Knowledge check

Stream ciphers & ChaCha20-Poly1305

10 questions testing what you just read — no login, no tracking, just immediate feedback.

Question 1 of 10

What operation does a stream cipher like ChaCha20 use to combine its keystream with the plaintext?

Question 2 of 10

Why doesn't ChaCha20 rely on table lookups the way some AES software implementations do?

Question 3 of 10

Paired with Poly1305, ChaCha20 becomes an AEAD construction functionally equivalent to which AES mode?

Question 4 of 10

What's the fundamental difference between a block cipher like AES and a stream cipher like ChaCha20?

Question 5 of 10

Who designed ChaCha20?

Question 6 of 10

How many rounds of ARX mixing does ChaCha20 use to generate a keystream block?

Question 7 of 10

What does ChaCha20 alone, without Poly1305, actually provide?

Question 8 of 10

Which VPN protocol uses ChaCha20-Poly1305 as its default cipher?

Question 9 of 10

Why is ChaCha20-Poly1305 especially popular on mobile and low-power devices?

Question 10 of 10

What three inputs seed ChaCha20's internal state before it generates a keystream block?

0 / 10 answered