Ethereum co-founder Vitalik Buterin has presented Kohaku, a next-generation privacy framework designed to bring default private transactions to Ethereum while maintaining optional transparency for regulatory compliance. The Ethereum Foundation plans to officially unveil Kohaku at the upcoming Devcon, marking one of the most significant privacy-focused upgrades in Ethereum’s recent history.
What Kohaku Is Designed to Solve
Kohaku aims to strike a balance between user privacy and regulatory requirements, an issue that has challenged Ethereum for years. Instead of broadcasting sensitive wallet information publicly, Kohaku restructures how transactions are detected and linked on-chain.
How Kohaku Works
At the center of Kohaku is a system of ephemeral stealth addresses:
- •When Alice sends funds to Bob, she doesn’t transfer ETH to Bob’s public wallet.
- •Instead, she generates a one-time stealth address, derived from Bob’s public key.
- •Only Bob’s wallet can detect, recognize, and spend from that hidden address.
- •The transaction appears on-chain, but it cannot be tied to Bob’s identity without his consent.
This approach prevents public linking of transfers, dramatically improving privacy without requiring mixers, tumblers, or separate privacy chains.
Built for Compliance, Not Obscurity
Unlike privacy systems that obscure all information, Kohaku includes an explicit compliance mechanism:
- •Users can choose to reveal the connection between a stealth address and their main wallet when required, such as for audits, tax reporting, or institutional onboarding.
- •By default, this link is not visible on-chain.
This dual-mode system allows privacy for everyday usage while remaining compatible with regulated environments like exchanges, custodians, and enterprise Ethereum solutions.
Tools and Integration
The Ethereum Foundation plans to launch Kohaku as:
- •A browser extension for everyday users
- •A developer SDK for wallets, dApps, and infrastructure teams
Kohaku is being constructed on top of proven privacy technologies such as Privacy Pools and RAILGUN, ensuring cryptographic robustness and compatibility with Ethereum’s existing ecosystem.
Part of Ethereum’s New Privacy Cluster
Kohaku is the first major public output of the Ethereum Foundation’s newly formed Privacy Cluster, a group of 47 cryptography, engineering, and UX experts focused on embedding privacy across the entire Ethereum stack, from base-layer standards to application tooling.
This signals a broader strategic shift: Ethereum wants privacy not as an optional add-on, but as a foundational principle of the network.
Kohaku’s reveal at Devcon is expected to set the stage for a wave of privacy-centric Ethereum improvements going into 2026.