> For the complete documentation index, see [llms.txt](https://ciphera.gitbook.io/zerosats-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ciphera.gitbook.io/zerosats-docs/welcome-to-zerosats/faqs.md).

# FAQs

<details>

<summary>What makes Zerosats transactions private?</summary>

Zerosats uses client-side zero-knowledge proofs to prove, and verify, the validity of a transaction, but not reveal the contents of said transaction to the broader network.

</details>

<details>

<summary>Is Zerosats a bitcoin l2?</summary>

No. Zerosats is an independent blockchain. It can uses bridges to bring bitcoin-backed tokens onto the network.

</details>

<details>

<summary>What "version" of bitcoin is on Zerosats?</summary>

Zerosats uses wcBTC. cBTC tokens, bitcoin tokens on Citrea, are locked in a non-custodial smart contract on Citrea. The tokens locked into this contract are those that back Zerosats BTC notes. BTC backing cBTC is secured by Clementine, an implementation of BitVM secured by a 10 member federation.&#x20;

</details>

<details>

<summary>Can the Zerosats operator steal user funds?</summary>

No. Zerosats' bridge is a smart contract that processes deposits and withdrawals based on receiving a valid "validity proof". A validity proof is a cryptographic proof that proves the state of the Zerosats to its corresponding bridge contract on Citrea. Users trust the cryptography behind the Zerosats bridge contract **and** Citrea's Clementine bridge to ensure funds are secure.

</details>

<details>

<summary>Is Zerosats self-custodial (or non-custodial)?</summary>

**While Zerosats operators themselves do not custody user funds**, users trust the integrity of Citrea's Clementine bridge (managed by a federation of 10 operators) and the Citrea security council (a 3-of-5 multisig) to not steal user funds. They also trust the soundness of Zerosats smart contracts. Zerosats contracts have not undergone audits.

</details>

<details>

<summary>Is Zerosats decentralized?</summary>

No. The Zerosats network is run by a single operator. Please note that this operator does not custody user funds and cannot steal user funds. However, if the operator goes offline, users can submit their own exit out of the system.

</details>

<details>

<summary>What happens if the Zerosats operator goes offline?</summary>

In the unlikely event that the Zerosats operator goes offline for more than 7 days, users can exit the system by calling the bridge contract to process a withdrawal. A full guide on how to do this will be released soon.

</details>

<details>

<summary>How should I use Zerosats?</summary>

Zerosats is a live example on how users can do bitcoin payments with zero-knowledge proofs. Users should only use a small amount of funds to experiment with the network. We have currently disabled deposits and are onboarding users onto the network with our own funds.

</details>

<details>

<summary>What is Zerosats' connection to bitcoin?</summary>

It does not have a direct connection to bitcoin. It brings bitcoin tokens onto the network through a bridge on a bitcoin rollup.

</details>

<details>

<summary>How is Zerosats different than Chaumian Ecash?</summary>

The Zerosats network operator does not custody user funds. The operator is solely responsible for ordering and validating transactions. This unlike Chaumian Ecash where the single custodian, or federation, is additionally the operator of the mint.

</details>

<details>

<summary>Is Zerosats integrated with the Lightning Network?</summary>

Yes. For deposits, we support an integration with Atomiq exchange. For payments, we developed our own HTLC circuit and run a Phoenixd lightning gateway.

</details>

<details>

<summary>Why did Zerosats launch on top of Citrea instead bitcoin directly?</summary>

We do not want to manage a federation that is responsible for custodying L1 UTXOs. Citrea's execution environment enables us to launch non-custodial contracts that secure funds backing notes on Zerosats. For product iteration, we feel the trust assumptions and tradeoffs are adequate for small payments.

</details>

<details>

<summary>Are the other implementations of bitcoin privacy protocols, using ZK, self-custodial (or non-custodial)?</summary>

No.

</details>

<details>

<summary>I don't think the Zerosats tradeoffs are worth it. </summary>

That's fine. Don't use it.

</details>

<details>

<summary>Is Zerosats open-source?</summary>

Yes. All of our work is free and open-source under the MIT license.

</details>