Re:The two-time pad: midwife of information theory?
by georgecmu on Wednesday July 18, 2018 @02:44PM
(#17561013)
This comment doesn't make much sense. This one/two-time pad system was in use for all diplomatic traffic; not just by the intelligence agencies.
See pages 47-49 here: https://nsarchive2.gwu.edu/NSAEBB/NSAEBB278/01.PDF
Re:The two-time pad: midwife of information theory?
by gruez on Wednesday July 18, 2018 @02:26PM
(#17560867)
> [Against clear orders] The printers decided to print four copies of each pad then send two each to the KGB and GRU. Neither the KGB nor the GRU reused the pads they received, except perhaps because of occasional operator error.
why? how much more expensive could it be to generate new random numbers? do they not have cheap/fast RNGs?
Re:The two-time pad: midwife of information theory?
by pdpi on Wednesday July 18, 2018 @03:15PM
(#17561274)
In the 40s? Probably not, no. This was a relevant and useful book when it was published — https://en.m.wikipedia.org/wiki/A_Million_Random_Digits_with...
Generating randomness is hard, and a recent concern.
Re:The two-time pad: midwife of information theory?
by kragen on Thursday July 19, 2018 @08:06PM
(#17571440)
One of the useful things about that book was that using it provided evidence that you didn't choose your "random" numbers through some tricky process designed to produce a certain nonrandom result.
Re:The two-time pad: midwife of information theory?
by ballenf on Wednesday July 18, 2018 @02:34PM
(#17560937)
He doesn't answer the 'why' but there's an implication that the printing shop had orders to produce X number of one time pads and it was half the work to setup the apparatus this way. Basically it was a shortcut that presumably felt entirely reasonable to folks running the printing press. And maybe even technically compliant with their instructions depending on the wording thereof.
> The Russians had two intelligence organisations ... the KGB and the GRU. Both organisations knew that they should not reuse one-time pads.
> [Against clear orders] The printers decided to print four copies of each pad then send two each to the KGB and GRU. Neither the KGB nor the GRU reused the pads they received, except perhaps because of occasional operator error.
> ... Subtracting one message from the other cancelled out the unknown key to produce a synthetic message that was the difference between the two original messages. These could then be picked apart using a combination of statistics and predictable words.
> - Mark Lomas