CalcLockHow it works
An ordinary calculation. A private way in.
Your exact equation opens your vault. Here is what happens behind the calculator.
1. Calculate as usual.
CalcLock works as an everyday calculator. Enter your vault’s exact equation and tap equals: the normal answer appears. Tap equals again to open that vault.
Your equation and your device work together.
The app combines the exact equation with a secret generated on the device, then runs it through key-derivation steps before using AES-256-GCM to encrypt the vault’s files and their names.
So two equations with the same answer, like 123+123 and 200+46, produce different keys and open different vaults.
That device secret is stored in the iPhone’s Keychain and doesn’t sync to another device.
It also means that forgetting the equation or losing the device means losing access: there’s no recovery or portable backup.
Designed to stay a calculator.
The first equals press still shows a normal answer. There is no vault directory on the calculator screen: the second equals press takes you straight to the collection for that equation. When you leave the app, it returns to the calculator.
What you need to know.
Forget the equation or lose the device and you lose access. There is no recovery or portable backup, so keep independent copies of important photos.
A simple equation is easier to guess. This encryption design has not had an independent security audit, and a discreet interface does not make the app undiscoverable.