[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: NSA, Random Number Generation, Soviet Codes, Prohibition of

In the book I mentioned there is a quotation of D. Kahn, The
Codebreakers, from 1967:

"Interestingly, some pads seem to be produced by typists and not by
machines. They show strike-overs and erasures - neither likely to be
made by machines. More significant are analsyses of the digits.
One such pad, for example, has seven times as many groups in which
digits in the 1-to-5 group alternate with digits in the 6-to-0
group, like 18293, as a purely random arrangement would have.
This suggests that the typist is striking alternately with her
left hand (which would type the 1-to-5 group on a Continental
machine) and her right hand (which would type the 6-to-0 group).
Again, instead of just half the groups beginning with a low number,
which would be expected in a random selection, three quarters of
them do, possibly because the typist is spacing with her right
hand, then starting a new group with her left. Fewer doubles and
triples appear than chance expects. Possible the girls, ordered
to type at random, sensed that some doublets and triplets would
occur in a random text but, misled by their conspiciousness,
minimized them. Despite these anomalies, however, the digits
still show far too little pattern to make cryptanalysis possible."

Ulf Möller * um@ulf.mali.sub.org * 3umoelle@informatik.uni-hamburg.de
PGP key fingerprint: B6 4F 97 28 8F C0 54 C3  A6 10 02 2F B9 31 78 14 
"When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl!"