US Patent 11182463 Method to create a trusted pool of devices

The present invention relates to a method to create, by a service provider, a trusted pool of security devices adapted to perform cryptographic operations in a secure service, comprising the steps of: for a service provider, setting up a secure service by allocating a first device in the service, setting the first security device's clock to a reliable time source, creating an internal secure-service-object defining at least a service clock-instance and service-specific cryptographic keys and certificates used to protect communication between a resource owner's security application and a security device part of the secure service, said secure-service-object being maintained by the security device internally preventing any service provider from arbitrarily changing it, when additional security devices are required, for the service provider, adding additional security devices to the service through ensuring the two security devices' clocks are synchronized by setting the target security device's clock to an accurate time value and defining, in the secure-service-object, a max-delta-time and a max-daily-correction per day values limiting the drift between two devices of the pool.