Steven Bellovin Talk at NSA History Conference today:
   Vernam, Mauborgne, Friedman: The One-Time Pad and the Index of
   Coincidence
   [1]https://www.cs.columbia.edu/~smb/talks/VernamMauborgneFriedman.pdf

References

   1. https://www.cs.columbia.edu/~smb/talks/VernamMauborgneFriedman.pdf