Create A Strong Passcode

You reveal the digits of your code by fingerprint smudges on your smartphone screen.

You can make the passcode you used to unlock your device stronger with a few simple tricks. It turns out that repeating one or two digits in your 6 or 7-digit passcode makes it much stronger. Be sure you use at least six digits. 

Here are the details.

A 6-digit passcode is strongest when it contains only 5 distinct digits.

	Distinct digits	Possibilities
	6	720
	5	1800
	4	1560
	3	540
	2	62
	1	1

 

 

 

 

 

 

For a 7-digit passcode, use only 5 different digits to get the strongest code. 

	Distinct digits	Possibilities
	7	5040
	6	15120
	5	16800
	4	8400
	3	1806
	2	126
	1	1

 

 

 

 

 

 

 

Note: The 7-digit passcode is over 9 times as strong as the 6-digit code.

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The Mathematical Reason Your Passcode Should Repeat A Digit – YouTube video