Can you crack these GCHQ challenges? Brain teasers released to launch CyberFirst Girls contest

The puzzles are below and the answers are on page 2

Can you crack these GCHQ challenges? Brain teasers released to launch CyberFirst Girls contest

Across the globe, we’re facing a shortage in the number of girls and women getting into STEM and cybersecurity.

According to figures in the 2017 Global Information Security Workforce Study (GISWS): Women in Cybersecurityparticipation by women increased by 40.9%, yet representation of women in cybersecurity roles is a paltry 11%. 

In an attempt to boost these numbers and encourage more girls to explore cyber-based skills, the National Cyber Security Centre (NCSC), which is part of GCHQ, has opened registration for the online phase of the 2018 CyberFirst Girls Competition. It’s open to girls in Year 8 in England and Wales, S2 in Scotland and Year 9 in Northern Ireland. The pupils can enter in teams of up to four, along with a teacher as a mentor and guardian.

As part of this online phase, NCSC and GCHQ experts have devised 100 challenges of varying difficulty. Entrants are tested on decryption techniques, crosswords and Morse Code. Around 8,000 girls took part in last year’s inaugural competition and this year’s top 10 scoring teams will be invited to take part in a live national head-to-head final in Manchester in March.

In addition, this year’s winning school will receive a prize of £1,000 towards school IT equipment, while each winner will take home individual prizes. Last year’s prize was taken by Lancaster Girls Grammar School.

“Too often, society limits girls in what they aspire to achieve. Our CyberFirst Girls Competition will give teams the opportunity to develop new skills, meet new people and gain an exciting insight into the world of national security,” said Jeremy Fleming, director of GCHQ. 

Scroll to the bottom of this article to learn more about applying. You can find the answers to the challenges on page 2.

Challenge 1: Domino Logic

  • We can use dominos to create logic gates, you just have to work out how the dominoes will fall. 
  • Pushing a domino input represents a 1 on a logic gate. Leaving dominos standing represents a 0.  
  • Can you work out what would happen when you push the dominoes and use it to complete the logic tables below?


Challenge 2: Can you work out what the sentence says?

This gets redrah ot wvguwv kkwdfm 647 892546 848858234 8112 38313538333238373334323132383231323834313638313538343834383838333534 …– –… …– -…. …– ….- …– —.. …– -…. …– —.. …– ….- …– …– …– –… …– …– …– ….- …– ….- …– —.. …– ….. …– —.. …– ..— …– —.. …– …– …– ….. …– ….- …– ….- …– ….. …– …– …– —.. …– .—- …– —.. …– —.. …– ….- …– -…. …– —.. …– ….- …– …– …– ….- …– —.. …– ….. …– —.. …– ..—

Challenge 3: ‘Rotters’

Q. 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? 

Challenge 4

Challenge 4: Anagram Crossword 

We hope to inspire the next generation of cyberists, can you find some inspirational tech innovators from our clues (and solve the anagram hidden in the grey boxes)?



2D and 4D 1906 (5,6) 

3D and 5D 1957 (6, 6) 

7D and 6A 1623 (6, 6) 

8D and 7A 1949 (5, 4) 

11D and 9A 1815 (3, 8) 

12A and 1D 1914 (4,6) 

13A and 10A 1912 (4, 6)

Challenge 5: Can you crack the NCSC’s regex crossword?

Can you crack this cryptic crossword? Instead of a word or phrase, each clue is a regular expression (or a ‘regex’). To complete the puzzle, find the letter matching both the horizontal and vertical regex for each square.

Confused? Here are a few pointers to get you started:

  • Characters in square brackets [SUCHASTHIS] are ‘character classes‘. They signify any of the characters in the box.
  • A caret/hat (^) inside a character class [^LIKETHIS] inverts the match. (Must NOT be any of the characters in the box).
  • Numbers in curly brackets (like {2}) means that the character/pattern immediately before it must occur this number of times. (So A{3} literally means AAA).


If this focus on women triggers any sexist remarks about positive discrimination, the NCSC does offer free CyberFirst courses for 11 to 17-year-old males and females. This contest is aimed specifically at female pupils due to the shortage, opening out to a huge swathe of talent in the UK that are potentially missing out on a career they could excel in. 

How to apply for CyberFirst Girls 2018

  • Team guardians can register their teams from 16 January here.
  • The online competition starts on 29 January and closes on 5 February 2018.

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