You wake up and grab your phone off the nightstand, eyes still bleary from sleep. As the pattern lock screen pops up, you mindlessly draw your familiar pattern without thought. It’s quick, easy, and lets you get right to scrolling through notifications. But how secure is that pattern keeping prying eyes out?

Most People Use Common Shapes or Letters

Let’s face it: we’re creatures of habit. When setting up a pattern lock, we naturally gravitate towards what’s familiar. It’s a no-brainer to connect the dots to form letters like b, C, d, D, e, g, G, L, M, N, O, P, R, S, U, W, and Z, or numbers like 2, 5, 6, 7, and 9. Even shapes like a square or a triangle seem like good choices. They’re easy to remember, and let’s be honest, who wants to spend time recalling a complex pattern just to check a notification?

However, the problem is, if it’s easy for you, it’s easy for someone else to guess, too. Especially if others know you well enough to predict you’d choose letters from your name or your birthday number. Moreover, according to a study reported by Arstechnica, most people tend to create patterns starting from the top-left corner and moving from left to right or top to bottom. This makes guessing even easier.

So, if your pattern lock is similar to the ones in the image above, it might be time for a change. If your phone ever falls into the wrong hands, those are the patterns they’ll likely try first. So, how about switching things up a bit? Opt for something a tad more complex—think overlaps, slashes, or movements that double back over areas you’ve already traced. It doesn’t have to be a brain teaser, but the more unique and intricate it is, the better your odds of keeping your pattern lock a secret. Just a little food for thought for the next time you’re setting up a pattern lock.

Smudges on Your Screen Can Reveal Your Pattern Lock

Every time you swipe your finger across the screen to unlock your phone, you leave behind a trail of oily residue or “smudges.” Normally, they’re just a nuisance that makes your screen look dirty. But in the wrong hands, these smudges can reveal your unlock pattern.

Picture this: you leave your phone unattended at a café for a moment. A savvy person picks it up, angles it towards a light, and voilà—your finger smudges become visible, revealing your unlock pattern. This is what is known as a “smudge attack.”

According to a study [PDF] by researchers from the University of Pennsylvania, a smudge attack can successfully identify lock patterns in 68% of cases under ideal conditions. The study also found that more complex patterns with more turns and hooks actually left greater contrast and were sometimes easier to recognize than simpler patterns in smudge photographs, which is quite surprising.

There Are Far Fewer Pattern Combinations

You can start your pattern from any of the nine dots in the 3×3 grid—which is the typical size. But once you’ve chosen your starting point, your options for the next point become limited. You can’t repeat a dot, and some dots can’t be reached unless you’ve passed through others first.

So, how many unique patterns can you actually create? Considering all these rules, mathematical calculations determine that just under 400,000 possible pattern combinations exist. That might sound like a lot, but compare it to a 6-digit PIN with one million possible combinations or a 6-character password consisting of uppercase letters and numbers, whose combination is significantly larger, possibly reaching the billions.

The relatively small pattern space means an attacker could use software to check all possible patterns to unlock your phone systematically. That can be done with PINs and passwords, too, but it’s not as easy.

Other People Can Easily Spy on Your Pattern

Imagine you’re in a public place, casually unlocking your phone. Little do you know, there’s someone nearby stealing a glance at your screen. With a quick look over your shoulder, they can observe and memorize the pattern you drew. This sneaky tactic is known as a “shoulder-surfing attack” (but is it really an attack?!).

The beauty and curse of pattern locks lie in their simplicity and visual nature. They’re easy to remember, even from a distance or with just a fleeting look. So, anyone who can catch a glimpse of your screen when you unlock your phone could potentially learn your pattern.

But don’t worry; there’s a simple trick to make you less vulnerable to this issue in public areas. Just use your device at an angle that shields your screen from prying eyes.

There Are Better Alternatives to Pattern Locks

Pattern locks might seem like an easy option, but they don’t offer much protection. If you really want to lock down your Android, there are way better alternatives.

For starters, setting a PIN or password on your phone works well. Sure, coming up with a long string of numbers, letters, and symbols can feel like a pain, but that random mess also makes it crazy hard for anyone else to crack your code. If remembering a complex password sounds like too much work, you can go for the biometric options if your phone has the hardware. Just let your phone scan your face or finger, and boom—unlocked.

And don’t forget all the extra security settings you can enable, like Lockdown Mode, Smart Lock, and SIM card lock to keep the bad guys out. The goal here is to keep your phone locked up tight. Those pattern swipes might be cute but won’t stop a determined snooper. Consider other phone lock alternatives, and your phone and personal data will thank you.