap outlines several ambitious long-term goals aimed at building a more deeply integrated private-by-default environment for [Ethereum](https://iq.wiki/wiki/ethereum) users. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)

* **Native Ethereum Browser:** The project contributors envision a native [Ethereum](https://iq.wiki/wiki/ethereum) browser as a logical next step. This would bring wallet security closer to the operating system level, enabling stronger security for dApp interfaces (e.g., those hosted on IPFS) and deeper P2P integration. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)
* **Local AI for Transaction Scoring:** Research is underway to develop on-device AI models that can assess transaction risk without leaking private user data to third-party analysis services. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)
* **Privacy-Preserving Account Abstraction:** A key research area is the development of privacy-preserving account abstraction, which would allow a single wallet to seamlessly control both public and private funds. This requires advances like client-side ZK-EVM or ZK-RISC-V provers. The team plans to work toward native account abstraction on [Ethereum](https://iq.wiki/wiki/ethereum) through 2026. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)
* **Private Data Recovery:** The project is exploring new social recovery schemes specifically for private data, such as wallet secrets or private ZK POAPs (Proof of Attendance Protocol NFTs). [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)

## Ecosystem and Collaboration

Kohaku is a collaborative effort led by the [Ethereum Foundation ](https://iq.wiki/wiki/ethereum-foundation-ef)and involves numerous teams and individuals from across the [Ethereum](https://iq.wiki/wiki/ethereum) ecosystem. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)​

### Key Figures

* **Nicolas Consigny (@ncsgy):** A developer at the Ethereum Foundation and one of the public faces of the Kohaku project. [\[5\]](#cite-id-jtz4PM8uplw5Whtw)
* [**Vitalik Buterin**](https://iq.wiki/wiki/vitalik-buterin)**:** Co-founder of [Ethereum](https://iq.wiki/wiki/ethereum), who was presented alongside Nicolas Consigny as a public face of Kohaku, signifying the project's importance. [\[5\]](#cite-id-jtz4PM8uplw5Whtw)
* **`@niard`:** The credited author of the technical roadmap for Kohaku, indicating a lead role in the project's technical architecture and development. [\[2\]](#cite-id-Tra3BC87XWipZBP8)

### Collaborating Organizations and Teams

* [Ethereum Foundation (EF)](https://iq.wiki/wiki/ethereum-foundation-ef)
* Privacy and Scaling Explorations (PSE)
* [Ambire](https://iq.wiki/wiki/adex)
* [Railgun](https://iq.wiki/wiki/railgun)
* Wonderland
* Helios (a16z)
* Oblivious Labs
* ZKnox
* Walletbeat (expected collaboration)

Many individual contributors are also involved in the project's development. [\[1\]](#cite-id-CFtdSvlyCwDZrwWE)​