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

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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.

iStock_000003906364XSmall-carsTo 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.

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science
6 Radiant Facts About Irène Joliot-Curie
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Hulton Archive/Getty Images

Though her accomplishments are often overshadowed by those of her parents, the elder daughter of Marie and Pierre Curie was a brilliant researcher in her own right.

1. SHE WAS BORN TO, AND FOR, GREATNESS.

A black and white photo of Irene and Marie Curie in the laboratory in 1925.
Irène and Marie in the laboratory, 1925.
Wellcome Images, Wikimedia Commons // CC BY 4.0

Irène’s birth in Paris in 1897 launched what would become a world-changing scientific dynasty. A restless Marie rejoined her loving husband in the laboratory shortly after the baby’s arrival. Over the next 10 years, the Curies discovered radium and polonium, founded the science of radioactivity, welcomed a second daughter, Eve, and won a Nobel Prize in Physics. The Curies expected their daughters to excel in their education and their work. And excel they did; by 1925, Irène had a doctorate in chemistry and was working in her mother’s laboratory.

2. HER PARENTS' MARRIAGE WAS A MODEL FOR HER OWN.

Like her mother, Irène fell in love in the lab—both with her work and with another scientist. Frédéric Joliot joined the Curie team as an assistant. He and Irène quickly bonded over shared interests in sports, the arts, and human rights. The two began collaborating on research and soon married, equitably combining their names and signing their work Irène and Frédéric Joliot-Curie.

3. SHE AND HER HUSBAND WERE AN UNSTOPPABLE PAIR.

Black and white photo of Irène and Fréderic Joliot-Curie working side by side in their laboratory.
Bibliothèque Nationale de France, Wikimedia Commons // Public Domain

Their passion for exploration drove them ever onward into exciting new territory. A decade of experimentation yielded advances in several disciplines. They learned how the thyroid gland absorbs radioiodine and how the body metabolizes radioactive phosphates. They found ways to coax radioactive isotopes from ordinarily non-radioactive materials—a discovery that would eventually enable both nuclear power and atomic weaponry, and one that earned them the Nobel Prize in Chemistry in 1935.

4. THEY FOUGHT FOR JUSTICE AND PEACE.

The humanist principles that initially drew Irène and Frédéric together only deepened as they grew older. Both were proud members of the Socialist Party and the Comité de Vigilance des Intellectuels Antifascistes (Vigilance Committee of Anti-Fascist Intellectuals). They took great pains to keep atomic research out of Nazi hands, sealing and hiding their research as Germany occupied their country, Irène also served as undersecretary of state for scientific research of the Popular Front government.

5. SHE WAS NOT CONTENT WITH THE STATUS QUO.

Irène eventually scaled back her time in the lab to raise her children Hélène and Pierre. But she never slowed down, nor did she stop fighting for equality and freedom for all. Especially active in women’s rights groups, she became a member of the Comité National de l'Union des Femmes Françaises and the World Peace Council.

6. SHE WORKED HERSELF TO DEATH.

Irène’s extraordinary life was a mirror of her mother’s. Tragically, her death was, too. Years of watching radiation poisoning and cancer taking their toll on Marie never dissuaded Irène from her work. In 1956, dying of leukemia, she entered the Curie Hospital, where she followed her mother’s luminous footsteps into the great beyond.

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Live Smarter
You Can Now Order Food Through Facebook
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After a bit of controversy over its way of aggregating news feeds and some questionable content censoring policies, it’s nice to have Facebook roll out a feature everyone can agree on: allowing you to order food without leaving the social media site.

According to a press release, Facebook says that the company decided to begin offering food delivery options after realizing that many of its users come to the social media hub to rate and discuss local eateries. Rather than hop from Facebook to the restaurant or a delivery service, you’ll be able to stay within the app and select from a menu of food choices. Just click “Order Food” from the Explore menu on a desktop interface or under the “More” option on Android or iOS devices. There, you’ll be presented with options that will accept takeout or delivery orders, as well as businesses participating with services like Delivery.com or EatStreet.

If you need to sign up and create an account with Delivery.com or Jimmy John’s, for example, you can do that without leaving Facebook. The feature is expected to be available nationally, effective immediately.

[h/t Forbes]

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