Crypto Attack Quiz: Birthday, Collision Or Downgrade?

1. What does 'second preimage resistance' prevent in a cryptographic hash function?

Creating two different messages with the same hash

Finding the original message from its hash

Reversing the hash to plaintext

Decrypting data without the key

2. What is the primary defense against birthday attacks on cryptographic systems?

Using longer hash outputs

Implementing rate limiting

Applying digital signatures

Requiring multi-factor authentication

3. A collision in a digital signature hash allows an attacker to forge a signature for which document?

Any document not yet signed

A different document with the same hash

The original document only

Documents from the same issuer

4. Which mechanism prevents downgrade attacks by ensuring protocol agreement cannot be modified?

Cipher suite negotiation logging

Cryptographic binding of protocol version

Increased authentication timeouts

Mandatory certificate revocation

5. The Heartbleed vulnerability allowed attackers to read server memory. What protocol did it affect?

SSH

OpenSSL

IPsec

DNSSEC

6. In a downgrade attack on HTTPS, what does the attacker typically force the connection to use?

HTTP instead of HTTPS

Older TLS versions with weaker ciphers

Self-signed certificates

Expired encryption keys

7. Which cryptographic algorithm is most resistant to collision attacks due to its design?

MD5

SHA-1

SHA-256

DES

8. A successful birthday attack against a hash function typically requires how many computations?

Square root of the output space

The full output space

Logarithm of the output space

One-tenth of the output space

9. The DROWN attack exploits SSLv2 to compromise which modern protocol?

TLS 1.2 and higher

HTTPS connections

VPN protocols

IPsec tunnels

10. Which attack involves an attacker negotiating the weakest possible encryption between client and server?

Man-in-the-middle attack

Downgrade attack

Replay attack

Dictionary attack

11. What is the primary goal of a birthday attack in cryptography?

Find two different inputs that produce the same hash output

Compromise the birthday of a certificate holder

Exploit leap year dates in digital signatures

Reverse-engineer a one-way hash function

12. In a birthday attack scenario, an attacker generates many variations of a document to find two with identical hashes. What is this attack called?

Meet-in-the-middle attack

Hash collision attack

Brute-force attack

Rainbow table attack

13. A collision attack on MD5 demonstrates which security weakness?

Insufficient key length

Broken collision resistance

Weak random number generation

Poor key management

14. Which mitigation strategy best prevents downgrade attacks in TLS handshakes?

Disabling older protocol versions

Increasing cipher key length

Using longer session timeouts

Implementing certificate pinning

15. The birthday paradox suggests that collisions in a 256-bit hash become probable after approximately how many random inputs?

2^256 attempts

2^128 attempts

2^64 attempts

2^32 attempts

16. In the context of hash functions, what does 'preimage resistance' protect against?

Finding two inputs with the same hash

Finding any input that produces a specific hash

Modifying data without changing its hash

Brute-forcing encryption keys

17. Which protocol is vulnerable to POODLE (Padding Oracle On Downgraded Legacy Encryption)?

TLS 1.3

SSL 3.0

DTLS 1.2

QUIC

18. A downgrade attack typically forces a system to use which of the following?

Stronger encryption algorithms

Weaker or deprecated protocols

Longer cryptographic keys

Multi-factor authentication

19. Which cryptographic property does a collision attack directly exploit?

Confidentiality of encrypted data

Integrity of hash-based signatures

Authentication of digital certificates

Key exchange protocol establishment

20. In a birthday attack against a hash function with 128-bit output, approximately how many hashes must be computed to find a collision?

2^128

2^64

2^32

2^16

Crypto Attack Quiz: Birthday, Collision or Downgrade?