Are you smart enough to qualify as a British spy? Take this challenge to find out!
There are puzzles that test your intelligence, and there are puzzles that test your skills. But none have required extreme, sleuth-worthy superpowers—until now.
BBC Radio 4’s “Today” recently broadcasted a mind-boggling riddle that is sure to leave you scratching your head. It was created by the British National Cyber Security Centre (NCSC), an organization that detects and fights against computer security threats. (Can you solve this tricky numbers riddle in less than 60 seconds?)
Hoping to recruit future spies, the NCSC posed this question for listeners: “Thirteen rotters stole my answer and they ROTated it by 4 and then ROTated it by 10 and all I have left is Uccr ziqy hc ozz QmpsfTwfgh Uwfzg! Can you help me get my answer back?”
Unless you’re already a secret agent in disguise, you might need a hint to decode this tricky riddle. According to Curiosity, this is an example of a “Caesar cipher,” which scrambles a message by moving each letter a certain number of positions down the alphabet. For example, if all letters were shifted left by 3, D would become A, E would become B, etc. (Here are 26 fascinating facts about every letter in the English alphabet!)
What’s more, the phrase “thirteen rotters” refers to “ROT13,” a cipher that replaces each letter with a letter that comes 13 letters after it. (Piece of cake? An MIT professor called this the “hardest logic puzzle ever.” Can you solve it?)
To decode the riddle, Curiosity recommends writing down the entire alphabet before you begin. Then, start with the first letter in the message (U) and count four letters back; you should get Q. That covers the part of the riddle that says, “they ROTated it by 4.”
Now, the puzzle says, they “ROTated it by 10.” Count back 10 more letters, and you get G. That is the first letter of the solution. Repeat this process for every letter in the message to unscramble the code.
What did you get? If your final answer reads, “Good luck to all CyberFirst girls!,” congratulations—you solved the riddle. One application for the British secret intelligence, coming right up! (Brush up on your secret service savvy by watching the 12 greatest spy movies of all time!)
Speaking of British spies, how well do you know your 007? Check out our ultimate ranking of every James Bond film—from worst to best!
Originally published as If You Can Solve This Puzzle, You Could Qualify to Be a British Spy on ReadersDigest.com.