Can I Unlock Other People's Cars With My Remote?

iStock/dobok
iStock/dobok

Jason English, our esteemed editor, wonders, "How many other Camrys would my remote unlock? Is it really 1:1, or is there a chance my fob would open a Camry in Phoenix or Toronto?"

When you push a button on your car remote or garage door opener, a radio transmitter inside sends a signal containing a numeric code to a receiver in the car (or in the garage). When it gets the signal, the receiver tells the car (or the garage door controls) to lock or unlock (or open or close)—or whatever it's supposed to do given the button you pushed.

When remote garage door openers first came out in the 1950s, the transmitters in the remotes sent out a single signal. This was all well and good as long as you were the only person on your block with a garage door opener. But as they became more common, you could open any garage you wanted, because all remotes worked on the same signal. A security breakthrough came 20 years later when DIP switches—sets of eight manual electric switches packaged in a group and attached to a printed circuit board—were added. By setting the eight switches to a certain arrangement inside both the transmitter and the receiver, you had some control over the 8-bit code that they shared. The DIP switches could provide 256 possible codes. So while some security was provided, areas with lots of garage door remotes were still prone to code doubling and people opening up their neighbors' doors.

Early remote entry systems for cars were slightly more advanced. The system for each car had a unique code set by the manufacturer and used by that car's transmitter-receiver pair alone. The ratio really was 1:1. Just as my car lock or yours wouldn't open for Jason's key, our receivers wouldn't have responded to his transmitter's signal. These systems had their own problem: while the codes were unique to their cars, the same code was transmitted every time you used the remote. A radio transceiver called a "code grabber" could be used to intercept, store and retransmit the code later on. It was like having your key stolen and copied, without you knowing, while you were putting it in the keyhole and opening the door.

To combat the problem, manufacturers began using rolling codes (or hopping codes) in the mid-1990s. Instead of using a single fixed code, these newer systems use a set of rolling codes that change every time the remote is used. Now when you use the remote, the transmitter sends the current code to the receiver (most systems use 40-bit codes or longer, allowing for more than 1 trillion different combinations). If the receiver gets the current code, it responds; if not, it does nothing. The transmitter and receiver then "roll" the code using the same pseudorandom number generator (PRNG). When the transmitter sends the current code, it uses the PRNG to create a new code and remembers it. After receiving the current code, the receiver uses the same PRNG with the same original seed (the number that initiates the PRNG) to generate a new code. Using this method, the transmitter and the receiver generate matching sequences of codes and are synchronized (and, of course, all the information that's transmitted is encrypted).

What if you press a button on the remote while you're away from the car, generating a new code on the transmitter and desynchronizing the system? The receiver forgives your human error and accepts any of the next X valid codes in the code sequence (the number of "look-ahead" codes the receiver accepts varies among manufacturers). Push the button one too many times, though, and the receiver will ignore the remote and you'll have to resync the system.

Modern remote keyless entry systems are pretty secure, but there is a slight chance Jason could open another Camry if he wants to walk up to one and press the unlock button on his remote (assuming it uses a 40-bit code) one trillion, ninety-nine billion, five hundred eleven million, six hundred twenty-seven thousand, seven hundred and seventy-six times, running through all the possible codes his remote could transmit until one works (assuming he can hit the button once every second without taking any breaks, he'll need just shy of 34,842 years to do so). He'll also have to hope that the Camry he's trying to open has a receiver that uses a 40-bit like his remote, and isn't a newer model that might use a 66-bit code with 7.3 x 1019 possible codes.

10 Products for a Better Night's Sleep

Amazon/Comfort Spaces
Amazon/Comfort Spaces

Getting a full eight hours of sleep can be tough these days. If you’re having trouble catching enough Zzzs, consider giving these highly rated and recommended products a try.

1. Everlasting Comfort Pure Memory Foam Knee Pillow; $25

Everlasting Comfort Knee Pillow
Everlasting Comfort/Amazon

For side sleepers, keeping the spine, hips, and legs aligned is key to a good night’s rest—and a pain-free morning after. Everlasting Comfort’s memory foam knee pillow is ergonomically designed to fit between the knees or thighs to ensure proper alignment. One simple but game-changing feature is the removable strap, which you can fasten around one leg; this keeps the pillow in place even as you roll at night, meaning you don’t have to wake up to adjust it (or pick it up from your floor). Reviewers call the pillow “life-changing” and “the best knee pillow I’ve found.” Plus, it comes with two pairs of ear plugs.

Buy it: Amazon

2. Letsfit White Noise Machine; $21

Letsfit White Noise Machine
Letsfit/Amazon

White noise machines: They’re not just for babies! This Letsfit model—which is rated 4.7 out of five with nearly 3500 reviews—has 14 potential sleep soundtracks, including three white noise tracks, to better block out everything from sirens to birds that chirp enthusiastically at dawn (although there’s also a birds track, if that’s your thing). It also has a timer function and a night light.

Buy it: Amazon

3. ECLIPSE Blackout Curtains; $16

Eclipse Black Out Curtains
Eclipse/Amazon

According to the National Sleep Foundation, too much light in a room when you’re trying to snooze is a recipe for sleep disaster. These understated polyester curtains from ECLIPSE block 99 percent of light and reduce noise—plus, they’ll help you save on energy costs. "Our neighbor leaves their backyard light on all night with what I can only guess is the same kind of bulb they use on a train headlight. It shines across their yard, through ours, straight at our bedroom window," one Amazon reviewer who purchased the curtains in black wrote. "These drapes block the light completely."

Buy it: Amazon

4. JALL Wake Up Light Sunrise Alarm Clock; $38

JALL Wake Up Light Sunrise Alarm Clock
JALL/Amazon

Being jarred awake by a blaring alarm clock can set the wrong mood for the rest of your day. Wake up in a more pleasant way with this clock, which gradually lights up between 10 percent and 100 percent in the 30 minutes before your alarm. You can choose between seven different colors and several natural sounds as well as a regular alarm beep, but why would you ever use that? “Since getting this clock my sleep has been much better,” one reviewer reported. “I wake up not feeling tired but refreshed.”

Buy it: Amazon

5. Philips SmartSleep Wake-Up Light; $200

Philips SmartSleep Wake-Up Light
Philips/Amazon

If you’re looking for an alarm clock with even more features, Philips’s SmartSleep Wake-Up Light is smartphone-enabled and equipped with an AmbiTrack sensor, which tracks things like bedroom temperature, humidity, and light levels, then gives recommendations for how you can get a better night’s rest.

Buy it: Amazon

6. Slumber Cloud Stratus Sheet Set; $159

Stratus sheets from Slumber Cloud.
Slumber Cloud

Being too hot or too cold can kill a good night’s sleep. The Good Housekeeping Institute rated these sheets—which are made with Outlast fibers engineered by NASA—as 2020’s best temperature-regulating sheets.

Buy it: SlumberCloud

7. Comfort Space Coolmax Sheet Set; $29-$40

Comfort Spaces Coolmax Sheets
Comfort Spaces/Amazon

If $159 sheets are out of your price range, the GHI recommends these sheets from Comfort Spaces, which are made with moisture-wicking Coolmax microfiber. Depending on the size you need, they range in price from $29 to $40.

Buy it: Amazon

8. Coop Home Goods Eden Memory Foam Pillow; $80

Coop Eden Pillow
Coop Home Goods/Amazon

This pillow—which has a 4.5-star rating on Amazon—is filled with memory foam scraps and microfiber, and comes with an extra half-pound of fill so you can add, or subtract, the amount in the pillow for ultimate comfort. As a bonus, the pillows are hypoallergenic, mite-resistant, and washable.

Buy it: Amazon

9. Baloo Weighted Blanket; $149-$169

Baloo Weighted Blanket
Baloo/Amazon

Though the science is still out on weighted blankets, some people swear by them. Wirecutter named this Baloo blanket the best, not in small part because, unlike many weighted blankets, it’s machine-washable and -dryable. It’s currently available in 12-pound ($149) twin size and 20-pound ($169) queen size. It’s rated 4.7 out of five stars on Amazon, with one reviewer reporting that “when it's spread out over you it just feels like a comfy, snuggly hug for your whole body … I've found it super relaxing for falling asleep the last few nights, and it looks nice on the end of the bed, too.” 

Buy it: Amazon 

10. Philips Smartsleep Snoring Relief Band; $200

Philips SmartSleep Snoring Relief Band
Philips/Amazon

Few things can disturb your slumber—and that of the ones you love—like loudly sawing logs. Philips’s Smartsleep Snoring Relief Band is designed for people who snore when they’re sleeping on their backs, and according to the company, 86 percent of people who used the band reported reduced snoring after a month. The device wraps around the torso and is equipped with a sensor that delivers vibrations if it detects you moving to sleep on your back; those vibrations stop when you roll onto your side. The next day, you can see how many hours you spent in bed, how many of those hours you spent on your back, and your response rate to the vibrations. The sensor has an algorithm that notes your response rate and tweaks the intensity of vibrations based on that. “This device works exactly as advertised,” one Amazon reviewer wrote. “I’d say it’s perfect.”

Buy it: Amazon

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

What Should You Do In the Unlikely Event You Meet An Alien?

If you ever find yourself in a Mac and Me-type situation, it's best to know what to do.
If you ever find yourself in a Mac and Me-type situation, it's best to know what to do.
Shout! Factory

What do you do if you encounter an alien? It’s obviously fairly unlikely, but nothing is impossible—after all, you can’t spell meet without ET. If there’s a stray dog in your backyard, there’s a set procedure to follow. But what if, rather than a mere hound, it’s a creature from another world?

“If you meet an alien in your backyard, my recommendation is to get out of town,” Seth Shostak, senior astronomer at the SETI Institute, an organization seeking to explore, understand, and explain the origin and nature of life in the universe, tells Mental Floss. “If they have the technology to come here, they’re so far beyond us that whatever they want to do, they're going to do. If they’re here to take over the planet, it’s going to be pretty hard to stop them.”

A creature from another planet lurking on your property means not only that there is intelligent life elsewhere, but that it is at a significantly more technologically advanced stage than humanity. A species with the ability to not only travel the enormous distances involved (the closest star to our sun, which does have some potentially life-supporting planets, is 4.2 light years away), but also land undetected in your flowerbed would simply have us outclassed.

As you flee, however, you might want to contact the emergency services. If, for instance, the alien is aflame—and given that we know nothing about what form such a creature might take, there’s no real reason it wouldn’t be—you might want to give the fire department a call, for example. Moving up a notch, the FBI and Department of Defense are frequently contacted with flying saucer sightings, as are the UK’s Royal Air Force and Ministry of Defence and, well, pretty much every other emergency service in every country. This is because there is no set protocol, no universally agreed-upon decree of exactly what to do in the event of a close encounter.

“As far as I know, there is no policy for that, because that would be like Neanderthals having a policy for if the U.S. military decided to take them on,” Shostak says. “If aliens were actually landing here, we could have whatever policy we wanted and it wouldn’t be likely to help much.”

A scene from E.T.
Universal Pictures Home Entertainment

Whatever Hollywood might tell us, the likelihood is that any contact we have with beings from another world will be limited to picking up a signal from deep space, rather than encountering the long fingers and warm heart of a charming 3-foot-tall alien rustling around in shrubbery. As luck would have it, there is a protocol for that; it's known as the Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence [PDF] and was put together by the International Academy of Astronautics with input from Shostak.

The protocols are also entirely voluntary, with no force of law behind them and nobody under any obligation to adhere to them. What if you don’t want to tell everybody? What if you fancy keeping information about life beyond Earth to yourself for a while? You’re the one talking to aliens, after all—surely you can make a few bucks out of the situation ...

As Shostak points out, this kind of thinking is unlikely to get you anywhere. Given the distances involved, and the power required to transmit information that far, you aren’t going to be in any kind of dialogue. Secondly, revealing that you have detected a transmission is useless without it being verified and studied—the process of which, by necessity, involves making that information available to the world. Thirdly, interpreting any alien message will be a mammoth task involving a lot of work from a lot of people, a task unlikely to ever reach a definitive conclusion. “It would depend on whether they were trying to make it easy,” Shostak says.

Anything you discovered would belong to humanity as a whole, as we collectively tried to figure out what the signal meant, both literally and existentially, knowing we are not alone in the universe. You’d get to be the first person to prove there was intelligent life beyond Earth, which might be mildly less exciting in the short term than getting attacked by a little green man while taking the trash out, but at least you’d live to tell the tale.