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A fun, free platform for learning modern cryptography

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Learn By Doing

Learn about modern cryptography by solving a series of interactive puzzles and challenges. Get to know the ciphers and protocols that secure the digital world by breaking them.

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Level Up

Earn points by solving challenges. Finish categories to earn trophies and gain levels to track your progress. Can you reach the top of the scoreboard?

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Fresh Challenges

We are constantly creating new challenges to keep your crypto knowledge up to date. Expect exciting brainteasers and whole new categories as the site continues to grow.

New Challenges
Blind (ECSC 2023 (Norway)) CTF Archive 0
WOTS Up (ECSC 2023 (Norway)) CTF Archive 0
Irish flan (ECSC 2023 (Norway)) CTF Archive 0
WOTS Up 2 (ECSC 2023 (Norway)) CTF Archive 0
Twist and shout (ECSC 2023 (Norway)) CTF Archive 0
Weekly Top Users
#1 sravani 2970
#2 Cypha69 2875
#3 Mehul_007 2630
#4 jebil123 2615
#5 whale120 2415
Recent Solves
CERTainly not blanch1234
Bean Counter Tt123N
Endless Emails Dream3rx
MD0 Ivan_Kotov
XOR Properties xalvakostas
Recent Solutions
Passwords as Keys Ubertech 0
Broken RSA zenobia 1
Diffie-Hellman Starter 3 3b0_0d 0
Diffie-Hellman Starter 2 3b0_0d 0
Salty 3b0_0d 0

Level Up

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