Abstract: Methods, systems, and storage media client-to-client message synchronization are disclosed. Exemplary implementations may: in response to an indication of a state change for a state of an account on a first device being received through a user interface of the first device, receive the indication of the state change from the first device at a second device; update a state of the account on the second device based on the indication of the state change for the account on the first device; and cause display of a view of the user interface of the messaging application on the second device reflecting the updated state of the account on the second device.

Abstract: Methods, systems, and storage media providing equal signing authority between multiple devices of a single user in an end-to-end encrypted messaging system are disclosed. Exemplary implementations may generate an account key comprising a public account key and a private account key for onboarding a first user device of a first user to the end-to-end encrypted messaging system; upload the public account key to an encrypted server of the end-to-end encrypted messaging system; in response to a request to onboard a second user device to the end-to-end encrypted messaging system, establish a secure communication channel between the second user device and the first user device; send a copy of the private account key to the second user device from the first user device through the secure communication channel; and onboard a third user device to the end-to-end encrypted messaging system through either the first user device or the second user device.