The Perse School

Codebreaking success for Perse students

A Perse Upper School student cracked a complex Trifid Cypher to come in the top 10 of the high-profile National Cipher Challenge.

Pratap Singh, Year 9, came seventh out of 1600 teams – of which only 30 completed every level.  Along with the satisfaction and prestige he wins a Raspberry Pi computer and a Netcraft Rucksack. Several Perse teams took part, with Thomas Read also placing in the top 100.

Pratap said:

“The final and hardest challenge was a very difficult cypher that required real cryptanalysis rather than a brute-force or simplistic approach. For challenge 8A, a simpler cipher, I was able to use programs that I had previously written for the earlier challenges to solve it in 2 minutes and 52 seconds.  However, on challenge 8B, I worked almost continuously for the first 24 hours and for several hours every day for the next week, trying various things.  

I learnt a lot in solving the challenge, including quite a lot of programming which I used for solving 8B.  I made use of the highly useful data structure set, which acted just like a mathematical set.”

Pratap studied programming fundamentals at the The Perse. The National Cypher Challenge is organised by the University of Southampton and this year’s competition ran for two months, with codes of increasing difficulty being issued periodically for teams to crack.

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