Why Electronic Car Keys Evolved From Simple Proximity Keys To Pricey Button-Filled Fobs

A "key" feature of today's car keys is not having to physically touch them to enter or start the car, thanks to developments like RFID proximity technology (which is short for radio frequency identification). That feature is especially nice since key fobs are dirtier than you think. They can cost a small fortune to replace, and they've changed from being simple locking and unlocking remotes as manufacturers have sought to offer greater convenience and vehicle security. 

Some of the earliest car keys were developed in 1910 by German engineering firm Bosch. They were designed to complete the electrical circuit required to crank start a car, helping to prevent theft. Separate key locks for doors started popping up in the 1920s while electric buttons replaced starter cranks. Eventually, Chrysler gave us the first modern car key in 1949. It both fit into an ignition tumbler and activated the electrical starter, replacing the push-button start mechanism that most new cars have circled back around to. 

Mechanical keys were gradually paired with remote fobs through the late 1980s and 1990s, then fobs became part of the keys themselves by the 2000s. There have been plenty of weird car keys produced throughout history, and our pricey, button-filled fobs perform multi-function sorcery compared to their ancestors. These days, keys come with instructional videos to show you how  to use modern features like remote locking, remote starting, automatic parking, and remote climate control. Meanwhile, digitally-authenticated proximity signals take care of the security. 

Key fobs and key-based ignition immobilization emerged in the 1980s, when the 1982 Renault Fuego pioneered remote convenience. Chevrolet also embedded resistors in 1986 Corvette keys to thwart theft, and the 1990 Mercedes-Benz SL was the first to combine a key blade and fob into a switchblade design. On the convenience side, General Motors provided fobs with remote sliding door control for minivans in 1993 and offered proximity locking and unlocking on the 1993 Corvette. The 1998 Mercedes-Benz S-Class upped the ante with keyless proximity ignition. While this went on, Volkswagen focused on security, baking a vehicle-specific transponder into its switchblade keys in the 1999 Golf. 

At the turn of the century, automakers continued to move towards bolder multi-function fobs, providing greater convenience and security features. A funky Saab fob for the 2003 9-3 replaced the metal key blade with a nub, requiring a twist in the center console ignition to start the car. Mercedes and Lexus designed credit card-style passive keys, while GM made remote start available on the 2004 Chevrolet Malibu straight from the factory. Chrysler made a fob that combined transponder and proximity capabilities into one device for 2008-2016 vehicles. And today, Tesla offers a key fob that looks like a slightly melted miniature of the car.

RFID fobs allow manufacturers to offer more vehicle security than older designs. Wirelessly-transmitted, vehicle-specific serial numbers and key codes can't be replicated like mechanical keys. Even so, RFID keys have been subject to remote relay hacks that intercept the authentication signal, making theft a breeze. Putting keys in a Faraday box or pouch prevents this, though it blocks the signal for you, too. Regardless, transponders do offer a real security benefit. When word got out that many Hyundai and Kia keys didn't feature immobilizer chips, thefts skyrocketed throughout 2021 and 2022, as the Associated Press reported. Having engine immobilizers can lower insurance rates, and some international markets outside the U.S. require them.

As for best key fob designs, there are plenty to check out. Volvo offers a small, buttonless, waterproof key for active folks to use as a fob substitute. BMW has the huge Display Key that's basically a smartphone app and screen, minus the smartphone. This provides at the control and configuration that many owners want — and that manufacturers want to provide.

The convenience and security push that drove the key fob button craze is now fueling the move to eliminate keys completely in favor of digital smartphone keys that rely on passwords and biometrics. Tesla's Model 3 was the first to go this route, and Apple announced at its 2025 WWDC that over 20 brands signed on to offer owners the option of using iPhones and Watches as car keys. Even if that future fully arrives, though, we can probably expect that some type of physical key will still exist as a backup.