rainbow table attacks
Table of Contents
1. Overview
Rainbow table attacks precompute hashes for common passwords, storing them alongside corresponding plaintexts in a space-efficient data structure called a rainbow table. This allows attackers to quickly reverse lookup hashed passwords obtained from compromised systems.
- Salted passwords render rainbow tables useless: salts(cryptography), unique random values added to each password before hashing, create unique hashes even for identical passwords, negating precomputation.
Example: Ophcrack utilizes rainbow tables to crack Windows LAN Manager (LM) hashes, known for their weakness.
2. Rainbow Tables
2.1. Etymology of rainbow tables
The "rainbow" in "rainbow table" refers to the use of multiple reduction functions during table generation. These functions create chains of alternating hash and reduction operations, producing a colorful spectrum of intermediate values analogous to a rainbow. This technique reduces storage requirements compared to storing all hash-plaintext pairs directly.