Method, device and system for secure distance measurement

Method for secure distance measurement comprising the following steps:

• transmitting from a verifier to a prover a challenge message comprising a challenge bit sequence;
• transmitting from the prover to the verifier a response message comprising a response bit sequence;
• verifying, in the verifier, the response message on the basis of the response bit sequence;
• and
• determining, in the verifier, the distance between the verifier and the prover on the basis of the time difference between the challenge message and the response message;
• wherein a transmitted message containing a verifying bit sequence (VBS) is transmitted from a transmitting device to a receiving device, wherein either the transmitted message is the challenge message containing the challenge bit sequence as the verifying bit sequence transmitted from the verifier as the transmitting device to the prover as the receiving device or the transmitted message is the response message containing the response bit sequence as the verifying bit sequence transmitted from the prover as the transmitting device to the verifier as the receiving device, wherein the transmitted message is encoded on a transmission signal and transmitted by the transmitting device, wherein a bit of the transmission message is transmitted in the transmission signal by a pulse with a pulse modulation parameter with two pulse states, wherein the receiving device receives a receiving signal containing the encoded transmitted message, wherein the receiving device detects the transmitted message in the receiving signal and decodes the verifying bit sequence from the receiving signal;
• wherein
• the receiving device based on the transmission format of the transmitted message and based on the detected transmitted message in the receiving signal defines sub-periods in the receiving signal in which the first path of the pulses of the bits of the verifying bit sequence of the transmitted message are expected in the receiving signal;
• and
• the receiving device decodes a pulse state of a pulse of a bit of the verifying bit sequence based on the receiving signal received during one of the defined sub-periods belonging to the pulse to be decoded.