Charles Babbage (London, 1791–1871) breaks the Bellaso/Vigenère polyalphabetic cipher c.1846 through statistical analysis of the key period, but does not publish the method. Friedrich Wilhelm Kasiski (Schlochau, 1805 – Neustrelitz, 1881), a Prussian officer with no known connection to Babbage, independently publishes the same method in Die Geheimschriften und die Dechiffrir-Kunst (Berlin, 1863). The method — now called the Kasiski test — consists of detecting repetitions in the ciphertext to deduce the key length and then apply frequency analysis to each monoalphabetic subgroup. The cipher that had resisted three centuries of diplomatic and military use is broken. Babbage is the silenced case: his notebook with the analysis dates to c.1846; Kasiski publishes in 1863 without knowing of Babbage's work, which was not discovered until the 20th century.