collision.rb

require 'securerandom'
require 'set'

tokens = Set.new

i = ENV['I'].to_i
length = ENV['KEY_LENGTH'].to_i


i.times do |i|
  hex = SecureRandom.hex(length)
  raise "Collision found in iteration ##{i} with key length #{length}!" if tokens.include?(hex)
  tokens << hex
end

print "No collision for #{i} iterations with key length #{length}.\n"

usage: I=10_000_000 KEY_LENGTH=24 ruby collision.rb