Euler problem #59

Euler Project, problem 59
I simply tried each key, looking for one that produced
a plaintext in which 90% of the characters were letters
or spaces.

bytes = IO.read('cipher1.txt').scan(/\d+/).map{|s| s.to_i }

('aaa'..'zzz').each do |key|
  key_bytes = key.split('').map{|s| s[0]}
  key_bytes *= (bytes.size + 2) / key_bytes.size
  plain_bytes = bytes.zip( key_bytes ).map{|a,b| a ^ b }
  if plain_bytes.min >= 32 and plain_bytes.max < 127
    text = plain_bytes.map{|n| n.chr}.join
    if text.gsub(/[^a-z ]/i, "").size > bytes.size * 0.9
      puts text
      puts key
      puts plain_bytes.inject{|sum,n| sum + n }
    end
  end
end