SY0-501 · Question #31
Which of the following characteristics differentiate a rainbow table attack from a brute force attack? (Select TWO).
The correct answer is A. Rainbow table attacks greatly reduce compute cycles at attack time. B. Rainbow tables must include precompiled hashes. Rainbow table attacks use precomputed hash lookups to crack passwords faster than brute force, which computes hashes on-the-fly during the attack. The two key differentiators are the use of precompiled hashes and reduced computation at attack time.
Question
Which of the following characteristics differentiate a rainbow table attack from a brute force attack? (Select TWO).
Options
- ARainbow table attacks greatly reduce compute cycles at attack time.
- BRainbow tables must include precompiled hashes.
- CRainbow table attacks do not require access to hashed passwords.
- DRainbow table attacks must be performed on the network.
- ERainbow table attacks bypass maximum failed login restrictions.
How the community answered
(27 responses)- A70% (19)
- C4% (1)
- D7% (2)
- E19% (5)
Why each option
Rainbow table attacks use precomputed hash lookups to crack passwords faster than brute force, which computes hashes on-the-fly during the attack. The two key differentiators are the use of precompiled hashes and reduced computation at attack time.
Unlike brute force attacks that must compute a hash for every candidate password in real time, rainbow table attacks perform the expensive hash computations offline in advance, so the attack phase itself only requires fast table lookups, dramatically reducing the compute cycles needed at attack time.
A rainbow table is by definition a precompiled data structure containing pre-calculated hash chains or hash-to-plaintext mappings; without these precompiled hashes the lookup mechanism does not exist, making this a fundamental and defining characteristic that separates it from brute force.
Rainbow table attacks still require access to the target's hashed passwords - the precomputed hashes in the table are compared against the stolen hashes to find matches, so this is not a differentiating characteristic.
Rainbow table attacks are performed offline against captured hash dumps, not on the network; if anything, being off-network is more characteristic of rainbow table attacks than brute force, making this statement false.
Rainbow table attacks operate offline against a stolen hash database and never interact with the live authentication system, so account lockout policies are irrelevant to both rainbow table and offline brute force attacks - this is not a unique differentiator.
Concept tested: Rainbow table vs brute force password attack characteristics
Source: https://learn.microsoft.com/en-us/windows-server/security/kerberos/passwords-technical-overview
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