▁the ▁Polish ▁techniques , ▁the ▁British ▁began ▁reading ▁En igma ▁ci ph ers ▁in ▁collaboration ▁with ▁Polish ▁Ci pher ▁Bureau ▁crypt olog ists ▁who ▁had ▁escaped ▁Poland , ▁over run ▁by ▁the ▁Germ ans , ▁to ▁reach ▁Paris . ▁The ▁Pol es ▁ ▁continued ▁breaking ▁German ▁Army ▁En igma — al ong ▁with ▁Luft wa ffe ▁En igma ▁traffic — until ▁work ▁at ▁Station ▁PC ▁Bruno ▁in ▁France ▁was ▁shut ▁down ▁by ▁the ▁German ▁invasion ▁of ▁May – J une ▁ 1 9 4 0 . ▁ ▁The ▁British ▁continued ▁breaking ▁En igma ▁and , ▁assist ed ▁eventually ▁by ▁the ▁United ▁States , ▁extended ▁the ▁work ▁to ▁German ▁Naval ▁En igma ▁traffic ▁( which ▁the ▁Pol es ▁had ▁been ▁reading ▁before ▁the ▁war ), ▁most ▁especially ▁to ▁and ▁from ▁U - bo ats ▁during ▁the ▁Battle ▁of ▁the ▁Atlantic . ▁ ▁Vari ous ▁machines ▁ ▁During ▁World ▁War ▁II ▁( W W II ), ▁both ▁the ▁Germ ans ▁and ▁Al lies ▁developed ▁additional ▁rot or ▁machines . ▁The ▁Germ ans ▁used ▁the ▁Lor enz ▁S Z ▁ 4 0 / 4 2 ▁and ▁S iem ens ▁and ▁H als ke ▁T 5 2 ▁machines ▁to ▁en ci pher ▁tele pr inter ▁traffic ▁which ▁used ▁the ▁Baud ot ▁code ; ▁this ▁traffic ▁was ▁known ▁as ▁Fish ▁to ▁the ▁Al lies . ▁The ▁Al lies ▁developed ▁the ▁Type x ▁( B rit ish ) ▁and ▁the ▁S IG AB A ▁( American ). ▁During ▁the ▁War ▁the ▁Swiss ▁began ▁development ▁on ▁an ▁En igma ▁improvement