> For the complete documentation index, see [llms.txt](https://docs.railgun.org/wiki/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.railgun.org/wiki/learn/privacy-system/privacy-overview.md).

# Privacy Overview

How RAILGUN's ZK proofs and Broadcasters keep transactions private without any custodian.

With this knowledge of [ZK proofs and zk-SNARKs](https://docs.railgun.org/wiki/learn/privacy-system/zero-knowledge-cryptography), we can see how RAILGUN maintains privacy. Users can prove they can spend tokens without needing to share what those tokens are and how much they have of it. Broadcasters and the privacy set then enhance the data confidentiality for senders and recipients of interactions such that no identifiable information is compromised at any stage in the process.

To use an old-world analogy, RAILGUN users are writers of letters, ZK proofs fact check the contents of the letters, RAILGUN smart contracts are a sealed envelope, and Broadcasters are mailmen. All an outside observer can see is that a letter has been posted, but they would have no visibility as to what is in the letter or who has sent it.

RAILGUN is **not** a safe, vault, or deposit box. Those imply a party holding your funds somewhere. RAILGUN is non-custodial, and no one, including RAILGUN contributors, ever holds user funds. 

<figure><img src="https://4189133001-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MgpI5FGDnzf3cR6tzx7%2Fuploads%2Ft7FMVUqCN90NdQTskJuf%2Frailgun_flowchart_-02.png?alt=media&#x26;token=521dfa7b-0746-4d5c-a9ef-b32ef1d690b0" alt=""><figcaption></figcaption></figure>