Safe-Stop DEFR Contact
Patent pending · DPMA · September 2026

Safe-Stop Safety system for motor vehicles

No more vehicles used as weapons.

A tamper-proof, digitally signed radio signal stops exactly one vehicle. The vehicle verifies the signal itself, without internet, mobile network or GPS. Steering, brakes and hazard lights remain active.

Become a partner How it works
  • Short-range radio
  • Digital signature
  • Offline verification
Scenario: Christmas market
The problem

Today’s protective measures have gaps

Vehicles are deliberately used as weapons, for example in ramming attacks on public events. Or they become a danger unintentionally, like wrong-way drivers on the motorway.

Gap 01

Bollards and concrete barriers

High construction effort and inflexible for temporary sites. Emergency vehicles struggle to get through. As a result, many events become expensive or are no longer held at all.

Gap 02

GPS and mobile network systems

They fail in dead zones or under interference, cause ongoing costs and open up an additional attack surface.

Gap 03

Unsecured stop signals

Without secure authentication they could be manipulated. A forged signal must never be able to stop a car.

The goal: stop safely. No bollards, no network.

Applications

One system, four tasks

The transmitter can be a handheld device, a mobile stand-alone unit or a fixed transmitter mast. This lets the system adapt to events, roads or factory gates.

Illustration: Stand-alone units at the entrance to a Christmas market stop a vehicle while an ambulance passes through

Protect events

Mobile stand-alone units at the entrances instead of concrete barriers. Escape routes stay clear and emergency vehicles pass through unhindered.

Illustration: A transmitter mast at a motorway slip road stops a vehicle entering in the wrong direction

Stop wrong-way drivers

A transmitter mast at the motorway slip road detects the direction of travel and stops the vehicle before it becomes a danger.

Illustration: A barrier opens only for a vehicle with an active receiver

Control access

Status check without stopping: the barrier opens only for vehicles with an active receiver. Suitable for industrial sites and critical infrastructure.

Illustration: A number plate reader above the motorway detects a wanted vehicle, and only that vehicle is stopped

Targeted stops

A number plate reader detects a wanted getaway vehicle. Only that vehicle is stopped, making pursuits unnecessary.

Also: ending police pursuits and securing restricted zones and critical infrastructure. All scenarios in detail

Scenarios in detail

Five applications, step by step

Every scenario follows the same sequence: assess the situation, send a signed stop signal, bring the vehicle to a controlled stop.

Application 1 / 5

Protect events

  1. 1SITUATIONA vehicle is heading towards a crowded event area.
  2. 2ACTIONStand-alone units at the entrances send the signed stop signal.
  3. 3RESULTThe vehicle stops. Emergency vehicles with exemption status pass through.

Protection without concrete barriers. Escape routes stay clear.

Photo visualisation: A wrong-way driver is stopped at a motorway exit, a warning sign reads “Wrong-way driver stop system”
Application 2 / 5

Stop wrong-way drivers

  1. 1SITUATIONA vehicle enters the motorway the wrong way via an exit ramp.
  2. 2ACTIONA transmitter mast detects the wrong direction of travel and sends the stop signal.
  3. 3RESULTThe vehicle stops before reaching the carriageway. Steering and brakes remain active.

An unintentional danger stopped before a head-on collision occurs.

Photo visualisation: A vehicle passes the barrier at the entrance to a power plant
Application 3 / 5

Control access

  1. 1SITUATIONAccess to a restricted area, such as a power plant or industrial site.
  2. 2ACTIONThe barrier queries the receiver’s status without stopping the vehicle.
  3. 3RESULTAccess only for vehicles with an active, intact receiver.

Only vehicles that can be stopped at any time are granted access to sensitive areas.

Application 4 / 5

Targeted stops

  1. 1SITUATIONA wanted vehicle is travelling in moving traffic.
  2. 2ACTIONA number plate reader detects it. The stop signal applies only to its ID.
  3. 3RESULTOnly this vehicle stops; the rest of the traffic keeps moving.

Targeted, not blanket: each signal applies to exactly one vehicle.

Application 5 / 5

End police pursuits

  1. 1SITUATIONA fleeing vehicle endangers pedestrians and police officers.
  2. 2ACTIONOfficers send the signed stop signal using a handheld device.
  3. 3RESULTThe vehicle comes to a controlled stop, without a risky chase.

Pursuits end safely, for bystanders and officers alike.

Videos and photos are AI-generated visualisations of the application scenarios.

How it works

The key stays at headquarters

Only the central authorisation authority can generate a valid stop signal. The vehicle verifies it locally using a public key.

  1. 1encrypted connection

    Authorisation authority

    Holds the private key and signs the stop signal for exactly one vehicle. The private key never leaves the authorisation authority.

    ↓ encrypted internet connection
  2. 2short-range radio

    Transmitter

    Handheld device, stand-alone unit or transmitter mast. It does not know the key and only transmits the finished signature.

    ↓ short-range radio
  3. 3switching output

    In-vehicle receiver

    Verifies the signature with the public key, locally and without internet or GPS.

    ↓ switching output / engine control unit
  4. 4

    Vehicle stops

    Fuel or power supply is cut. Steering, brakes and hazard lights remain active.

Asymmetric signature (private / public) Timestamp and nonce against replay Factory-fitted or as a retrofit module
Tamper resistance

Only authorised signals stop a vehicle

  • Asymmetric signatureVehicles only know the public key. It can be used to reliably verify that a stop signal is genuine, but not to generate one.
  • Replay protectionTimestamp and nonce ensure that recorded signals are rejected.
  • Addressed to individual vehiclesEach signal applies to exactly one vehicle. All others ignore it.
  • Exemption status for emergency servicesPolice, fire and ambulance services pass through. The status can be revoked in case of misuse.
  • Limited transmit authorisationTransmitters only receive authorisations limited in time and number.

Verification in the vehicle

Simplified illustration

    Verification runs entirely in the receiver. It needs neither a network nor location data.

    Benefits

    Technically robust, socially effective

    Safe-Stop prevents a motor vehicle from being used as a weapon, whether deliberately or unintentionally.

    Network-independent

    Verification in the vehicle, without internet, mobile network or GPS. Works even in dead zones.

    Tamper-proof

    The private key stays at headquarters. Replayed signals are rejected.

    Targeted, not blanket

    Only the addressed vehicle is stopped. Emergency services have a clear way through.

    Retrofittable

    Can be integrated at the factory or installed as a module between battery and on-board power supply. Updates via app.

    Keep events possible

    Christmas markets and festivals can be secured with far less construction effort, instead of being scaled down or cancelled.

    Protect freedom

    Public gatherings can continue to take place safely. A contribution to an open, democratic society.

    Status and offer

    We are looking for partners for the next step

    The invention is patent pending and a working demonstrator is available. The next steps are expert validation, pilot applications and series production.

    1. Patent application filed

      German patent application with the German Patent and Trade Mark Office (DPMA): “Safety system for motor vehicles and method”.

    2. Transmitter and receiver up and running

      Microcontroller-based software with Bluetooth Low Energy and Ed25519 signatures. Security logic tested, including attack scenarios.

    3. Validation and pilot

      Expert meetings with live demonstrations, a pilot application with first users, talks on licensing or a development partnership.

    Security research

    Independent assessment of the cryptography and vehicle IT security, joint funded projects.

    Police and authorities

    Requirements from operational practice: tactics, legal basis, protection against misuse.

    Municipalities and event organisers

    Pilot application to protect markets, festivals and public gatherings.

    Automotive industry

    Suppliers and manufacturers as licensees for the receiver module, factory-fitted or as a retrofit.

    Fleets and insurers

    Truck and rental fleets with high damage potential, centrally retrofittable.

    Licensing Development partnership Pilot project Live demonstration
    Frequently asked questions

    What you should know

    Could the system be misused to stop arbitrary vehicles?

    Only signals signed by the central authorisation authority with its private key are executed. Transmitters do not know this key and only receive authorisations limited in time and number. Each signal applies to exactly one vehicle, and replayed signals are rejected.

    Is stopping a moving vehicle dangerous?

    The drive is cut while steering, brakes and hazard lights remain active. Exactly how stopping at high speed works in detail will be defined together with manufacturers and security researchers.

    Does it work without a network?

    Yes. Verification takes place locally in the vehicle, without internet, mobile network or GPS. Only the transmitter needs a secure connection to the authorisation authority beforehand.

    Does this mean vehicles are being monitored?

    No. The system is designed for stopping, not tracking. It does not require continuous transmission of location data.

    What about emergency vehicles?

    Police, fire and ambulance services receive an exemption status. It can be revoked in case of misuse.

    On what legal basis could the system be used?

    Voluntary applications, for example on industrial sites or in fleets, can be governed by contract. Use by public authorities requires a basis in police and road traffic law; mandatory fitting would be possible via EU type approval. We are clarifying these questions together with authorities and partners.

    Which cybersecurity requirements apply?

    Vehicle manufacturers must comply with UN Regulations R155 (cybersecurity management system) and R156 (software updates). The receiver module will be integrated into these processes.

    Contact

    Let’s talk about working together

    We would be happy to present the system to you in a meeting of around 30 minutes, either on site with a live demonstration or via video call.

    We share technical details once a non-disclosure agreement has been signed.

    Dr. Thorsten Caus

    Inventor · 83361 Kienberg, Germany

    caus@safe-stop.de
    +49 171 4640274

    Manfred Gmeindl

    Inventor · 83361 Kienberg, Germany

    gmeindl@safe-stop.de
    +49 179 7862519