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CryptoHack

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 intrepidbird 7445
#2 d3codex 3995
#3 nafizmuhammad 3485
#4 jorcev 2990
#5 GekySan 2815
Recent Solves
Encoding Challenge OZ
Oh SNAP sem1tonos
Quadratic Residues juno99
Modular Square Root kriska
Modular Binomials kriska
Recent Solutions
Megalomaniac 1 goreil 0
Megalomaniac 2 ConnorM 0
Megalomaniac 1 ConnorM 0
Favourite byte xv1 0
Greatest Common Divisor xv1 0

Level Up

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