A method comprising: executing, by data processing hardware (220, 920), a clock for an operation period starting at a first time (T 0) and ending at a final time (T F) and determining a current time by using said clock; determining, by the data processing hardware, a current time interval of a plurality of time intervals corresponding to the current time; receiving, at the data processing hardware (220, 920), a communication connection request from a remote device (110, 300) at a communication time corresponding to the current time interval of the plurality of time intervals sequentially covering the operation period, each time interval having an associated authentication value, and the communication connection request comprising a commitment value; determining, by the data processing hardware (220, 920), whether the commitment value matches the authentication value associated with the current time interval corresponding to the communication time; and establishing a communication connection between the data processing hardware and the remote device when the commitment value matches the authentication value associated with the current time interval corresponding to the communication time; processing the communication at the data processing hardware (220, 920) when the commitment value matches the authentication value associated with the current time interval corresponding to the communication time, wherein the communication includes global positioning system data including position and time information; wherein the authentication value associated with the current time interval corresponding to the communication time comprises a hash digest of a hash function applied to the authentication value associated with a sequentially subsequent time interval of the plurality of time intervals. executing, by data processing hardware (220, 920), a clock for an operation period starting at a first time (T 0) and ending at a final time (T F) and determining a current time by using said clock; determining, by the data processing hardware, a current time interval of a plurality of time intervals corresponding to the current time; receiving, at the data processing hardware (220, 920), a communication connection request from a remote device (110, 300) at a communication time corresponding to the current time interval of the plurality of time intervals sequentially covering the operation period, each time interval having an associated authentication value, and the communication connection request comprising a commitment value; determining, by the data processing hardware (220, 920), whether the commitment value matches the authentication value associated with the current time interval corresponding to the communication time; and establishing a communication connection between the data processing hardware and the remote device when the commitment value matches the authentication value associated with the current time interval corresponding to the communication time; processing the communication at the data processing hardware (220, 920) when the commitment value matches the authentication value associated with the current time interval corresponding to the communication time, wherein the communication includes global positioning system data including position and time information; wherein the authentication value associated with the current time interval corresponding to the communication time comprises a hash digest of a hash function applied to the authentication value associated with a sequentially subsequent time interval of the plurality of time intervals.