Exercises

Every exercise from the courses, in one place. Search for a specific one, filter by subject, or let chance pick one for you.

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Flash questionsShort drills on core skills, as cards to project or print.See the series

1120 exercises

AES, the Encryption Standard

Cryptographie – Symétrique4 exercises

Confusion and diffusion in AES

Short answerAdvanced

The number of rounds of AES-256

Why AES-128 remains secure

Open answerAdvanced

The importance of the avalanche effect

Hash functions: construction and attacks

Cryptographie – Intégrité4 exercises

Recovering a password

Short answerAdvanced

The size of SHA-256

The cost of a collision

Open answerAdvanced

Why ban MD5

MAC and HMAC: authenticating messages

Cryptographie – Intégrité4 exercises

What a MAC adds to hashing

Short answerAdvanced

The missing property

HMAC rather than Hash(key || message)

Open answerAdvanced

Timing attack on comparison

Elliptic curve cryptography

Cryptographie – Clé publique4 exercises

The difficulty of the ECDLP

Short answerAdvanced

The equation of an elliptic curve

The advantage of elliptic curves

Open answerAdvanced

The ECDSA nonce

Shamir's Secret Sharing

Cryptographie – Protocoles4 exercises

The number of shares needed

Short answerAdvanced

The threshold of a parabola

What k-1 shares guarantee

Open answerAdvanced

Why modular arithmetic

Zero-Knowledge Proofs

Cryptographie – Protocoles4 exercises

Identifying the right property

Short answerAdvanced

The probability after ten rounds

A real use of zero-knowledge proofs

Open answerAdvanced

Repetition and soundness