From: bob hope <lists@...>
Date: 2012-08-01T13:41:37+09:00
Subject: Re: working with large binary strings?

Because I have no clue what I am doing :). Thanks. Do you know if there 
is a better way to do this? It seems to be working but I bet there is a 
better way. The goal is, with 4 random strings, to make a 4th random 
string that xors to 0 for each row with the other strings. I don't know 
how to concatenate with a number so that is why I make it a string here.


require "securerandom"
require "openssl"


a = SecureRandom.random_bytes(1_000_000).unpack("B*")[0]
b = SecureRandom.random_bytes(1_000_000).unpack("B*")[0]
c = SecureRandom.random_bytes(1_000_000).unpack("B*")[0]
d = SecureRandom.random_bytes(1_000_000).unpack("B*")[0]

  vsb = ""
  100_000.times do |x|
  puts x
  column = a[x].to_i ^ b[x].to_i ^ c[x].to_i ^ d[x].to_i ^ 0

  case column
  when 0
    vsb << 0.to_s
    else
    vsb << 1.to_s
  end

end

puts vsb.to_i

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