Editing Cryptanalysis of the Enigma (section)

===Italian naval Enigma===
{{see also|Cryptanalysis of Italian naval codes}}
In 1940 Dilly Knox wanted to establish whether the Italian Navy were still using the same system that he had cracked during the Spanish Civil War; he instructed his assistants to use rodding to see whether the crib ''PERX'' (''per'' being Italian for "for" and ''X'' being used to indicate a space between words) worked for the first part of the message. After three months there was no success, but [[Mavis Batey|Mavis Lever]], a 19-year-old student, found that rodding produced ''PERS'' for the first four letters of one message. She then (against orders) tried beyond this and obtained ''PERSONALE'' (Italian for "personal"). This confirmed that the Italians were indeed using the same machines and procedures.<ref name=CarterRodding/>

The subsequent breaking of Italian naval Enigma ciphers led to substantial Allied successes. The cipher-breaking was disguised by sending a [[aerial reconnaissance|reconnaissance aircraft]] to the known location of a warship before attacking it, so that the Italians assumed that this was how they had been discovered. The Royal Navy's victory at the [[Battle of Cape Matapan]] in March 1941 was considerably helped by Ultra intelligence obtained from Italian naval Enigma signals.<ref name=batey>{{Citation |last=Batey |first=Mavis | author-link = Mavis Batey |title=Breaking Italian Naval Enigma |year=2011 |page=81}} in {{Harvnb|Erskine|Smith|2011|pp=79–92}}</ref>