機器
allies
alphabetic
army
century
cipher
code
communication
computer
cryptanalysis
decrypting
decryption
device
electromechanical
encrypting
encryption
enigma
german
germany
historic
historical
history
incandescent
intelligence
key
letter
mechanical
military
number
old
past
polyalphabetic
radio
record
rotor
rotor machine
russian
scrambler
second world war
secret
secret messages
sign
signal
symbol
technology
transmissions
war
warfare
world