338000+ entries in 0.239s
punkman: mp must guess how many of
the 100 ciphertexts are made from
the string ""mircea_popescu: long, deeply biased plaintexts are dangerous for otp.""
punkman: the
third variant is also ok I
think
mircea_popescu: you can make as many otps as you want, it's still coming out
the same way o.O
punkman: other variant: ascii makes 100 otps, makes 100 plaintexts, X of which are
the string "mircea_popescu: long, deeply biased plaintexts are dangerous for otp.",
then passes 100 ciphertexts
to mp. mp must guess X withing some range.
mircea_popescu: ok i guess ima have
to figure out some way
to hm. hey asciilifeform , how about
this deal : i pay you 10 btc of my eventual winnings, should
they exist, but you make
the messages and show
the result. i dun have a compiler ready and nfi how you generate
the described messages in bash
mircea_popescu: han byte n-1.
The larger of
the
two indicates
the message encrypted ;
the difference between
these counts indicate your confidence (or
the rng's bias).
mircea_popescu: asciilifeform : Let message A consist of individual bytes counting down from FFFFFFFF ; let message B consist of individual bytes counting up from 00000000. Let
the enemy xor one of
these
two against a random, unbiased OTP of
the same length and supply
the enciphered result.
Take
that result, and count
the instances where byte n is larger
than byte n+1.
Take
that result, and count
the instances where byte n is larger
t punkman: well not in kindergarten, but I did play
this game on paper once
punkman: if you want
to do 1, must have 1000 plaintexts instead
mircea_popescu: that i guess your message. which i suppose necessarily carries
the caveat
that "must not be by chance",
mircea_popescu: asciilifeform notice
that
this isn't "wins/loses". you're just giving 10 btc away, on
the if.
thestringpuller: and
this is what #b-a is
the most amazing channel on freenode
mircea_popescu: mk, ima bbl see if i can hack
together something
that satisfies
the audience
theoretically.
mircea_popescu: it really needn't be done over more
than one
try lol. srsly ? 1k ?
punkman: mp makes 2 plaintexts, ascii generates 1000 otps, for each otp: picks one of
the 2 plaintexts and xors with otp. mp must guess guess correctly 501?, 600? more?
mircea_popescu: you don't see
the crc discussion sufficient for our purposes ?
mircea_popescu: and if
the plaintext is long enough,
this is equivalent
to a requirement of minimal bias in
the otp pad.
mircea_popescu: but in general, if you do away with
the requirement
to recover ALL of
the plaintext,
mircea_popescu: how biased
the otp needs
to be is part of
the crc spec, for instance "every 8th bit may be a 1" etc.
mircea_popescu: let me put it
this way : stuff like CRC, or ECC etc, exists fundamentally out of "we guarantee you can recover
the plaintext after it has been otp'd with a pad which is AT LEAST
this biased"
mircea_popescu: the examples given are not structured and readily reduce
to "1" and "0", so no, it wouldn't work here.
mircea_popescu: if you're making 1 mb of 01111110 and 1mb of 10000001 and
then otp
them against a random pad
punkman: so you'd be able
to pick
the right message more
than 50% of
the
time?
mircea_popescu: asciilifeform funny how money clears
the mind, even if it's
too little
to mention.
mircea_popescu: punkman why, he didn't feel obliged
to add any btc
to
the other one, just bitch about
the insufficiency of
the sum.
punkman: should add some btc
to challenge :)
mircea_popescu: you pick one of
two lengthy, structured plaintexts i provide, you encrypt
them with a biasless, purely random rng, and i decide which of
the
two you picked.
mircea_popescu: are you paying me 10 btc if we do
this experiment and i do guess it, "with
telepathy, at home" ?
punkman: you would find infinite
texts
that make sense
mircea_popescu: there is another way
to die using otp, and
that way is
to use a lengthy biased message
the enemy knows most of.
mircea_popescu: this alone should show
they're deeply inadequate, but who knows fundamentals anymore.
mircea_popescu: asciilifeform
technically speaking,
the s-box cipher crapolade is an ellaborate exercise in reusingselect parts of otp