<prompt> Pedzisa mutsara unotevera: Muna 1939, iye akaita nzendo dzinokosha kupinda muJN-25, kodhi yokushandisa yezvikepe zveJapan inoshandiswa nokuda kwemashoko anokosha zvikurusa. Akabudirira kugadzirisa cipher chikamu che 5-num system iyo yakashandisa mapoka enhamba sevanotsiva mazwi nenhamba iyo yakawedzera kunyorwa nedhijitari. Pashure paikoko, Navy yaigona kurava mashoko omutoo wakajairika, akadai semishumo yemamiriro okunze, asi rutivi rukuru rwemashoko rwakanga rwuchiri kufanira kuwanwa. Iri basa rakazogadziridzwa uye rakashandiswa pashure pokurwiswa kwePearl Harbor kwehondo yose yePacific uye rakapa nyevero yapamberi yezvipingamupinyi zvehondo.  <response>: VaJapan vanorwisa Midway Atoll. Haana kukwanisa kuita basa iri nokuti, muna October 1940, akaendeswa kuchikwata chaishanda kuti chivhure kodhi yeEnigma yemasoja eGermany. 