Kohaku: Vitalik’s New Privacy Framework Could Redraw the Map for Ethereum and Starknet

For years, Ethereum’s superpower has also been its greatest weakness: everything is visible. Every payment, every NFT mint, every DeFi position sits on a public ledger that anyone can query. That transparency has enabled an explosion of tooling, but it has also turned everyday users into open books for chain analysts, trading firms and, increasingly, regulators.

Vitalik Buterin’s newly unveiled Kohaku framework is an attempt to rewrite that bargain. Rather than bolt on yet another privacy coin or sidechain, Kohaku sketches a way to make privacy a default behaviour at the wallet layer while keeping Ethereum’s base protocol largely intact. If it works, the most visible outcome for end users could be simple: the days of using a single, easily traceable address for everything would quietly end.

And if privacy really becomes native to Ethereum’s everyday UX, the repercussions go far beyond protecting retail users’ portfolios from curious neighbours. It changes how institutions approach on-chain activity, how regulators think about surveillance, and how competing ecosystems like Starknet position themselves in the race to host serious capital – including Bitcoin whales hunting for yield without handing their entire balance sheet to every block explorer.

1. What Kohaku actually is – and what it is not

Kohaku is best understood as a framework and a set of conventions, not as a new blockchain or token. In line with Vitalik’s earlier privacy roadmaps, it focuses on three layers that can be upgraded without tearing out Ethereum’s consensus engine:

• Wallet behaviour – how addresses are generated, how balances are displayed, and how transactions are composed.
• Application patterns – how dApps integrate with privacy pools, mixers or zk-based schemes, and how they treat user identifiers.
• Supporting infrastructure – relayers, RPC endpoints and off-chain services that can add network-level privacy without breaking verifiability.

Kohaku does not promise absolute anonymity. Ethereum remains a transparent ledger. Instead, the goal is to break the easy link between a user’s real-world identity and their entire on-chain life. Today, that link is often just one reused address away. Kohaku’s central idea is to make that kind of reuse obsolete.

2. From one public address to many ephemeral personas

In practical terms, Kohaku encourages wallets to stop treating “your Ethereum address” as a single, permanent identity. Instead, wallets generate and manage many sub-addresses behind the scenes. For different applications – or even each individual transaction – the wallet can spin up a fresh address, fund it from a shielded balance, execute the action and then retire it.

For the user, the experience is meant to feel familiar: you still see a unified balance in your wallet dashboard, you still click “Send” or “Swap” as usual. Under the hood, however, several things change:

• Per-transaction addresses. Each payment, trade or DeFi interaction can use a new one-time address. Observers can verify that the transaction is valid, but linking it back to your main identity becomes much harder.
• Shielded internal accounting. The wallet keeps a private record of which ephemeral addresses belong to you, aggregating their balances into a single view that only you see. On-chain, your activity looks like many independent actors rather than one monolithic account.
• Application-scoped identities. You might effectively have one persona for a DEX, another for an NFT marketplace and a third for a gaming protocol – all managed from the same wallet, but with no easy public link between them.

This is conceptually similar to using different email addresses for banking, social media and newsletters – except here it is automated and cryptographically enforced. You don’t need to click “create new wallet” each time; Kohaku’s rules tell the software when and how to rotate addresses.

3. MetaMask and the mainstreaming of privacy UX

The most powerful aspect of Kohaku is not any particular cryptographic trick but its UX-first philosophy. Vitalik’s privacy writings have long argued that expecting users to juggle separate “privacy wallets” is a dead end. Most people will always default to whatever is easiest. To make privacy real, it has to live where the users already are.

That is why early commentary has focused on potential integration with wallets like MetaMask. A Kohaku-aware MetaMask would not require users to learn zero-knowledge proofs or read long explainer threads. Instead, you might see options like:

• “Send from private balance (recommended)”
• “Use one-time address for this dApp”
• “Refresh identity for this protocol after X days”

Behind those simple toggles, the wallet could tap into privacy pools, zk-rollup bridges or trusted execution environments that protect RPC traffic. The Kohaku framework’s job is to make sure these components talk to each other in a consistent, auditable way so that the user’s privacy doesn’t depend on obscure settings.

If MetaMask and other leading wallets adopt even a subset of Kohaku’s guidelines, the impact on on-chain data will be dramatic. Chain-analysis dashboards that currently map one address to “one user” will be dealing instead with a swarm of ephemeral identities. Behavioural clustering will still be possible, but it will require more work and more assumptions.

4. Privacy is no longer a passing trend – it’s a survival requirement

It is tempting to dismiss privacy pushes as cyclical hype. Every few years, a new wave of privacy coins, mixers or stealth-address schemes captures attention, only to run into regulatory pushback or fizzle out due to poor UX.

What’s different this time is the macro context:

• Institutional capital is here. Pension funds, corporates and high-net-worth individuals are increasingly interacting with Ethereum directly or via L2s. For them, full transparency is a double-edged sword: compliance teams love auditability, but treasurers do not love broadcasting every portfolio move to competitors.
• Regulatory data demands are rising. Travel rules, tax-reporting regimes and real-time monitoring tools are all expanding. Some of this is unavoidable, but users are pushing back against systems where a single leaked address reveals their entire financial history.
• AI-driven surveillance is getting cheaper. Even if no human cares about your address today, machine learning models can comb through historical data indefinitely. What feels harmless now could become sensitive later when correlations are discovered.

In that environment, privacy is not a niche feature – it is closer to encryption for web traffic. Twenty years ago, HTTPS was optional; today, a serious web service without it would be laughed out of the room. Kohaku is part of Ethereum’s attempt to make a similar journey: move from “everything is public forever” to “the system is transparent where it needs to be and private where it can be.”

5. Starknet’s strategic position in a privacy-first world

Whenever Ethereum shifts priorities, L2 ecosystems feel the tremors first. Starknet, built by StarkWare, has long positioned itself at the intersection of scalability and privacy via zk-STARK rollups. Unlike traditional zk-SNARK systems that power many privacy coins, STARKs aim to provide post-quantum security and transparent setup, making them attractive for long-term infrastructure.

There are several reasons why a Kohaku-style privacy wave on Ethereum could be especially bullish for Starknet:

• Deep cryptographic pedigree. StarkWare’s founders, including Eli Ben-Sasson and Alessandro Chiesa, were among the researchers who helped design the proving systems used in early privacy projects like Zcash. They are not the commercial founders of Zcash, but their work underpins much of the field. That gives Starknet unique credibility when serious capital looks for privacy-preserving L2s.
• Native zk architecture. Starknet was born as a zk-rollup, not upgraded into one later. Its design assumes frequent proof generation and verification as core operations. That makes it a natural platform for building advanced privacy applications that need to prove complex statements about user behaviour without revealing raw data.
• Room for more opinionated privacy defaults. While Ethereum L1 must balance many stakeholders and regulatory pressures, L2s like Starknet can experiment with more aggressive privacy models – for example, account abstractions that use stealth addresses or batched transactions as defaults.

In practice, we may see a division of labour: Kohaku improving baseline privacy for everyday Ethereum users, while Starknet and other zk-L2s become the venues for more sophisticated, high-volume private activity – from institutionally sized DeFi trades to complex DAO governance.

6. The Bitcoin angle: discreet yield for the whales

A less obvious but potent consequence of Ethereum-native privacy is its effect on Bitcoin capital. Over the last cycle, wrapped BTC and bridging solutions allowed Bitcoin holders to tap into Ethereum and L2 DeFi yields. The trade-off was visibility: once BTC entered an ERC-20 wrapper or cross-chain bridge, its movements were open to anyone willing to follow the trail.

Starknet’s ongoing work to integrate Bitcoin more deeply into its ecosystem – whether via trust-minimised bridges, rollup-aware vaults or new representations of BTC – becomes more compelling in a Kohaku world. Imagine the following path becoming routine for a large holder:

1. Lock BTC in a smart-contract vault or bridge that emits a Starknet-native representation of that BTC.
2. Use Kohaku-style wallet patterns and Starknet’s zk-infrastructure to route that BTC liquidity through lending pools, perpetual DEXs or yield strategies without advertising every move.
3. Periodically exit back to base-layer BTC with a clean, verifiable record for auditors, but without handing competitors a full play-by-play of interim strategies.

This is not about hiding from regulators; serious players will still need audit trails. It is about commercial privacy: the ability to deploy capital and experiment with strategies without every address-scraper immediately front-running or reverse-engineering them.

If Starknet can offer that blend of programmable privacy for BTC while plugging into Ethereum’s broader liquidity and developer base, it could evolve into a kind of privacy-enabled cross-asset hub – especially attractive in a world where Bitcoin ETFs have normalised BTC on institutional balance sheets but not solved the problem of on-chain information leakage.

7. The trade-offs and open questions

No serious privacy upgrade comes without trade-offs. Kohaku is no exception, and a professional analysis has to weigh both sides.

7.1. Compliance and policy friction

More powerful privacy tools inevitably attract scrutiny from regulators concerned about money laundering, sanctions and tax evasion. The design challenge for Kohaku and privacy-heavy L2s will be to separate user-level confidentiality from system-level accountability.

Expect to see experiments with:

• Opt-in or jurisdiction-specific disclosure controls (for example, giving users the ability to generate viewing keys for auditors).
• Compliance-aware privacy pools that block known bad actors while still offering anonymity sets for legitimate users.
• Standards for how wallets and dApps surface risk disclosures when interacting with privacy-enhanced features.

7.2. UX complexity hidden under the hood

Kohaku’s promise rests on the idea that complex address-rotation and shielding logic can be abstracted away from users. In practice, building wallets that manage dozens or hundreds of sub-addresses safely is non-trivial. Edge cases – partially signed transactions, hardware wallet flows, cross-chain bridges – can reveal more information than intended if not handled carefully.

There is also the issue of user education. Even in a Kohaku world, some actions will remain inherently public (for example, participating in governance under a known identity). Users will need to understand which behaviours are covered by privacy defaults and which are not.

7.3. Data analysis and market transparency

Finally, greater privacy changes how analysts, market makers and risk engines operate. Many of today’s risk dashboards rely on address-level heuristics to track whales, token concentration or protocol health. With pervasive address rotation, those tools will need to lean more on protocol-level metrics – flows in and out of pools, aggregate volume, volatility – rather than wallet-level profiling.

That shift is healthy from a privacy standpoint but will require a rebuild of much of the existing analytics ecosystem. Some business models based purely on deanonymisation may simply not survive.

8. How investors and builders should read the Kohaku moment

For investors, Kohaku is a reminder that Ethereum’s roadmap is not just about throughput and fees. It is about defining what “public” actually means in a world where every transaction is theoretically inspectable forever. Assets and protocols that align with that direction – wallets that adopt privacy defaults, L2s that complement Kohaku rather than compete with it, infrastructure that respects user confidentiality – stand to benefit.

For builders, the message is even clearer: design for privacy by default. That does not mean hiding everything. It means thinking from day one about which pieces of data actually need to be public and which can be abstracted, shielded or aggregated. Protocols that build on Kohaku principles early will be in a better position when mainstream users and institutions start demanding privacy as a baseline, not a nice-to-have.

Conclusion: Kohaku as a bridge from transparent past to selective-disclosure future

Kohaku will not flip a switch overnight. Ethereum will still look and feel public for quite some time, and the ecosystem will need to experiment, iterate and occasionally backtrack as it learns where the right privacy–transparency balance lies.

But as a signal, the framework matters. It tells us that Ethereum’s leadership expects privacy to be a defining battleground for the next decade: for users’ safety, for institutional adoption and for competition with other chains. In that contest, Starknet and other zk-heavy L2s are not side stories; they are laboratories where the most ambitious ideas about private yet verifiable computation will be tested.

If Kohaku succeeds, the future Ethereum stack may look very different from today’s: wallets that routinely rotate addresses and manage shielded balances, DeFi protocols that reveal aggregate liquidity without exposing every participant, and cross-chain hubs where assets like Bitcoin can seek yield without dragging their entire ownership history into the open.

For now, what matters is that the conversation has moved. Privacy on Ethereum is no longer a fringe topic or a short-lived trend; it is being written into the network’s long-term design. Kohaku is the latest chapter in that story – and quite possibly the one that finally brings privacy out of specialist circles and into the default settings of the crypto world’s biggest smart-contract platform.

Disclaimer: This article is for informational and educational purposes only and does not constitute investment, trading, legal or tax advice. Some of the future integrations and use cases discussed, such as wallet support for Kohaku or Starknet’s Bitcoin connectivity, are speculative and may not materialise as described. Always conduct your own research and consult qualified professionals before making financial decisions.