US Patent 11706219 Secure session sharing between computing devices

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for authenticating a first computing device to access a secure account. Receiving a request from a second computing device to be authorized to access the secure account. Providing, to the second computing, first data that represents a first machine-readable code for presentation by the second computing device. Receiving, from the first computing device, second data that represents a second machine-readable code as read by the first computing device. Authorizing the second computing device to access the secure account in response to determining that the second data accurately represents the first machine-readable code as sent to the second computing device.