Forget Your Password: Typing Rhythm and Computer Security

Patricia Loring, a research associate at Carnegie Mellon University, presses tiny blue dots on my fingers and the back of my hand. She tells me to adjust the keyboard as she maneuvers three webcams. On a monitor, I see a split screen, displaying images of my hands and posture (which is terrible). The blue stickers make it easier for the cameras to record my finger movements.

She tells me to look at a picture, Norman Rockwell’s Girl with Black Eye, and compose an email about it. I must type uninterrupted until I fill a text box, which probably holds about 400 words. I cannot talk and she tells me to not worry about my grammar or errors.

I am typing as a participant in a study led by Roy Maxion, a PhD research professor of computer science at CMU. He thinks that typing rhythms and the timing of keystrokes might be able to be used as a biometric, adding another level of security to computers. Keystroke biometrics could also be used in criminal cases.

Computer scientists have known about keystroke biometrics for years, but the research has been conducted in a haphazard way. Maxion is taking a fresh look. If the theories are correct, each person’s typing rhythm is different. Nobody could mimic another person's rhythm.


Since the 1800s and the rise of the telegraph, there has been evidence that each individual possesses a unique typing style.

“The original idea came from the 1800s with the telegraph—one person could tell who was on the other end of the line because of the rhythm of the dots and dashes,” Maxion says.

During World War II, telegraph operators transmitted covert messages using Morse code. While each side used encrypted messages, the British still listened to the German cables and soon discovered they could identify certain telegraph operators by their typing rhythms, what telegraph operators (and ham radio aficionados) refer to as an operator’s fist. After realizing what operator was attached to what battalion, the British could track the German troop movement—even though they didn’t understand the messages.

In the 1970s, a researcher with the Rand Corporation produced a small study on keystroke rhythms. The researcher looked at six different typists, noticing each one had a different tempo and he could identify each by their typing beat. In the following decades, researchers replicated the studies, but sometimes there were too many variables. For example, some researchers ask participants to log into a site from their home computer to type, but this presents a problem. “Everyone has a different keyboard so you don’t know if the keyboard influences typing,” Maxion explains. (The keyboard in Maxion’s lab felt tight, which probably slowed my typing.)

Typing Tests

Maxion conducts a variety of different experiments to determine typing rhythm. In one set, he asked a number of subjects to come to the lab and learn a password, which is 10 characters long. At first, all the subjects struggle to learn the string of characters, but soon they do, a pattern emerges—each person’s beat is different. Of 28 people typing the 10-character passwords, Maxion can identify typists with 99.97 percent accuracy. Even though this is an incredibly low error rate, Maxion feels he cannot say with certainty that everyone has a unique typing style.

“Our own work would suggest that keystrokes are unique,” Maxion says. But he adds a caveat: “The more people, the more likely that two people’s typing rhythms will be too similar to tell them apart.”

By including an individual’s typing rhythm as an additional layer of protection, it makes it almost impossible for an imposter to access a computer from the keyboard login. “If you knew my password, you could access my computer,” he says. But it is exceedingly difficult (if not impossible) to mimic another’s typing cadence.

In the lab, as I typed an email to my mother about my fictitious redheaded child who'd gotten into a fight because a classmate called her a ginger, I was helping Maxion and Loring gather data for a different experiment—to see if a typist can be identified by her unique style as she types throughout the day, offering continuous re-authentication. In some high security jobs, it is important to prompt the user to re-identify herself to prevent imposters from accessing information or changing sensitive documents. This might also prove useful for prosecutors in white-collar crimes, where documents may have been altered.

After I finish weaving a tale about my imaginary offspring, Loring asks me to place my right hand on what looks like grid paper used in high school math classes. She positions my hands, spreading my fingers wider, asking me to keep my wrist straight. She snaps a picture. On to the left. My hands will join pictures of hundreds of others.

“Even the size of hands can influence keystrokes,” Maxion explains.

Loring tells me I'm a well-behaved typist—I show the hallmarks of someone who learned to type in a class. My typing teacher would be pleased.

For more information about Maxion’s research, check out his publications at

9 Things You Should Keep in Mind Around Someone Observing Ramadan

To mark the ninth (and most holy) month in the Islamic calendar, Muslims around the world observe Ramadan. Often compared to Lent in Christianity and Yom Kippur in Judaism, Ramadan is all about restraint. For one month, Muslims observing Ramadan fast during the day and then feast at night.

By abstaining from food and water (as well as sex, smoking, fighting, etc.) during daylight, Muslims strive to practice discipline, instill gratitude for what they have, and draw closer to Allah. To be respectful and not annoy observers, here are nine things you should never say or do to someone observing Ramadan.


A traditional iftar meal.
A traditional iftar meal.

Although it might be tempting to joke about Ramadan being a good excuse to lose weight, it is a time for spiritual reflection and is a serious matter. Observers undertake the challenge of fasting for religious and spiritual reasons rather than aesthetic ones. And, once the sun sets each night, many Muslims prepare a hearty iftar (the meal that breaks the fast) of dates, curries, rice dishes, and other delicious foods. The suhoor (the pre-dawn meal) is often fresh fruit, bread, cheese, and dishes that are high in fiber and complex carbohydrates. So the idea of a cleanse is pretty far from their minds.


An Indian Muslim student recites from the Quran in a classroom during the holy month of Ramadan.

There are approximately 1.8 billion Muslims around the world, but not all of them observe Ramadan the same way. Although most observant Muslims fast for Ramadan, don't assume that every Muslim you meet has the same methods, traditions, and attitudes towards fasting. For some, Ramadan is more about prayer, reading the Qur'an, and performing acts of charity than merely about forgoing food and drink. And for those who may be exempted from the daily fasting, such as pregnant or nursing women, the elderly, or those with various health conditions, they might not appreciate the reminder from nosey busy-bodies that they aren't participating in the traditional way.


A sign which reads
A sign which reads "Ramadan Kareem" in Arabic is seen pictured in front of the Burj Khalifa in downtown Dubai.

Rather than wishing someone a happy Ramadan, being more thoughtful with your choice of words can show that you understand and respect the sanctity of their holy month. Saying "Ramadan Mubarak" or "Ramadan Kareem" are the traditional ways to impart warm wishes—they both convey the generosity and blessings associated with the month. The actual party comes after Ramadan, when Muslims celebrate Eid al-Fitr, an up to three-day festival that involves plenty of food, time with family, and gifts.


Muslim woman saying no to an apple.

Even if the idea of not eating or drinking all day might be unfathomable to you, don't push food onto anyone observing Ramadan. While fasting all day for a month can cause mild fatigue, dehydration, and dizziness, don't try to convince participating Muslims to eat or drink something—they are fully aware of any side effects they may feel throughout the day. Instead, be respectful of their decision to fast and offer to lend a hand with something like chores, errands, or anything unrelated to food.


Dates and a glass of water.

Muslims who observe Ramadan don't sip any liquids during daytime. No water, coffee, tea, or juice. Zilch. Going without water is even harder than going without food, so be aware of the struggle and accept it. It's all part of the sacrifice and self-discipline inherent in Ramadan.


Pregnant woman doing yoga.

Some Muslims choose not to fast during Ramadan for medical or other personal reasons, and they may not appreciate being badgered with questions about why they may be eating or drinking rather than fasting. Children and the elderly generally don't fast all day, and people who are sick are exempt from fasting. Other conditions that preclude fasting during Ramadan are pregnancy, breastfeeding, and menstruation (although, if possible, people generally make up the days later).


Woman running on the beach.

Eschewing food and drink for hours at a time can cause lethargy, so be aware that Muslims observing Ramadan may be more tired than usual. Your Muslim friends and coworkers don't stop working for an entire month, but they may tweak their schedules to allow for more rest. They may also stay indoors more (to prevent overheating) and avoid unnecessary physical activity to conserve energy. So, don't be offended if they aren't down for a pick-up game of basketball or soccer. We can't all be elite athletes.


Family playing in the park.

One of the worst things you can do to someone on a new diet is to obsess over all the cheeseburgers, pizza, and cupcakes they can't have. Similarly, most Muslims observing Ramadan don't want to have in-depth conversations about all the food and beverages they're avoiding. So, be mindful that you don't become the constant reminder of how many hours are left until sundown—just as you shouldn't joke about weight loss, you shouldn't call attention to any hunger pangs.


Coworkers discussing a project on couches.

Although it's nice to avoid talking about food in front of a fasting Muslim, don't be afraid to eat your own food as you normally would. Seeing other people eating and drinking isn't offensive—Muslims believe that Ramadan is all about sacrifice and self-discipline, and they're aware that not everyone participates. However, perhaps try to avoid scheduling lunch meetings or afternoon barbecues with your Muslim colleagues and friends. Any of those can surely wait until after Ramadan ends.

Timm Schamberger, AFP/Getty Images
Disney Princesses in Order Minefield
Timm Schamberger, AFP/Getty Images
Timm Schamberger, AFP/Getty Images


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