the.com/rainbow tables
a phonebook for passwords, precomputed so cracking becomes a lookup, not a fight.
means a rainbow table is a giant precomputed set of hash-to-password mappings that lets an attacker reverse a stolen hash almost instantly instead of guessing forever.
from built on a 1980 time-memory tradeoff idea by martin hellman, then made practical in 2003 when philippe oechslin added chained reduction functions to shrink storage while keeping speed.
tradeoff tricktrades cpu time for storage using hash chains
killed bysalting, which makes precomputation useless
speed gainturns years of brute force into seconds
chain compressionstores only chain endpoints, not every hash
for instance
ophcrack — free tool cracking windows lm hashes since 2006
rainbowcrack project — oechslin's original implementation, released 2003
free rainbow tables — crowdsourced table-generation project active mid-2000s to 2010s