A Proof-of-Trust-System comprising: • a centralised system, comprising a connector; • at least one Identification Device comprising: - a Token comprising a memory for storing information of a person or object, such information comprising Identification Data comprising a first subset representing security Clearance Data indicating that the person or object is allowed to perform a valid action or obtain a valid status, said Identification Data being arranged to uniquely identify the person or object; and, - a Validator comprising a display, a processor unit, a memory, a Validator clock and Validator communication means (25,26) for interacting with the Token and with the Connector of the Centralized System; wherein the connector is configured during an initialisation phase, whereby the validator is connected via the validator communication means to the connector, for securely transferring data between the Centralized System and the Validator, such data comprising a clock synchronization signal for synchronizing the Validator clock to a Centralized system clock of the Centralized System, and Clearance Rules specifying whether the Token, based on the Clearance Data stored in the Token, can be given a specific Clearance Status that indicates that the object or person is allowed to perform an action or obtain a valid status; wherein the processor unit of the validator is configured for calculating a Clearance Status using a Clearance Function stored in the validator memory based on the Clearance Data obtained from the Token via the communication means and the Clearance Rules obtained from the Centralised system through the connector via the communication means; wherein the validator is further configured for displaying a first security code, referred to as the Indicator-of-Clearance code or IoC code, indicating the Clearance Status of the Token, whereby the first security code is generated by the processor unit of the validator using an Indicator-of-Clearance Function stored in the validator memory based on the Clearance Status and the Validator Clock, wherein the data being securely transferred during the initialization phase between the centralized system and the validator further comprises a set of time rules, wherein the processor unit of the validator is configured for calculating, based on the set of time rules obtained from the centralised system through the connector via the communication means and the validator clock, a set of time intervals, referred to as a set-of-time-points, using a time function stored in the validator memory, wherein said set-of-time-points are provided as input to the indicator-of-clearance function such that respective indicator-of-clearance codes are generated for each of the set-of-time-points. • a centralised system, comprising a connector; • at least one Identification Device comprising: - a Token comprising a memory for storing information of a person or object, such information comprising Identification Data comprising a first subset representing security Clearance Data indicating that the person or object is allowed to perform a valid action or obtain a valid status, said Identification Data being arranged to uniquely identify the person or object; and, - a Validator comprising a display, a processor unit, a memory, a Validator clock and Validator communication means (25,26) for interacting with the Token and with the Connector of the Centralized System; - a Token comprising a memory for storing information of a person or object, such information comprising Identification Data comprising a first subset representing security Clearance Data indicating that the person or object is allowed to perform a valid action or obtain a valid status, said Identification Data being arranged to uniquely identify the person or object; and, - a Validator comprising a display, a processor unit, a memory, a Validator clock and Validator communication means (25,26) for interacting with the Token and with the Connector of the Centralized System;