Your Privacy

We can’t read your data. By design.

Most apps promise to protect your data. We went further: we built Avelia so that we are physically unable to access it. Not because of a policy — because of mathematics.

This approach is called zero-knowledge encryption, and it means that your most intimate data stays between you and your phone.

On your device
Period started today
On our servers
How it works

Think of it like a safe deposit box.

1

You hold the only key

When you create your account, your phone generates a unique encryption key. This key never leaves your device. We never see it, store it, or transmit it.

2

Your phone locks the box

Before any data leaves your phone — a journal entry, a cycle log, a symptom note — your phone encrypts it using your key. What reaches our servers is unreadable ciphertext: meaningless without your key.

3

We store sealed boxes

Our servers hold encrypted blobs. We can tell how many you have and when they were synced, but we cannot read what’s inside. Not your cycle data, not your journal, not your partner’s messages.

What this means for you

We can’t sell what we can’t read

There is no business model built on your data. We charge a fair price for the service, not for access to your life.

We can’t leak what we don’t have

If our servers are ever breached, attackers get encrypted noise. Your fertility data, your journal entries, your partner’s notes — all unreadable.

We can’t comply with what we can’t decrypt

Even if a court orders us to hand over your data, we can only provide ciphertext. Without your key, it is mathematically useless.

Technical summary

The facts, in one place.

For journalists, researchers, and security-conscious users who want the specifics:

Content encryption
AES-256-GCM (authenticated encryption)
Key derivation
Argon2id (OWASP-recommended, memory-hard)
Key storage
iOS Keychain / Android Keystore (hardware-backed)
Server storage
Opaque ciphertext only; no plaintext ever stored
Data residency
Germany; EU jurisdiction
Compliance
GDPR; not subject to US CLOUD Act
Court order capability
Can only produce ciphertext (mathematically useless)
Analytics
App: none. Website: self-hosted, cookie-less Matomo — no third-party SDKs
Questions & answers

Frequently asked questions

Can Avelia read my data?
No. Avelia uses zero-knowledge encryption. Your phone generates a unique Master Encryption Key on account creation that never leaves your device. All data is encrypted with AES-256-GCM before reaching our servers. We store only opaque ciphertext and have no technical means to decrypt it.
What is zero-knowledge encryption?
Zero-knowledge encryption is a cryptographic architecture where the service provider cannot decrypt user data, because the encryption keys are generated and stored solely on the user’s device. Avelia implements this using AES-256-GCM with Argon2id key derivation.
What happens if a court orders Avelia to hand over my data?
We can only provide encrypted blobs. Without your Master Encryption Key — which we never see or store — the data is mathematically useless. This is a structural guarantee, not a policy promise.
What if Avelia’s servers are hacked?
Attackers would only find encrypted ciphertext. Your fertility data, journal entries, and partner notes would remain unreadable without your device’s key. The breach would expose metadata (timestamps, sync volumes) but no actual content.
Can Avelia sell or share my data with advertisers?
No. There is no business model built on your data — we cannot sell what we cannot read. Avelia is funded by subscriptions, not advertising, and uses no third-party analytics or tracking SDKs.
More about how we protect you
Data Security → Safe Mode →