zkCoins / zkCoins is on Nostr

Private Bitcoin transactions on L1.

First implementation of the Shielded CSV protocol — zero-knowledge proofs hide amount, sender and receiver, while a 64-byte nullifier settles on Bitcoin.

No altcoin. No soft fork. No coordinator. Open source ⚡

Last Notes

2026-07-13 17:26:00 GMT

Bitcoin blockspace is public and scarce
The zkCoins target design amortises one publisher batch across many private, client-validated spends. The current specification defines a constant 231-byte inscription payload per batch. Including the funding commit and reveal transaction, it estimates about 318 vBytes per batch — about 3.2 vBytes per spend when a batch contains 100 spends.
Hidden from chain-only observers: individual amounts, assets, senders, receivers, the transaction graph and even the batch record count. Still visible: the protocol marker and version, publisher key, accumulator roots, bundle locator, block anchor and signature.
Privacy through zero-knowledge proofs and client-side validation, anchored to Bitcoin without a consensus change.
https://image.nostr.build/0b8d2977d4797c09e6292dd477454d08cd3773a353cd3cc9534e464014efc6ca.png

2026-07-11 14:30:20 GMT

Bitcoin payments are public by default.
zkCoins is designed as a private client-side-validation payment layer anchored to Bitcoin — without changing Bitcoin consensus.
Amounts, assets, sender, receiver and the transaction graph stay off-chain. Zero-knowledge proofs establish validity, while a permissionless publisher anchors a whole batch of spends with a constant 231-byte inscription payload.
Bitcoin still sees protocol commitments and publisher metadata, but no individual payment amount or parties.
No separate chain. No native protocol token. No soft fork.
The specification describes the target design. We are building and testing the implementation in public: https://zkcoins.com
https://image.nostr.build/698aa1d8db1e3c31448dbc19d0a0f2a65c529c6707e6f7a782cbcab13879e3fc.png

2026-07-11 14:00:44 GMT

Your Bitcoin has no privacy.
Every Bitcoin payment you have ever made is still sitting on a public ledger, readable by anyone, forever. Your salary, your savings, the rent you paid last month. All of it, in the open...
Today we are showing what we built to fix that, in public.
zkCoins makes Bitcoin private
Value on Bitcoin, sent and received privately, while amounts, sender, receiver and history all stay off-chain — proven with zero-knowledge and anchored to Bitcoin as one constant 231-byte inscription per batch. Nothing legible ever touches the chain.
The full loop — create, mint, send, receive — already runs end to end on a public signet.
No new coin. No sidechain. No soft fork. Just Bitcoin, finally private.
https://image.nostr.build/636a382aa1886c8686a236317ce0e8c89ba03b2f6de8a51a4ac60f280f527530.jpg

2026-07-10 13:30:24 GMT

Your Bitcoin is now private!
Every Bitcoin payment you have ever made is still sitting on a public ledger, readable by anyone, forever. Your salary, your savings, the rent you paid last month. All of it, in the open...
Today we are showing what we built to fix that, in public.
zkCoins makes Bitcoin private
Real BTC, sent and received, while amounts, sender, receiver and history all stay off-chain, proven with zero-knowledge and anchored to Bitcoin as one constant 231-byte inscription per batch. Nothing legible ever touches the chain.
No new coin! No sidechain! No soft fork! Just Bitcoin, finally private!
https://image.nostr.build/76e626ad552ed7affd2cee5e2aac5c733d1c0280d9b2f39c4776dd37ab540f81.jpg

2026-07-09 13:29:58 GMT

Bitcoin is the most transparent money ever made!
Every payment you have ever sent still sits on a public ledger, readable by anyone, forever. Your salary. Your savings.
That was never the promise!
zkCoins fixes it!
Real Bitcoin, sent and received, while the chain shows nothing legible. Amounts, sender, receiver and history stay off-chain, proven with zero-knowledge and anchored to Bitcoin as one constant 231-byte inscription per batch.
Let us be blunt about what this is not
- Not a sidechain
- Not a soft fork waiting on consensus
- Not a mixer
It is stronger cryptography applied to the Bitcoin you already hold. It works on Bitcoin as it exists today — no consensus change, no new opcodes.
Your keys never leave your device!
https://image.nostr.build/70f7efc324c82a574af0084dbd1af52117b7819bb0c64fe20c088721c45b04da.jpg

2026-07-09 13:29:38 GMT

2026-07-09 13:21:44 GMT

2026-07-09 13:00:56 GMT

Bitcoin is the most transparent money ever made!
Every payment you have ever sent still sits on a public ledger — the amount, the sender, the receiver, the entire history — readable by anyone, forever. Your salary. Your savings. The coffee you bought this morning.
That was never the promise!
zkCoins fixes it!
Real Bitcoin, sent and received, while the chain shows nothing legible. Amounts, sender, receiver and history stay off-chain, proven with zero-knowledge and anchored to Bitcoin as one constant 231-byte inscription per batch — roughly 3.2 vBytes per spend, and none of it reveals a thing.
Let us be blunt about what this is not
- Not a new coin
- Not a sidechain
- Not a soft fork waiting on consensus that may never come
- Not a mixer with an anonymity set to pick apart
- Not a rollup with a sequencer to trust
It is stronger cryptography applied to the Bitcoin you already hold. It works on Bitcoin as it exists today — no consensus change, no new opcodes. Your keys never leave your device!
https://image.nostr.build/70f7efc324c82a574af0084dbd1af52117b7819bb0c64fe20c088721c45b04da.jpg

2026-07-07 20:33:09 GMT

🚀 [TEST] zkCoins — private Bitcoin on L1
No altcoin. No soft fork. No coordinator. Just Bitcoin, made private. ⚡
Wallet: https://zkcoins.app
https://image.nostr.build/7c536d00929899116512f7af9af3b73d419a7ae8d80936dc5ba1a476d3d6f7a1.jpg

2026-07-07 18:44:34 GMT

🚀 [TEST] zkCoins is live on Bitcoin mainnet
Private Bitcoin payments — no altcoin, no soft fork, no coordinator. Your amounts, sender and receiver stay completely private. ⚡
560 bytes per transaction → just 64 bytes on-chain.
Read the paper: https://eprint.iacr.org/2025/068
Open the wallet: https://zkcoins.app
https://image.nostr.build/17a6d01c424926a8ecb490aa49a21052fe087269e97c58c79e08ca7ea6178e74.png