easy to know about rotor machine

1. M.SUJITHA,
II-M.SC(CS&IT),
Nadar Saraswathi College Of Arts And Science,
Theni

2.  A rotor machine is an electro-mechanical stream
cipher device used for encrypting and decrypting secret
messages.
 Rotor machines were the cryptographic state-of-the-art for a
prominent period of history; they were in widespread use in
the 1920s–1970s.
 The most famous example is the German Enigma machine,
whose messages were deciphered by the Allies during World
War II, producing intelligence code-named Ultra.

4.  Asubstitution cipher is a method of encrypting by which units of plaintext
are replaced with ciphertext,
 According to a fixed system; the "units" may be single letters pairs of
letters, triplets of letters.