Frequently asked questions

Bitcoin ZKA Lab is an open-source research lab that ships Apache 2.0 libraries implementing zero-knowledge architecture (ZKA) for Bitcoin applications. ZKA means the SaaS operator cannot read user data — amounts, contacts, memos, or identifiers — even under subpoena, breach, or insider threat.

Zero-knowledge architecture is a software design pattern where data is encrypted client-side before it reaches the server. The operator stores opaque ciphertext and runs queries through blind proxies. Unlike a privacy policy, ZKA is a structural guarantee — the operator cannot read user data because they never had the keys.

E2EE typically protects messages between two endpoints (user to user). ZKA extends the same principle to single-user applications and SaaS multi-tenancy: the user is one endpoint, and the application logic running in their browser is the other. The server is untrusted infrastructure in both cases.

The lab builds zk-bitcoin-accounting (zero-knowledge double-entry bookkeeping), zk-personal-finance (client-side personal finance), and a Bitcoin data aggregator (Bitcoin data aggregation with encrypted credentials, planned). zk-support (end-to-end encrypted support ticketing) is planned. All use Apache 2.0.

Apache License 2.0 in perpetuity. There is no commercial restriction, no equity, no patent grab, and no contributor IP assignment beyond the standard Apache CLA terms. Content on the website is CC BY 4.0.

Most libraries are alpha as of 2026. zk-bitcoin-accounting has an external cryptographic audit scoped with Cure53. zk-support is planned. Production deployment requires reading the per-library threat model and consulting the audit status.

NGOs and human rights groups protecting sensitive financial records, and journalists protecting financial information. Also relevant for Bitcoin-native applications (accounting, personal finance, aggregation, support) that want privacy by architecture rather than by policy.

Yes. Apache 2.0 permits commercial use, modification, and redistribution without royalties. There are no usage caps, no per-seat fees, and no copyleft obligations on downstream applications.

Bitcoin ZKA Lab aligns with Bitcoin-native and freedom-tech communication norms — primarily Nostr, GitHub, email, and RSS. No Twitter/X account is maintained by design.

Email hello@bitcoin-zka.org. PGP key is published at bitcoin-zka.org/pgp.txt. The lab acknowledges disclosures within 48 hours and publishes post-mortems.

No. The site runs no analytics, no cookies, and no third-party trackers. Fonts are served from a privacy-respecting host (Bunny Fonts). Server logs are rotated every 30 days.

A cloud accounting service can read financial records if it stores them in readable form. zk-bitcoin-accounting encrypts amounts, contacts, memos, and account names client-side. Its operator stores ciphertext instead of readable business data. Compare encryption boundaries, threat models, maturity, and audit status before deployment.

Conventional aggregation connects financial accounts; privacy depends on the provider’s credential and data handling. The Bitcoin data aggregator targets Bitcoin exchanges, wallets, and Lightning nodes with client-side credential encryption. Compare adapter coverage, credential handling, and operator visibility rather than assuming equivalent capabilities.

Accounting: https://github.com/Bitcoin-ZKA/zka-accounting. Personal finance: https://github.com/Bitcoin-ZKA/zka-personal-finance. The Bitcoin data aggregator and zk-support are planned and have no repository links yet.