Limiting the devices with which a user can synchronise data in a cloud storage account to those on a list of devices

摘要

A user device sends a login request to a cloud based service. The request includes user details and a device identifier. The device identifier may be a CPU identifier. The service determines whether the device is currently authorised to synchronise with the users account by comparing the device identifier with a list of identifiers of devices that have already been authorised. If the device has been authorised, synchronisation with the device is enabled. Otherwise, the service determines whether the limit on the number of devices allowed to synchronise with the account has been reached. If not, the device is added to a list of authorised devices and synchronisation with the device is enabled. Otherwise, synchronisation is disabled. The service may send the device an authentication token, if synchronisation is enabled. Each account may have a different limit on the number of devices.