asciilifeform: ...if all of your ffa are 'clean' powerof2-sized, you can lose the floor/ceiling thing
asciilifeform: mod6: mircea_popescu's explanation is correct: K is ceil(bitness/2)
asciilifeform: couldn't source a set of lcd glasses that had usefully high switching speed.
asciilifeform: lulzily, long ago, asciilifeform tried to make use of this principle to build a sunglass for seeing lappy lcd in bright sunlight ( sync lcd shutter, a la 'game glasses', to the backlight pwm freq )
asciilifeform: whereas (ideally) 'not so full' of 40kHz light.
asciilifeform: because room is full of, if you will, 'dc' light
asciilifeform: ...drowns in noise, if made any moar sensitive
asciilifeform: whereas if you're a kid and naively build a thing that tries to close a relay when infrared diode sees light and conducts dc -- it will work for maybe a metre, no moar, distance
asciilifeform: receiver samples at the carrier freq (typically 40 or so kHz), and then processed as serial bits.
asciilifeform: concept is usually taught in re radio but applies just as readily in optics -- say, the common infrared remote button
asciilifeform: idea of pll is that you can indeed see a lit match from mile away in daylight if you know 'exactly when to look'☟︎☟︎
asciilifeform: ( if you own, e.g., 'gps' receiver, you already own an example of a device that picks up a signal BELOW motherfucking THERMAL noise!1111 )
asciilifeform: which enemy will -- eventually -- subtract.
asciilifeform: in that you are adding a finite and -- in most cases manageable -- amount of noise to the signal.
asciilifeform: adding random noise -- 'i'll look in the box after T nsec, with T uniform random quantity..' most interestingly does NOT work
asciilifeform: because none of the naive approaches 1) work 2) give any symptom of not working, until you're dead
asciilifeform: the imho interesting part of this tale is that ~time~ is the most, it turns out, difficult side channel to properly cement shut☟︎
asciilifeform: the kindergarten term for the concept is 'side channel'.
asciilifeform: hypothetically i could even do it ( supposing your rsatron is mains-powered ) by observing the imperceptible dimming of the room lights, from 5km away☟︎
asciilifeform: supposing you were using gpg ( or pretty much any other rsatron )
asciilifeform: ben_vulpes: if i ( or whoever ) can time the execution of your mod-exp even to , e.g., 20% accuracy, a couplea times (say, by listening with radio next door) i can derive your p,q.
asciilifeform: as part of the 'pack yer own parachute' philosophy.
asciilifeform: incidentally the time to understand why this recipe works, is now, because users of 'p' will be expected to grasp it and the rest of mechanism
asciilifeform always proofreads equations dropped into teh l0gz, but not necessarily in time!11
asciilifeform: yeah well if mod6 or phf or anybody had tried cooking with this recipe, he'd get headache and wonder wtf asciilifeform was smoking
asciilifeform: sorta how basis of victorian england was the logarithmic table. eggog - sink ship. hence the effort for the steam 'difference engine' etc
asciilifeform: ( it is probably obvious that any conceivable solution - esp in a pointer-avoiding proggy -- will waste much space )
asciilifeform: anyway to round out the thread -- i solved it, in the 'obvious' way, but now gotta simplify the proggy a bit, so that it becomes again readable, and also ideally would like to waste less space
asciilifeform: i'll review karatsuba here, ftr. suppose you have 2 L-bit numbers, X and Y, to multiply. you can multiply X*Y the usual way, is O(N^2). but instead anatoly alexeevich k. shows us that you can cut X into X0,X1, ceil(x/2) and floor(x/2) bits, respectively, and same to Y, -> Y0,Y1, and then you only gotta do THREE multiplications, X0*Y0, X1*Y1, (X0+X1)*(Y0+Y1)
asciilifeform: ( and -- afaik it has never existed, anywhere, anyhow, nowhere to crib, also )
asciilifeform: and wtf was the Official justification.
asciilifeform: gotta wonder, what cost it adds to the bottle, and what effect it has on the surfaces where sprayed, etc
asciilifeform: though i am at a loss to find a clean 'logic' for what gets 'fortified'. for instance i have on my desk now a commonplace can of pseudofreon , and to some surprise discovered 'bitterant to deter snorting' on the ingredients list
asciilifeform: elsewhere in uncleal, 'The FDA screamed "felonious fortification" when makers of cheap fortified wines wanted to add thiamine to prevent alcoholic neuropathy caused by thiamine malabsorption.'☟︎
asciilifeform: 'FDA specifically bans from human infant formula ("felonious fortification") the addition of a tetraunsaturated fatty acid only found in human breast milk. Near as anyone can tell, its only metabolic purpose is to encourage brain development. Human milk for human babies - or you bring up a Democrat.' ftr.☟︎
