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!"