You might be giving away valuable hints about your PIN and password merely by the way you hold your phone.

Researchers at Britain's Newcastle University found it's possible to guess a four-digit PIN just by monitoring the motion sensors found inside nearly all smartphones.

The group's report, published this week in the International Journal of Information Security, claims the slight ways you move the device when you type a password—including tilting it to change the screen's orientation—can give away which characters are in the password, giving hackers valuable hints to eventually guess what you're typing.

Motion sensors in phones are so sophisticated that even the slightest movements of the wrist are detected, giving hints as to which numbers are included in a PIN, for example.

Lead researcher Dr. Maryam Mehrnezhad said hackers are able to easily monitor your phone's motion sensors because apps and websites don't need your permission to access most of them.

"More worrying, on some browsers, we found that if you open a page on your phone or tablet which hosts one of these malicious code and then open, for example, your online banking account without closing the previous tab, they can spy on every personal detail you enter," Mehrnezhad said.

The report states that by simply analyzing motion-sensor data, it is possible to guess a four-digit PIN, with 70-percent accuracy, on the first try. They said by the fifth guess, the PIN can be guessed with 100-percent accuracy.

Clint Davis covers entertainment and trending news topics for the Scripps National Desk. Follow him on Twitter @MrClintDavis.