Resources

Security at Marknote

Your notes are some of the most personal things you write. This page explains, in plain language, how we keep them safe: what happens on your computer, what happens when you sync, how we look after your account, and how we build and test Marknote itself.

Local first

Your notes are files on your computer. Nothing is sent anywhere unless you turn on sync.

Encrypted end to end

Synced notes are locked on your device first. We cannot read them.

Passkeys

Sign in with your fingerprint, face or a security key instead of a password.

Built with care

Reviewed changes, automated tests and security scanning on every change.

Your notes start, and can stay, on your computer

Marknote works with ordinary Markdown files in a folder you choose. Out of the box nothing you write is sent anywhere: no account is needed, and there is no copy of your notes on our servers unless you turn on Marknote Sync. The app comes from the Microsoft Store, which checks and signs every update before it reaches you.

Themes and plugins are built to be safe to try. A theme is a list of colours with no code in it, and the app checks every value before using it. A plugin runs in a sealed-off sandbox with no access to the internet or to the files on your computer.

When you sync, your notes are encrypted before they leave your device

Marknote Sync uses end-to-end encryption. Your notes are locked on your own computer, with a key made from a passphrase that only you know, before anything is sent. Our service stores and passes along that locked copy, but it has no way to unlock it, and neither do we. That also means nobody who got into our servers could read your notes.

  • Strong, well-studied encryption. Notes are encrypted with AES-256-GCM, the same standard trusted by banks and governments, which also detects if anything has been tampered with.
  • A key only you can make. Your passphrase is turned into a key with Argon2id, a method designed to make guessing passphrases slow and expensive.
  • A way back in, that is also yours. A recovery key lets you regain access if you forget your passphrase. We never see either, so if both are lost we cannot recover your notes. That is the price of nobody else being able to read them.

Looking after your account

  • Passkeys. You can sign in with a passkey, using your fingerprint, face, PIN or a security key instead of a password. Passkeys follow the FIDO2 standard and cannot be phished or reused on a fake site.
  • Passwords, if you prefer them. We never store your password itself, only a protected scrambled form made with Argon2id. New passwords are checked against lists of passwords exposed in other companies' breaches, in a way that never sends your password anywhere.
  • The app never sees your password. Signing in to the app opens your browser, so a passkey or security key works and your password stays with our account pages.
  • Protection against automated attacks. Sign-up is protected against bots, repeated attempts are slowed down, and an email address has to be confirmed before an account is used.

How the service is run

  • Encrypted connections everywhere. Every connection to Marknote uses HTTPS, and browsers are told never to connect any other way.
  • Hosted on Microsoft Azure, in data centres in Europe, with the physical and network security that comes with it.
  • Keys and secrets are kept out of our code, and each part of the service can reach only what it needs.
  • Web pages are locked down with strict security headers that stop other sites framing them and stop unexpected scripts from running.
  • Watched around the clock. Automated monitoring alerts us to errors, unusual activity and outages. You can see how the service is doing on our status page.
  • Email you can trust. Mail from marknote.md is signed so your inbox can check it really came from us, which makes it much harder for anyone to send convincing fake Marknote emails.

What our team can and cannot see

Our staff can see what they need to help you, such as the email address on an account, and nothing that is yours to keep private. They cannot read your notes, because the service cannot. Staff tools are protected by physical security keys, and every action taken in them is recorded in a log that cannot be changed or deleted. Support tickets are the exception to encryption: staff read what you write so they can answer, as our privacy policy explains.

How we build and test Marknote

  • Every change is checked and tested before it is released.
  • Automated tests run on every change, including tests for the encryption, the sign-in flows and what the service refuses to do.
  • The code is scanned with automated security and quality analysis, and we carry out our own security reviews of each part of Marknote.
  • Dependencies are watched. The libraries we build on are monitored for known vulnerabilities and kept up to date.
  • Builds are locked down, using exact, known versions of the tools that produce them.
  • Changes reach test environments first, before they are released to everyone.

The standards we follow

We build on public, widely reviewed standards rather than inventing our own:

Standard What it means for you
AES-256-GCM The encryption that locks your synced notes, and spots any tampering.
Argon2id How your passphrase and password are protected, designed to make guessing very slow.
FIDO2 and WebAuthn The passkey standard: sign-ins that cannot be phished or reused elsewhere.
OAuth 2.0 with PKCE How the app signs in through your browser without ever handling your password.
NIST password guidance Checking new passwords against known breaches, rather than forcing regular changes.
HTTPS (TLS) with HSTS Every connection is encrypted, and browsers are told never to use an unencrypted one.
OWASP Top 10 The common web security risks we design and review against.
SPF, DKIM and DMARC Mail from marknote.md can be verified, so fake Marknote emails are easier to spot.
RFC 9116 (security.txt) A standard, public place to find out how to report a security issue.

Found a security problem?

We welcome reports from anyone who finds a weakness in Marknote. Email security@marknote.md and tell us what you found and how to see it. Please give us a reasonable chance to fix it before telling anyone else, and do not access, change or delete anyone else's data while you look. Our contact details are also published in the standard place for security researchers, /.well-known/security.txt.

Your data, in detail

Security is about keeping your data safe; privacy is about what we collect at all. Our privacy policy covers what Marknote stores, why, and how to delete it.

Rejoining the server...

Rejoin failed... trying again in seconds.

Failed to rejoin.
Please retry or reload the page.

The session has been paused by the server.

Failed to resume the session.
Please retry or reload the page.