We chose this method because it requires trust of just one entity (the lambda end point we provide) rather than trust of each app that might interact with SimpleID's SDK. If the seed phrase is generated client-side within an app, that developer could hold onto that seed and use it maliciously.

Identities created through SimpleID can be used across multiple apps, so it's important to us that developers are only able to access data specific to their app (i.e. app-specific encryption keys).

The seed is generated on the lambda, encrypted client side and stored in our database.