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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
What a Curve! (Breizh CTF) CTF Archive 0
GLP420 (HackTM CTF) CTF Archive 0
unrandom DSA (HackTM CTF) CTF Archive 0
kaitenzushi (HackTM CTF) CTF Archive 0
d-phi-enc (HackTM CTF) CTF Archive 0
Weekly Top Users
#1 Mikbrosim 2655
#2 Nissen 2600
#3 zukash 2280
#4 jsack 2125
#5 shalaamum 2050
Recent Solves
Legendre Symbol hackerBeb
Bytes and Big Integers timgluz
Resisting Bruteforce 2SthN1ght
Transparency jsack
Passwords as Keys HauPham310
Recent Solutions
Extended GCD thebug 0
Greatest Common Divisor thebug 0
Jack's Birthday Hash cruzzer 0
Encoding Challenge skriptr 0
RSA Starter 6 skriptr 0

Level Up

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