Knowledge check
12 questions testing what you just read — no login, no tracking, just immediate feedback.
Why does the penguin's outline survive AES-ECB encryption?
Why is a scheme that always encrypts the same message to the same ciphertext not IND-CPA secure?
What did the BEAST attack exploit in TLS 1.0's use of CBC?
A message is exactly 16 bytes long. How does PKCS#7 pad it for AES-CBC?
Two messages were encrypted with AES-CTR under the same key and nonce. What does XORing the two ciphertexts give an attacker?
Which way of combining a cipher with a separate MAC did Bellare and Namprempre show to be secure in general?
In an AEAD, what is the 'associated data'?
With random 96-bit nonces, roughly how many messages does NIST SP 800-38D allow under one AES-GCM key?
Why is ChaCha20-Poly1305 often preferred over AES-GCM on devices without AES hardware instructions?
What does a nonce-misuse-resistant AEAD such as AES-GCM-SIV leak if a nonce is accidentally reused?
Which NIST format-preserving encryption mode is still specified in the 2025 draft revision of SP 800-38G?
FF1 encrypts the same card number to the same token every time. What does that cost?