How your memories actually stay private

Open a typical notes app or a backed-up photo library and, in principle, the company behind it can read what's inside. It's how the plumbing usually works: your content is encrypted on the way to their server, then decrypted the moment it lands so it can be indexed, searched or restored. Memory Jar is built differently, and it's worth being specific about how.

Every jar you keep sits in an encrypted database on your phone, using SQLCipher, an encrypted version of the database format most Android apps already use for local storage. The key that opens it lives in the Android Keystore, hardware on the device built to hold cryptographic keys without exposing them, even to the app that requests them. Nothing is written to disk as plain text. If you never turn on backup or share a keepsake, nothing about that jar ever leaves your phone.

You can also lock the app itself behind your fingerprint or your face, a separate check from your phone's own lock screen. Someone who picks up your phone while it's awake still can't open a jar without clearing that second gate.

Turn on cloud backup and the data is still encrypted before it leaves your device, with a key derived from your own passphrase rather than one we hold. Our server ends up storing a scrambled blob it has no way to open. Break into that server tomorrow and all you'd find is ciphertext, unreadable without a key that never left your phone.

Sharing works on the same principle. When you seal a jar and send someone the link, the key that opens it travels inside the link, in the part after the "#", which a browser never sends to a server. Only someone holding that exact link can decrypt what's on the other end.

Keeping a jar on your phone needs no account, and Memory Jar works fully offline from the first line you write; only backup and shared links involve an account and our server. That default is unusual for a digital memory jar in 2026, when most apps expect a server relationship before you've written a single word.

The same model applies to any jar, whichever kind you're keeping. For how it looks in practice, there are separate pages for parents, for long-distance relationships, and for keeping a jar just for yourself.