Use your 4 digit combination lock correctly

The TSA approved luggage locks are useless.  Now that all the master keys are available for sale online or 3D printed at home you should really toss them.  Its better not to use any lock at all then to use one that only offers a false sense of security. 

A better solution is to use an old fashion combination lock.  I recommend the 4 digit ones.  There are many of them on Amazon but this lock is under $3.50 and so is this one.  This is half the cost of a typical TSA lock.

So why use a 4 digit combination lock?

The 4 digits theoretically gives you 10,000 possible code combinations; from 0000 to 9999.  This assumes it will take a long time to make 10,000 guesses thus offering some level of security.  Its a deterrence.

I say "theoretically" because most people pick really horrible passcodes so the level of protection is far less then what is possible.  Lets go over some really bad ones then I offer my practical solutions.

Some bad passcodes you should avoid.

1) Example: 0000, 1111, 2222, etc.

The 4 zeros are actually the default passcode for these kind of locks.  If you have used Bluetooth devices before it's the same passcode for pairing.  By setting your code to just a single digit you have effectively reduced your lock's protection from a 1 in 10,000 ( ie 1:10000) chance down to 1 in 10 (ie 1:10).  It would be better to not use any lock if you do this.

2) Example: 0123, 1234, 2345, etc.

If you try this strategy of sequential numbers you are no better off.  Again you've reduced the odds of guessing your passcode from 1:10000 down to 1:10.  How?  Here are all the possibilities.

 0123 1234 2345 3456 4567
 5678 6789 7890 8901 9012

3) Example: 0246, 2468, 4680, etc.

If your strategy was to use just even numbers then you made it even worst.  Now its just 1:5 chances of guessing your passcode.  Save your money and don't buy a lock.  Here are all the possibilities

0246 2468 4680 6802 8024

By the way, this also applies to odd sequential numbers.

1357 3579 5791 7913 9135

4) Example: 1995, 2000, 2004, 2017 etc.

I've seen a lot of people use years for their passcode possibly because it's in a 4 digit format they see often in daily life.  This too is a bad strategy.  At best your odds are 1:400 if you are using years between 19xx and 20xx.   The first 2 digits are significantly constrained. 

5) Example: 0704, 1031, 1225, etc.

I've also seen people use the month and day.  This strategy reduces your chances down to 1:800 as you've constrained the first and third digit.  While this is better then using years please avoid doing this.  Note, this possibility is less then a 3 digit lock which is 1:1000.

6) Example: 1478, 2580, 3698

These looks pretty good, right?  Look carefully.  You are just going down the keypad.  Specifically you are going down and right, straight down and down and left respectfully.  I've read a lot of people also use this to lock their phones.  You'll have to assume someone will try this.

7) Example: last 4 digits of your cell phone

This is especially bad if you travel.  Most hotel now ask for you cell phone number at check-in so they could reach you for emergencies or let you know your room is ready.

So how do you pick a good passcode?

It really simple; pick something you know, will remember or could easily look up.   For example; 4821 is a good choice.   If you have lived in the Virginia Beach area you notice that this is the building number of the local Wal-Mart.  Also, since you know its Wal-Mart you can always Google this and get the right combo if you ever forget it.


I should note, please do not use your own street numbers if they are 4 digits.  Use something the hotel staff would not know; like your cousin's home or your church.
 
You can also use the last 4 digits of a credit card.  Of course, use the numbers off a card that you won't be handing over for check-in.  Maybe a backup credit card.  The added benefit is that the card could serve as a reminder in case you forget the combination.
  
-spud