albertstill

Plugboard = Hash[*('A'..'Z').to_a.sample(20)]
Plugboard.merge!(Plugboard.invert)
Plugboard.default_proc = proc { |_, key| key }

def build_a_rotor
  Hash[('A'..'Z').zip(('A'..'Z').to_a.shuffle)]
end

ROTOR_1, ROTOR_2, ROTOR_3 = build_a_rotor, build_a_rotor, build_a_rotor