Kin Album
Security
Updated September 24, 2026
How your photos are protected
Photos and videos are encrypted on your iPhone before they are uploaded. Each file gets its own encryption key; that key is wrapped under your family’s album key, and the album key is only ever granted to your family members’ devices — sealed to keys held on their iPhones and in the web browsers they use to open the album. Our servers store ciphertext and wrapped keys. We cannot decrypt your photos or videos, and neither can anyone who compromises our storage, with the two exceptions below: email preview copies, and invitations sent by email.
A few things sit outside that encryption so the product can work, and we say so plainly:
- Captions, comments, and names are stored readably.
- Email preview copies. While anyone in an album gets photos in their emails — an album admin’s choice, on by default for a relative who only has email — a preview-size copy of every photo posted to that album, by every member, is made outside the encryption and stored with us, beside the encrypted originals, so the emails can show it. Each copy is deleted about 30 days after its photo was posted, or within a day of photos in emails being turned off for everyone in the album. Until then, a breach of our storage would expose those copies.
- Invitations sent by email. An invitation emailed from the iPhone app carries, in its link, a secret made for that invitation, which unlocks a copy of the album key we store for it. The app hands that link to our server, which sends the email through our email provider, so for these invitations we are not zero-knowledge: while that request is handled, our server could in principle recover the album key. The link stops working 14 days after it is sent.
- Push notifications never contain a photo, a caption, or the text of a comment.
The full design, including key rotation and what happens when someone is removed from an album, is documented and available to security researchers on request.
The encryption uses standard, well-studied primitives: Apple’s CryptoKit on the iPhone, and the browser’s built-in Web Crypto on the web. We do not invent our own ciphers. Independent review of the design is part of our roadmap; findings from good-faith research are welcome below.
Reporting a vulnerability
If you believe you have found a security issue in Kin Album, email security@kinalbum.com. Include enough detail to reproduce the issue. We will acknowledge your report within 3 business days, keep you informed as we investigate, and credit you when a fix ships if you would like credit.
We will not pursue or support legal action against good-faith security research that respects our users: do not access other families’ data beyond what is needed to demonstrate the issue, do not degrade the service, and give us reasonable time to fix before public disclosure. Machine-readable details live at /.well-known/security.txt.