Magic (cryptography) - History

History

When PURPLE was broken by the U.S. Army's Signals Intelligence Service (SIS), several problems arose for the Americans: who would get the decrypts, which decrypts, how often, under what circumstances, and crucially (given interservice rivalries) who would do the delivering. Both the U.S. Navy and Army were insistent they alone handle all decrypted traffic delivery, especially to highly placed policy makers in the U.S. Eventually, after much toing and froing, a compromise was reached: the Army would be responsible for the decrypts on one day, and the Navy the next.

The distribution list eventually included some — but not all — military intelligence leaders in Washington and elsewhere, some — but, again, not all — civilian policy leaders in Washington. The eventual routine for distribution included the following steps:

  • the duty officer (Army or Navy, depending on the day) would decide which decrypts were significant or interesting enough to distribute
  • they would be collected, locked into a briefcase, and turned over to a relatively junior officer (not always cleared to read the decrypts) who would 'make the rounds' to the appropriate offices.
  • no copies of any decrypts were left with anyone on the list. The recipient would be allowed to read the translated decrypt, in the presence of the distributing officer, and was required to return it immediately upon finishing. Before the beginning of the second week in December 1941, that was the last time anyone on the list saw that particular decrypt.

Read more about this topic:  Magic (cryptography)

Famous quotes containing the word history:

    The steps toward the emancipation of women are first intellectual, then industrial, lastly legal and political. Great strides in the first two of these stages already have been made of millions of women who do not yet perceive that it is surely carrying them towards the last.
    Ellen Battelle Dietrick, U.S. suffragist. As quoted in History of Woman Suffrage, vol. 4, ch. 13, by Susan B. Anthony and Ida Husted Harper (1902)

    They are a sort of post-house,where the Fates
    Change horses, making history change its tune,
    Then spur away o’er empires and o’er states,
    Leaving at last not much besides chronology,
    Excepting the post-obits of theology.
    George Gordon Noel Byron (1788–1824)

    History does nothing; it does not possess immense riches, it does not fight battles. It is men, real, living, who do all this.... It is not “history” which uses men as a means of achieving—as if it were an individual person—its own ends. History is nothing but the activity of men in pursuit of their ends.
    Karl Marx (1818–1883)