Vehicle Access Basics

Introduction

Vehicle access systems have evolved significantly over the last few decades — from simple mechanical keys to advanced proximity-based entry and start systems. While most new electric vehicles (EVs) today rely on digital or app-based keys, several models — especially in the lower price range — still use traditional methods such as physical keys or electronic key fobs.

This chapter gives an overview of the most common access systems found in EVs today, starting with legacy technologies and ending where digital key systems begin. Understanding these foundational systems is essential for grasping the strengths and limitations of EV security in general.

Mechanical Keys

Mechanical keys are the most basic form of vehicle access. The driver must physically insert a metal key into the door lock and ignition.

While nearly obsolete in most passenger vehicles, a few budget EVs and commercial models still use mechanical keys as part of a cost-saving strategy.

• Pros: Simple, reliable, low-tech
• Cons: No remote access, no alarm integration, no passive unlocking

Remote Keyless Entry (RKE)

Remote Keyless Entry systems use a key fob that communicates with the car via radio frequency (RF) when a button is pressed.

With RKE, the driver can unlock doors or open the trunk remotely, usually from a range of several meters. This system became standard in most vehicles from the early 2000s onward, including early EV models.

• Pros: Convenient compared to mechanical keys, adds basic remote features
• Cons: Requires manual button press, limited security (unencrypted in older systems)

Passive Keyless Entry and Start (PKE / Keyless Go)

Often referred to as "Smart Key" systems, passive entry allows the driver to unlock the vehicle simply by approaching with the key fob. The doors unlock when the handle is touched, and the vehicle can start with a push-button ignition — no need to remove the key from a pocket or bag.

This system is now widespread in mid- and high-end EVs, and it laid the groundwork for modern digital key systems.

• Pros: Highly convenient; unlock/start without using the fob directly
• Cons: Vulnerable to relay attacks if not paired with distance verification

Security Considerations

Each of these systems comes with its own strengths and weaknesses from a security perspective:

The biggest security risk associated with PKE systems is relay theft, where criminals use two wireless devices to extend the communication range between the vehicle and key fob — tricking the car into unlocking and starting without the owner's knowledge.

Looking Ahead

While traditional key systems still exist, they are rapidly being replaced by more secure and flexible digital solutions. In the next chapter, we explore Digital Key Technology, including BLE, NFC, and UWB systems — and how they enhance both convenience and security in modern EVs.