gistfile1.rb

  def to_token_string
    key.chars.zip(@secret.chars).join
  end
 
  def self.from_token_string(token_string)
    begin
      key, secret = token_string.chars.each_slice(2).to_a.transpose.map(&:join)
      candidate = self.where(key: key).first
    rescue
      return nil
    end
 
    return nil unless candidate && (candidate.secret == secret)
     
    return candidate
  end