Hey friends!
I’m a big fan of Bitcoin and crypto in general. However, we have to admit it has several problems, and probably the main one is: all transactions on all blockchains are completely public. Every transfer, every balance, every interaction is totally transparent. If I go buy some sausage at a store in the crypto city of the future, the whole city can easily find out about it.
Smart folks have been trying to fix this for over ten years, but:
Monero, Zcash and similar — they only protect their own token within their own chain. Want private BTC or ETH? Sorry, that’s not what we do.
Tornado Cash — a mixer model with fixed amounts. Small anonymity set, one asset at a time, fragmented privacy.
Namada — the most advanced project today, a unified shielded pool for all assets. Great cryptography! But stuck on Cosmos/IBC. Access to BTC, ETH, SOL only through bridges. And bridges… well, you know the problem with those.
Spinner, Whirltrace on ICP — also the Tornado Cash model. Fixed amounts, one asset, small pool.
The problem isn’t cryptography, we’ve long known how to hide transactions (zk-SNARKs, STARKs, Ring Signatures, Stealth Addresses, and many other methods, for every taste). The problem is that there was no infrastructure allowing a single protocol to natively work with ALL major chains without bridges or intermediaries.
But now, thanks to DFINITY, ICP, and Chain Fusion, this possibility has finally arrived.
Architecture overview:
Four layers:
UX layer — the user sees a familiar wallet: shieldBTC, shieldETH, shieldUSDC. These are their decrypted notes via a spending key. Only they can see them.
MASP canister — the heart of the system. A single Merkle tree on ICP containing encrypted notes for all assets. ZK proofs are generated in the user’s browser (PLONK + Poseidon2) and verified by the canister in ~10ms. vetKeys issue encryption keys via threshold BLS — no single node sees the full key.
Chain Fusion layer — the bridge between MASP and the outside world. On shield: accepts native BTC/ETH/SOL, mints ck-tokens. On unshield: burns ck-tokens, threshold-signs a native transaction (ECDSA for BTC/ETH, EdDSA for SOL) and sends it to the target chain.
External chains — Bitcoin, Ethereum, Solana, any EVM chain. The user works with native assets on input and output. Inside — full privacy.
Why only ICP can do this:
Chain Fusion — native threshold signing (ECDSA, Schnorr, EdDSA) for BTC, ETH, SOL, DOGE. No bridges, no intermediaries. A canister directly signs transactions on other chains.
WASM canisters — on-chain ZK-SNARK verification in ~10ms. Cloaking Layer by zCloak has already proven this works.
vetKeys — decentralized key management. No single node sees the full key. Perfect for encrypting data in the pool.
Reverse gas — transfers within the pool are free for the user.
500 GiB storage per canister — more than enough for a Merkle tree.
I’ll admit, I only recently took a deep dive into ICP, and it genuinely blew me away, I had no idea infrastructure like this already existed. But I think many of you clearly know more than I do.
I’d love to hear your thoughts, criticism, suggestions on this, and so on.
Thanks for your attention!