[Cryptography] RIP Claude Shannon

[Ray Dillinger]

On 02/23/2016 02:30 PM, Jerry Leichter wrote:
>>> Claude Shannon was lost to us on this day in 2001; he is regarded as the father of information theory, viz: given a noisy comms channel then there are this many bits that you can squeeze through it at most.
>>>
>>> He also did top-secret crypto work in WW2.
>>
>> Supposedly, Shannon worked on voice encryption for phones (a loser, in light of digitization & digital encryption)
> Isn't it great to be able to sit here comfortably in the future, looking back at how silly our predecessors were?  
? Why bother with voice encryption for secure communications during WW
II when all you have to do is wait, oh, 15-20
> years for the concept to be developed, and 40 or so years for it to be really practical?

Whatever the practicality of voice encryption in 1944, I
utterly respect the man who had the out-of-the-box idea of
inducing a phase-locked loop between the frequency of AC
current driving an electric phonograph motor and the
frequency of the transmitter to *exactly* synchronize the
playing of identical phonograph records separated by 6000
miles.

Seriously.  You want a source of randomness?  Try playing the
same phonograph record at exactly the same speed for over
one minute at a time, twice.  Overcoming that to actually *do*
real-time one-time pad encryption on voice communications
over radio, based on additive vectors provided via phonographs,
was a hell of a good original piece of work.

Of course, why the hell the brass wanted *voice*, specifically,
so badly they'd go through an expensive delicate difficult
procedure that took international courier deliveries of keying
material to set up, and involved additional humint security
risks?  And required hiring a guy like Claude Shannon and
however many academic and army technicians to design and
develop new hardware?  It's a dubious priority. Possibly has
something to do with biometric proof of authentication (by
recognizing the individual voice on the other end). People
like Rich Little could spoof it of course, but that's a
fairly rare skill.

				Bear




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