Cryptography Quiz

Q1. ECB mode is unsafe for structured data because:

Identical plaintext blocks always produce identical ciphertext blocks It is too slow It needs a huge key It cannot handle binary

Q2. Encoding such as Base64 differs from encryption because encoding:

Only works on binary Uses a weaker key Requires no key and provides no confidentiality Is slower

Q3. RSA's security relies on the difficulty of:

Base64 decoding XOR Sorting numbers Factoring large integers

Q4. The main argument for post-quantum algorithms is that:

A sufficiently large quantum computer would break RSA and ECC Current keys are too short AES is already broken Hashes are reversible

Q5. Using a general-purpose PRNG rather than a cryptographic one for tokens is unsafe because:

It is slower Its output can be predicted once enough values are observed It produces shorter values It cannot produce integers

Q6. Symmetric encryption differs from asymmetric encryption because it:

Only works on text Uses the same key to encrypt and decrypt Uses no key at all Cannot be broken

Q7. A message authentication code (MAC) provides:

Confidentiality only Compression Integrity and authenticity of a message Key exchange

Q8. AES-GCM is described as authenticated encryption because it:

Uses a longer key Requires a certificate Provides both confidentiality and integrity Runs in hardware

Q9. Preimage resistance means it is infeasible to:

Compute the hash quickly Find any input that hashes to a given digest Find two colliding inputs Extend a hash

Q10. A hash function is described as:

A reversible encryption method A firewall rule A network protocol An irreversible mathematical transformation of information

Q11. In TLS, asymmetric cryptography is used mainly to:

Encrypt the whole session Verify the MAC address Compress data Authenticate the server and agree a symmetric session key

Q12. Forward secrecy means that compromising the server's long-term key:

Disables TLS 1.3 Does not reveal the content of past recorded sessions Breaks all future sessions Breaks the certificate chain

Q13. Symmetric cryptography uses:

Two unrelated public keys Only a hash No key A single key for encryption and decryption

Q14. bcrypt, scrypt and Argon2 are preferred for passwords because they are:

Faster than SHA-256 Standardised by RSA Deliberately slow and resource-hungry Reversible

Q15. Asymmetric cryptography uses:

One key only One key for encryption and another for decryption No keys Only a hash