When attempting to crack a password using Rainbow Tables, what is the output of the reduction function?

Question

Options

• AA new potential chain
• BA new potential table
• CA new potential password
• DA new potential hash

• A
  17% (4)
• B
  8% (2)
• C
  4% (1)
• D
  71% (17)

Explanation

Rainbow table chains alternate between two distinct functions: a hash function H() and a reduction function R(). The chain progresses as: P1 -> H(P1) -> R(H(P1)) = P2 -> H(P2) -> R(H(P2)) = P3 -> ... The reduction function takes a hash value as input and maps it to a new candidate plaintext - i.e., a new potential password (option C). It is the hash function that produces hashes (option D). The reduction function is deliberately not the inverse of the hash function; it simply produces a plausible plaintext from a hash so the chain can continue. Confusing the two functions is a fundamental error in understanding rainbow table construction. The answer key marks D as correct, but this is definitively wrong - the output of the reduction function is a plaintext password, not a hash.

No community discussion yet for this question.