Privacy · August 26, 2026

Understanding the privacy you are owed

We hand the details of our lives to software every day. We write our notes, record our meetings, and store our messages, and we trust that the companies holding all of it are careful with it. Most of us have no real way to check. The language these companies use to describe their protections is built to reassure, not to explain. This piece will give you enough of a working understanding to ask the right question, judge the answer, and expect more from the services you depend on.

Start with the word everyone uses: encrypted. Nearly every serious company will tell you your data is encrypted, and in a narrow sense that is usually true. What the word leaves out is the part that decides whether you are actually protected, which is who can remove the encryption. A lock keeps no one out if the company you are trusting holds a copy of the key.

Most services encrypt your data on their own servers, with keys they also hold. That protects you from a thief who steals a hard drive, and it protects your data while it moves across the network. It does nothing against the company itself, against an employee who decides to look, against an intruder who breaks in and finds the keys sitting beside the data, or against a government that arrives with a court order for everything in readable form. In each of those cases the encryption falls away, because the company being asked to unlock your data is the company that could always unlock it.

There is a different way to build these systems, and it is the way we build everything at Privt Labs. The encryption happens on your own device, before any of your data leaves it, and the key that performs it is created on your device too. That key comes from your passphrase. It is never sent to us, never stored on our servers, and never assembled anywhere but the hardware in your hand. What reaches us is sealed data we have no way to open, because the thing that opens it has never been ours.

You can understand this at whatever level you like, and it holds up at all three.

The plain version
Your notes are locked on your own device, with a key that only you hold.
A little more detail
Your passphrase becomes that key, on your device, and it never leaves.
The complete picture
Every note has its own key, wrapped by yours and sealed in your Mac's hardware.

The plain version

Your notes are locked on your own device before they are sent to us, with a key made from your passphrase that stays with you. We keep the sealed result and nothing else. Because we have never held the key, there is nothing we can hand over, sell, lose, or be made to reveal.

A little more detail

The method has a name: key derivation. Your passphrase is run through a purpose-built function on your device that turns it into a strong encryption key. Because that happens on your machine and your passphrase never leaves it, the key never leaves either. Everything is encrypted and decrypted on the devices you own. The whole system rests on a secret we are never in a position to learn.

The complete picture

Every note is encrypted with its own key, and that key is then encrypted with the key derived from your passphrase. We store the encrypted note next to the encrypted key, and neither is any use without the passphrase-derived key that only your device can produce. On a Mac, that top key can be held in the Secure Enclave, a dedicated chip that releases it only after your fingerprint, so it never exists in a form anyone could copy off the machine. The encryption uses established, well-studied methods, Argon2id to turn your passphrase into a key and XChaCha20-Poly1305 to protect your data, not homemade cryptography, because a company that writes its own is the last one you should trust with your privacy.

flowchart TD
  P["Your passphrase
known only to you"] --> K["Encryption key
derived on your device"]
  K --> N["Your notes, encrypted
before anything is sent"]
  N --> S["Our servers hold only
sealed data we cannot open"]
  K -. "never sent, never stored" .-> S
  classDef you fill:#eef4ff,stroke:#0066cc,color:#1d1d1f;
  classDef us fill:#f0f0f2,stroke:#c9c9cf,color:#1d1d1f;
  class P,K,N you;
  class S us;

This approach has a real cost, and that cost is the clearest proof it is genuine. If you lose both your passphrase and your recovery phrase, your data is gone for good, ours included. We hold no master key in reserve and run no process that can restore your access, because the design exists precisely to make sure no such thing is possible. A company that can always recover your account for you is telling you, plainly, that it can always reach your data.

The inability to rescue you is what protects you.

You do not need to be a cryptographer to protect yourself. You need one question, and the judgment to weigh the answer. Ask a service where your data is encrypted, and ask who holds the key. If it is encrypted on their servers and they hold the key, your privacy depends on their good behaviour and their good luck, and what you have is a promise. If it is encrypted on your device and you hold the key, your privacy is built into the system, and nothing they do or suffer can quietly take it away.

We build this way because we want it to become the ordinary standard, not the rare exception. The more people who know to ask the question, the harder it becomes for anyone to offer less.

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