Privacy notice

Effective 6 October 2026 · mineracks pty ltd, Brisbane, Australia

1. Who this covers

This notice covers the website anytwokeys.com and the Any Two Keys software for Mac, iPhone, iPad and Android, all published by mineracks pty ltd ("mineracks", "we"). It is written to meet the Australian Privacy Act 1988 and the Australian Privacy Principles.

2. The website

The site is static pages. It sets no cookies, runs no analytics or tracking scripts, and has no accounts or forms. It is delivered through Cloudflare, which as our content delivery and security provider processes the internet address and request details of each visit to serve the page and to block abuse. Cloudflare's own handling of that data is described in its privacy policy. Fonts are loaded from Google Fonts, which sees a request for the font files from your browser.

3. The app

Any Two Keys runs on a Mac, an iPhone, an iPad or an Android phone. On every one of them it keeps what it knows on that device, encrypted, and talks to your YubiKeys through the device's own smart-card interface: a key plugged into the computer or the phone's USB-C port.

What stays on your device

• Your profiles and their vaults: names, the public keys of your YubiKeys, their serial numbers, the vault descriptor and chain code, addresses seen, labels, notes, contacts, places, the owners you name, any photo or file you attach to a record, and a note of any transaction you have staged. All of it is sealed under one key kept in the Mac's Keychain, the iPhone's Keychain or the Android phone's hardware keystore, and also wrapped to each YubiKey you enrol, so a key and its PIN can open the app. A profile's name and picture are kept in the clear, like the app's own name.
• On your YubiKeys, if you seal a vault: one share of that vault's recovery record per key, in the card's certificate object. The share is encrypted under a secret the key keeps in a PIN-protected slot, so it cannot be read from a key someone merely holds. One share alone reveals nothing about the vault; enough shares to meet the vault's threshold, opened with their keys' PINs, reveal its descriptor, which shows what the vault holds. Shares written by builds before 19 September 2026 were not encrypted; the app identifies those and locks them in place.
• Your PIN, typed into the app, goes straight to the YubiKey over the local smart-card interface and is not stored or sent anywhere.
• Private keys never exist on the device. They are made on the YubiKey and stay there.
• A photo you attach is decoded, turned upright and re-saved before it is stored, so the location and camera details the camera wrote are gone, unless you tick the box to keep the file exactly as it is.

What leaves your device

To show balances, estimate fees and send transactions, the app talks to two kinds of server: an Electrum server and a block explorer. By default those are ours:

• electrum.mineracks.com and mempool.mineracks.com for mainnet
• a signet Electrum server and signet.mineracks.com for signet

Like any Bitcoin server, they necessarily see the addresses and transactions the app asks about, together with the internet address the request comes from and the time. We keep ordinary server logs for operating and securing the servers, and we do not use them to build profiles or sell them to anyone. They are rotated on a schedule and not kept longer than we need for that purpose.

If you would rather we saw nothing, open Settings in the app and enter your own Electrum server and explorer. The app will then talk only to those.

Three smaller services, each optional and each ours by default, work the same way:

• Prices. To show what an amount was worth, the app asks prices.mineracks.com for exchange rates. The request names a currency and a date, never an address or an amount.
• Places. If you turn Places on, the position of a transaction is recorded on the device to about a hundred metres. When you search for a place by name, the question goes to geocode.mineracks.com, which keeps no request logs. The little map is drawn on the device from map data served by tiles.mineracks.com, one zoom level, which also keeps no request logs. Places is off until you turn it on.
• Opening a transaction in your web browser shows it on the explorer in use, which will see that request as an ordinary page view.

Keeping the same profile on several devices (optional)

You can have a profile follow you between your Mac and your phones. It is off until you switch it on for that profile, in App settings, with one of your YubiKeys.

• What travels. The profile's vaults, labels, notes, contacts, places, owners, attached files, and its own name and picture. Settings, a half-built spend and the app's working cache stay on the device they were made on. Nothing that can spend ever leaves the keys.
• How it travels. Everything is encrypted on your device before it leaves, under a key that exists only on your devices and, sealed under each enrolled YubiKey's PIN-protected secret, on the keys themselves. The host holds ciphertext under names it cannot connect to a vault, an address or a file. What it necessarily sees is the size and timing of what is stored, and the internet address of each device that asks.
• Where it goes. By default to vss.mineracks.com, a storage service we run that speaks a published protocol (LDK's Versioned Storage Service). It is a setting: point the app at any host that speaks the same protocol, or leave sync off and nothing leaves the device.
• While every profile is closed. So that the profile picker can show a name or picture changed on another device, the app asks the sync host for them before the profile is opened. That request is the one thing the app says to anyone while nothing is open, and it is a switch per profile: turn it off and the picker shows the name and picture from the last time the profile was open on that device.
• Sealed vaults back their labels and attached files up the same way, under a key derived from the vault's own recovery shares, so any two of the vault's keys bring them back with it.

Our sync host keeps the same kind of ordinary server logs as our Bitcoin servers, for the same purpose and for no longer.

What we never collect

The app has no telemetry, no crash reporting of its own, no update checks that identify you, no accounts and no advertising identifiers. Notifications are the device's own local notifications and do not pass through us. The camera is used to read QR codes and to take a photo for a record, on the device, and for nothing else.

Builds from Apple and Google

Builds installed through TestFlight, the App Store or Google Play are delivered by Apple and Google, who see the install and may collect crash and usage reports under their own policies and your own device settings. We receive from them, at most, counts and crash reports with no personal details.

4. Bitcoin is public

Every Bitcoin transaction, including any you make with this app, is recorded on a public blockchain forever. That record is not held by us and is not covered by this notice, but it is worth remembering when you think about what is private.

5. Sharing and overseas disclosure

We do not sell or rent any information. Cloudflare, Google and Apple may process the technical data described above in countries other than Australia under their own policies. We do not otherwise send information overseas.

6. Your rights

You can ask us what, if anything, we hold about you, and ask for it to be corrected or deleted. Because the app keeps its data on your own devices, most of the time the answer is that we hold nothing beyond short-lived server logs and, if you use sync, records we cannot read, which you can delete by stopping sync on each device. If you have a complaint about how we handle information, tell us first and we will respond; if you are not satisfied you can contact the Office of the Australian Information Commissioner.

7. Changes

We will update this page if what the site or the app does changes. The date at the top is the date the current notice took effect.

8. Contact

Privacy questions can be sent to us through mineracks.com.