By George Curta · Last updated 2026-07-24
Zero-Knowledge Security
Your password NEVER leaves your device. We use smart cryptography to verify you without ever seeing your password - the most secure way to protect your account.
What is Zero-Knowledge?
When you log in to most websites, your password travels over the internet to the server. Even though it's encrypted during travel, the server still sees your password.
With Zero-Knowledge, your password stays on YOUR device. Instead, we use smart math to prove you know the password without ever sending it.
Regular Login
You show your ID card to get into a building
Zero-Knowledge Login
You prove you know a secret handshake, but never reveal what it is
Why Use Zero-Knowledge?
Password Never Sent
Even if hackers watched your internet connection, they cannot steal your password because it never travels over the network.
We Cannot See It
Not even anonym.legal staff can see your password. Your credentials remain completely private.
Better Protection
If our servers were ever compromised, your password would still be safe. We only store mathematical proofs, not passwords.
Five-Phrase Recovery
You get special recovery words to regain access if you forget your password. No calling support - you control your account.
How It Works
Zero-Knowledge authentication in 4 simple steps
Create Password
You create a password on your device
Generate Secret Key
Your device creates a secret key from your password using special math
Send Proof
Only a mathematical proof is sent to us - never your password
Verify
We verify the proof - we can confirm it's you without seeing your password
It's like having a lock where you keep the only key, and we just check if your key works.
Your Five Recovery Phrases
When you enable Zero-Knowledge, you receive five separate recovery phrases of 24 words each. Any three of the five are enough to recover your account — you do not need all five, and no single phrase works on its own.
What are these phrases for?
- Recover your account if you forget your password
- Regain access if you lose your device
- Log in on a new computer
DO
- Write each phrase down on its own sheet of paper, numbered 1 to 5
- Store them in FIVE DIFFERENT places — this is the whole point, not extra caution
- Keep at least three of those places somewhere you could still reach after a fire, flood or move
DO NOT
- Keep all five in the same place — one accident then loses your account, and one burglary hands it over
- Throw the other four away after saving one — a single phrase can never recover anything
- Take a photo of them
- Save them on your computer
- Send them by email or text
- Share them with anyone
Why five phrases, any three?
- You can lose up to two and still get back in
- Anyone who finds only one or two learns nothing at all
- But anyone who gathers three can recover your account — so keep them apart
- 24 words per phrase is easy to write down correctly and to read back
Important
Without at least three of your five recovery phrases, we CANNOT help you get back into your account. This is by design — Zero-Knowledge means we do not have your password or your keys, so there is nothing for us to look up.
Works Everywhere
Zero-Knowledge protection across all anonym.legal platforms
Technical Details
For the security-conscious
Argon2id Key Derivation
Memory-hard algorithm that makes password guessing extremely slow, even with specialized hardware.
XChaCha20-Poly1305
The same authenticated encryption used by security experts worldwide for maximum protection.
No Password Storage
We never store your password in any form - encrypted, hashed, or otherwise.
Constant-Time Verification
Security checks take the same time regardless of input, preventing timing attacks.
Frequently Asked Questions
Can anonym.legal staff see my password?
No. That's the whole point of Zero-Knowledge! Your password is processed on your device. We only receive a mathematical proof, never the actual password.
What if anonym.legal gets hacked?
Your password is still safe! Hackers would only find mathematical proofs, not passwords. Without your actual password, they cannot access your account.
Is Zero-Knowledge harder to use?
No! You won't notice any difference when logging in. The only extra step is saving your 24-word recovery phrase when you first set up your account.
Can I turn off Zero-Knowledge?
Zero-Knowledge is enabled by default for your protection. We recommend keeping it on for the best security.
What happens if I change my password?
When you change your password, your device creates new secret keys and you receive a new 24-word recovery phrase. Your old recovery phrase stops working, so save your new phrase immediately!
After the LastPass breach, how can I verify a vendor uses true zero-knowledge encryption?
anonym.legal uses Argon2id key derivation (64MB memory, 3 iterations) running entirely in the browser — the server never receives your password or encryption key. AES-256-GCM encryption happens before data leaves your device. Even a full server breach yields only encrypted blobs without the keys to decrypt them.
Technical Appendix
Cryptographic parameters and protocol details for security auditors and developers.
Cryptographic Parameters
| Component | Algorithm | Parameters |
|---|---|---|
| Password Hashing | Argon2id | Memory: 64 MB, Iterations: 3, Parallelism: 1, Salt: 16 bytes, Output: 32 bytes |
| Symmetric Encryption | XChaCha20-Poly1305 | AEAD, 256-bit key, 24-byte nonce (random per operation) |
| Key Derivation | HKDF-SHA256 | Master Key → Auth Key + Encryption Key (domain separation) |
| Recovery Phrase | BIP39 | 256-bit entropy, 24 words, 2048-word wordlist |
| Random Number Generation | CSPRNG | crypto.getRandomValues (browser), libsodium.randombytes_buf (native) |
Key Derivation Chain
Sent to server for verification
Never leaves device
Protocol Flow
Registration
- 1Client generates random salt (16 bytes)
- 2Client derives Master Key via Argon2id(password, salt)
- 3Client derives Auth Key and Encryption Key via HKDF
- 4Client sends Auth Key + salt to server (password never sent)
Login
- 1Client requests salt from server (by email)
- 2Client re-derives Master Key via Argon2id(password, salt)
- 3Client sends Auth Key; server verifies with timing-safe comparison
- 4Server issues JWT session token; Encryption Key stays on device
Cross-Platform Compatibility
| Platform | Crypto Library | Argon2id Parallelism |
|---|---|---|
| Web App (Browser) | libsodium.js (WebAssembly) | 1 |
| Desktop App (Tauri) | rust-argon2 + libsodium.js | 1 |
| Office Add-in | libsodium.js (WebAssembly) | 1 |
Parallelism is set to 1 across all platforms to ensure cross-platform compatibility. A key derived on any platform works on all others.
From the Blog
View all articlesSelf-Hosted PII Fails Compliance Audits
spaCy 3.4.4 produces different NER results than spaCy 3.5.1. Financial services firm discovers 3% of documents were differently anonymized in staging vs.
Presidio Misses 220+ GDPR Entities
Presidio ships with ~40 default entity recognizers focused on US identifiers. European organizations need IBAN, Codice Fiscale.
Configuration Drift: A Hidden GDPR Risk
Analyst A replaces names with pseudonyms. Analyst B blacks them out. Your GDPR audit finds both in the same dataset. Configuration drift — where team.
Protect Your Account Now
Create an account with Zero-Knowledge security. Your password stays yours - always.
Limitations / Important note
- Zero-knowledge protection depends on you safeguarding your keys; if you lose them, encrypted data cannot be recovered.
- Client-side guarantees apply to supported workflows only — check the documentation for scope.
- This page is informational and is not legal advice.
About this page
We update this page when our platform or the law changes.
Read our founder note for how we work.
Each change shows up in the timestamp at the top.
Related reading
We follow these rules
- GDPR (EU 2016/679).
- ISO/IEC 27001:2022, held by our hosting provider.
- NIS2 (EU 2022/2555).
- HIPAA safe harbor under 45 CFR § 164.514(b)(2).
Our promise
We do not sell your data.
We do not train models on your text.
We store your files in Germany.
You can delete your account at any time.
You own your work.
Where we run
Our company HQ is in Saarbrücken, Germany. Our servers run in Hetzner's Falkenstein datacenter.
Hetzner holds ISO 27001 certification.
All data stays in the EU.
Backups run every day.
Need help?
Email support@anonym.legal.
We reply within one business day.
How we test
Automated checks run on every release.
Each surface gets its own sweep script and report.
Human reviewers spot-check the output each week.
We test detection against sample documents before each release.
A failing unit or integration run stops the release.
What we never do
- We never sell your information to third parties.
- We never train models on what you upload.
- We never keep your work after you delete it.
- We never share keys with any outside firm.
- We never run ads inside the product.
Plans in plain words
We sell credits, not seats.
One credit covers one short job.
Long jobs use a few credits each.
Paid plans can buy top-up credits.
Credits reset at the end of each cycle.
Read the plans page for current rates.
Who built this
A small team of engineers and lawyers built this.
We ship from Europe and work in the open.
Our founder note spells out why we started.
Where to start
- Open the web app and try a sample file.
- Learn how credits get counted.
- See current plans and limits.
- Meet the team behind the product.
How the parts fit
A browser add-on cleans text inside Chrome.
A Word plug-in handles drafts in Office.
A small desktop tool works on whole folders.
An agent protocol link feeds large models safely.
All four share one core engine and one rule set.
Words from our team
We started this work after a lunch about cookies.
One friend kept getting odd ads on her phone.
We asked why a court file leaked through a draft.
We sketched the first build on a napkin that week.
By month three we had a tiny demo for a friend.
She used it on her first case the next day.
Common questions we hear
Can the tool read scanned PDFs? Yes, with OCR.
Does it work on long files? Yes, in small chunks.
Can I roll my own rule set? Yes, save it as a preset.
Does it run offline? The desktop build runs offline.
Do you keep my files? No, the cloud build wipes after each run.
Will it learn from my work? No, we never train on inputs.
A short tour of the workflow
Upload a file or paste a snippet of prose.
Pick the entities you want gone from the draft.
Choose a method: replace, mask, hash, encrypt, or redact.
Press run and watch the side panel show each hit.
Skim the result and tweak any rule that misfired.
Save the cleaned file or send it to a teammate.