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

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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Bleat Along to Classic Holiday Tunes With This Goat Christmas Album
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Feeling a little Grinchy this month? The Sweden branch of ActionAid, an international charity dedicated to fighting global poverty, wants to goat—errr ... goad—you into the Christmas spirit with their animal-focused holiday album: All I Want for Christmas is a Goat.

Fittingly, it features the shriek-filled vocal stylings of a group of festive farm animals bleating out classics like “Jingle Bells,” “Rudolph the Red-Nosed Reindeer,” and “O Come All Ye Faithful.” The recording may sound like a silly novelty release, but there's a serious cause behind it: It’s intended to remind listeners how the animals benefit impoverished communities. Goats can live in arid nations that are too dry for farming, and they provide their owners with milk and wool. In fact, the only thing they can't seem to do is, well, sing. 

You can purchase All I Want for Christmas is a Goat on iTunes and Spotify, or listen to a few songs from its eight-track selection below.

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What Are the 12 Days of Christmas?
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Everyone knows to expect a partridge in a pear tree from your true love on the first day of Christmas ... But when is the first day of Christmas?

You'd think that the 12 days of Christmas would lead up to the big day—that's how countdowns work, as any year-end list would illustrate—but in Western Christianity, "Christmas" actually begins on December 25th and ends on January 5th. According to liturgy, the 12 days signify the time in between the birth of Christ and the night before Epiphany, which is the day the Magi visited bearing gifts. This is also called "Twelfth Night." (Epiphany is marked in most Western Christian traditions as happening on January 6th, and in some countries, the 12 days begin on December 26th.)

As for the ubiquitous song, it is said to be French in origin and was first printed in England in 1780. Rumors spread that it was a coded guide for Catholics who had to study their faith in secret in 16th-century England when Catholicism was against the law. According to the Christian Resource Institute, the legend is that "The 'true love' mentioned in the song is not an earthly suitor, but refers to God Himself. The 'me' who receives the presents refers to every baptized person who is part of the Christian Faith. Each of the 'days' represents some aspect of the Christian Faith that was important for children to learn."

In debunking that story, Snopes excerpted a 1998 email that lists what each object in the song supposedly symbolizes:

2 Turtle Doves = the Old and New Testaments
3 French Hens = Faith, Hope and Charity, the Theological Virtues
4 Calling Birds = the Four Gospels and/or the Four Evangelists
5 Golden Rings = the first Five Books of the Old Testament, the "Pentateuch", which gives the history of man's fall from grace.
6 Geese A-laying = the six days of creation
7 Swans A-swimming = the seven gifts of the Holy Spirit, the seven sacraments
8 Maids A-milking = the eight beatitudes
9 Ladies Dancing = the nine Fruits of the Holy Spirit
10 Lords A-leaping = the ten commandments
11 Pipers Piping = the eleven faithful apostles
12 Drummers Drumming = the twelve points of doctrine in the Apostle's Creed

There is pretty much no historical evidence pointing to the song's secret history, although the arguments for the legend are compelling. In all likelihood, the song's "code" was invented retroactively.

Hidden meaning or not, one thing is definitely certain: You have "The Twelve Days of Christmas" stuck in your head right now.

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