A competition run by Government intelligence agency GCHQ to find the nation’s best young female codebreakers has opened again.

Schools from across south London, Kent and Surrey finished in the top 100 in last year’s inaugural CyberFirst Girls competition, including The Tiffin Girls’ School in fifth, Newstead Wood in 16th, Dartford Grammar School for Girls in 44th, Bromley High School in 64th and Nonsuch High School for Girls in 71st.

Now registration for the contest, run by the National Cyber Security Centre – part of GCHQ – has reopened for 2018.

Security experts have devised 100 challenges of varying difficulty for girls aged 12 to 13 to complete during the online phase. It will test their intellect and cyber skills as they decrypt a series of logic boxes and regular expression crosswords.

The top 10 scoring teams will then take part in a live head-to-head final in Manchester in March.

There is a global shortage of female cyber security staff but in 2017, 8,000 girls from across the country took part in the competition.

GCHQ Director Jeremy Fleming said: “I hope many girls will be inspired to enter – and perhaps take the prize!

“GCHQ is committed to protecting the digital homeland and making the UK the safest place to live online. We need the best and brightest people – girls and boys – with a passion for technology, who can deliver the nation’s cyber security.

“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.”

The competition is for girls in Year 8. They can enter in teams of up to four, along with a teacher who will act as a mentor and guardian.

This year’s winning school will receive a grand prize of £1,000 towards their school’s IT equipment, while each winner will take home individual prizes.