Cryptography
Beginner
Crypto Primitives & Pitfalls
XOR, hashing, HMAC, symmetric vs asymmetric, AEAD. The 'do not roll your own' rules.
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- 1Quiz+90 XP
Crypto 101: Primitives, Pitfalls & Best Practices
This quiz validates your understanding of fundamental cryptographic concepts, common implementation pitfalls, and when to use specific primitives. You must demonstrate knowledge of XOR operations, hashing, MACs, encryption modes, and the critical 'don't roll your own crypto' principle.
open quiz - Hands-on Labeasy+25 XP
Weak XOR Crypto
A ciphertext is base64-encoded and XOR-encrypted with a single ASCII byte. Recover the plaintext.
complete the module above first - Hands-on Labeasy+30 XP
MD5 Collision Drill
Find two different inputs whose MD5 hashes collide. (Hint: prefix-collision attack is well-known.)
complete the module above first - Hands-on Labmedium+45 XP
Hash Length Extension
A naive MAC = MD5(secret || message) is forgeable via length extension. Forge `admin=true`.
complete the module above first
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