Your memories should outlive the phone they live on.
Cairn keeps your photos and the moments around them in a vault only your key can open. Add them once. They stay, sealed, for as long as you want them, and long after the device is gone.
- End-to-end encrypted
- Zero-knowledge servers
- Yours to export, always
A moment on its way into the vault. Watch it seal.
Three honest steps, and none of them trust us with the contents.
Add the moment
Drop in a photo, a short clip, a voice note, the date and who was there. Cairn holds the moment, not just the file, so a birthday reads as a birthday ten years from now.
It seals itself
The instant it lands, the moment is encrypted on your device and sealed into your vault. We store sealed bytes. What is inside is unreadable to us, to our hosts, to anyone who is not holding your key.
Only your key opens it
Your key is derived from a passphrase only you know, never sent to us. Open a moment and it unseals in front of you. Close the app and it seals again. Lose the passphrase and even we cannot get in, which is the point.
A vault that reads like a memory, not a hard drive.
Inside, moments sit on a calm timeline. Search by a face, a place, a year, or a word you wrote at the time. Everything you see here was decrypted a moment ago, in your browser, with your key.
One evening. A hundred phones. A single sealed album.
The best photos of a wedding are on other people's phones, and most of them you never see. Event mode opens a shared vault for a day. Everyone at the table adds their stone to it. When the night ends, it seals.
- 01
Open the album
Name the event, set the date, and Cairn makes a vault with its own key. No accounts for guests, no app to install.
- 02
Everyone adds
Guests scan a card on the table and drop in their photos and clips as the evening happens. Each one seals as it arrives.
- 03
It closes at midnight
At an hour you choose the album seals for good. No late edits, no quiet deletions. What was there is what stays.
- 04
The key goes home
The couple, or whoever hosted, holds the key. They decide who else ever opens it. Cairn never can.
Add your photos to
Mara & Theo
14 September
Scan to add. Seals at midnight.No app, no account.
The signature
Watch a life get put beyond reach.
This is a family's year, scrolling past a seal. Each moment you pass is encrypted and locked in front of you. It is the same act that happens, invisibly, every time you add one.
Priced so keeping something is never the reason you lose it.
Every tier is end-to-end encrypted and exportable. You are paying for room and for keyholders, never for the right to read your own moments.
Personal
Free
5 GB sealed
Enough for the photos you would be devastated to lose.
- End-to-end encrypted vault
- Timeline, people and place search
- Export the whole vault anytime
- One device key, add more later
For one person keeping the moments that matter most.
Family
Most keep this£6per month
500 GB sealed
One vault the whole household adds to, each with their own key.
- Everything in Personal
- Up to 6 keyholders, no shared password
- Shared and private moments in one vault
- A named heir who inherits access
For a family who wants one place the years actually land.
Event
£19per event
Unlimited for 30 days
A shared album that opens for a day and seals for good.
- Guest uploads with no app or account
- A printable table card and QR
- Automatic seal at an hour you set
- The host keeps the only key
For a wedding, a wake, a reunion, once.
Trust & security
The parts most services put in the small print.
A vault is only worth the promises behind it. Here are ours, in plain words, because if you cannot understand how it is protected you cannot trust that it is.
- End-to-end encrypted, always
- Zero-knowledge servers
- Open, documented vault format
- Independent security audits
- Who holds the key?
- You do, and only you. Your key is derived from your passphrase on your own device and is never transmitted to Cairn. We hold sealed bytes and no way to open them.
- What can Cairn actually see?
- The size of your vault and when you last opened it. Not a single photo, caption, face, date, or name inside it. This is not a policy we choose to keep. It is a thing we are unable to break.
- What if Cairn goes out of business?
- Your vault is not hostage to us. The format is open and documented, and the app can run against a vault with no Cairn server at all. If we disappear, you still hold both the bytes and the key to read them.
- Can I leave and take everything?
- Any time, in one click, as ordinary decrypted files with the dates and captions intact. No lock-in, no export queue, no fee to get your own memories back.
- How is it encrypted?
- XChaCha20-Poly1305 for each moment, keys wrapped with Argon2id from your passphrase. Standard, audited, boring cryptography. We publish our whitehat findings, not just our badges.
- What happens when I die?
- You name an heir who receives the key through a process you set up while you are alive. The moments pass to them the way a locket would, not to a company, not to no one.