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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
RSA or HMAC? Part 2 Crypto on the Web 100
Roll your Own Mathematics 125
Dancing Queen Symmetric Ciphers 120
SSH Keys General 35
LFSR Destroyer Misc 250
Weekly Top Users
#1 Kkameleon 3750
#2 adonkey 1950
#3 EnClaimWas 1225
#4 limeeattack 1100
#5 k3w1k0d3r 1060
Recent Solves
Factoring gaLaxy_
RSA Starter 6 gaLaxy_
RSA Starter 5 gaLaxy_
RSA Starter 4 gaLaxy_
RSA Starter 3 gaLaxy_
Recent Solutions
Modular Inverting whoam1ns 0
Extended GCD whoam1ns 0
Modular Arithmetic 1 whoam1ns 0
Modular Arithmetic 2 whoam1ns 0
Greatest Common Divisor whoam1ns 0

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