65100+ entries in 0.037s
BingoBoingo: In other updates: Cansorship resistance piece approaching 1500 words and has yet
to advance beyond 2014 Republican state of
the art.
mircea_popescu: to be clear : it's exactly
the same scheme ; showing you how P ~must~ be obtainable from known K and E.
mircea_popescu: so if K[q] = 0,
then
that line's skipped ; otherwise it's applied.
mircea_popescu: no no, x is xor * is multiplication (in
the sense
that if
the key is 0 at
that offset,
the rb dun get applied)
mircea_popescu: for a 5 bit key you only have
to
try 2^3 permutations or so, it's
true. but anyways.
mircea_popescu: To obtain P back from E without K : P[1] = P[1] x K[1] * P[1] x K[2] * P[2] x K[3] * P[3] x K[4] * P[4] x K[5] * P[5] ; P[2] = P[2] x K[1] * P[2] x K[2] * P[3] x K[3] * P[4] x K[4] * P[5] x K[5] * P[6] ; and so following all
the way down.
mircea_popescu: E
therefore is : E1 = 0 x 0 x 1 = 0 ; E2 = 0 x 0 x 1 = 0 ; E3 = 1 x 1 x 0 = 0 ; E4 = 1 x 1 x 0 = 1 ; E5 = 1 x 1 x 1 = 0
thus E = 00010.
a111: Logged on 2018-10-29 18:29 asciilifeform: it's about xor, in
the specific style used in winblowz shitware
to hide strings from av.
mircea_popescu: as long as P doesn't have more bits
than K,
this is a determinate system.
mircea_popescu: so
this is, in fact, a system of (here) 512 xor-equations, with ak nown result (e[x]) and a known parameter matrix (K)
mircea_popescu: asciilifeform check
this out : as per
the "chipher", let
there be a plaintext P of n bits ; and a key K of k bits. given a ciphertext E of n bits, it is a fact
that any one bit of P is
the result of xoring of up
to k bits of P. if you know K you know ~which ones~, and as you have E you know ~what
they must xor
to~.
this results in a message-wide system of k equations which is determinate.
a111: Logged on 2018-10-29 19:22 diana_coman: asciilifeform,
that helps,
thank you! I had
to
take break and I'm slow on
this sort of
things so it'll
take a while until I get
to say anything
mircea_popescu: asciilifeform
this is so much better
than having
to correct
the
title.
mircea_popescu: "our block cipher has
to have backdoor because we built a paper shredder and well..."
diana_coman: asciilifeform,
that helps,
thank you! I had
to
take break and I'm slow on
this sort of
things so it'll
take a while until I get
to say anything
☟︎ mircea_popescu: and no, "we have pre-padded ring buffers with
THIS particular message
that's worth hardwiring because it's ever so magical" ain't a reasoning.
mircea_popescu: asciilifeform like it or not,
this is
the ur-blockchipher. ALL OTHERS, not only casually but NECESSARILY, are mini-clipped versions of
this. "competition or no competition", if it got shitboxes it's
this and naught else.
mircea_popescu: ow shit, i mystypoed in
the
title, wtf is a "chipher".
mircea_popescu: i'd have said more, but
the editor showed wordcount 777, and i deem
this a very good omen re cipher quality.
diana_coman: I can cite
though from
the 2000 paper (or apparently 2000...): "Since
then we have sought
to strengthen
the algorithm and improve its performance. As a result, we have selected new, stornger, S-boxes and changed
the key schedule slightly."
mircea_popescu: bright kid walks in with a convincing story as
to how he's gonna walk in with item != bright kid walks into here one day with
that item.
a111: Logged on 2018-10-26 17:05 mircea_popescu: yeah but suppose some bright kid walks into here one day with
that item we all suspect is under a rock somewhere
BingoBoingo: asciilifeform: If your math stands
the week, you may be
the best qualified
to do
the qntra on it
a111: Logged on 2018-10-26 17:04 mircea_popescu: in short, because
this winding discussion risks overwhelming buffers,
the salient points are a)
that i'm not ready
to go
to war over serpent, it's a meh-maybe item ; b)
that building our spearheads around items we're not willing
to die for may be how
the converse of
http://btcbase.org/log-search?q=bitcoin+corrupts altogether.
a111: Logged on 2018-10-26 16:48 mircea_popescu: i am experimenting with serpent, and yes it's borne of
that ancient discussion of ours, but i'm nowhere near-ready
to bake it into "this is
tmsr secure disk"
mircea_popescu: asciilifeform likely explanation being "whisperer", ie,
technical quimby sinking it behind
the doors because "it's fucking stupid".
mircea_popescu: asciilifeform consider also
that if a, b, c, d, e, f are rng words,
then (P xor a) xor b) etc does not in fact substract anything.
mircea_popescu: the reason being
that it wasn't gonna move
till i baked it in some pie.
a111: Logged on 2018-10-29 16:06 asciilifeform: nao, is it a controversial statement
that xors with an item
that's already been rolled in, can only ~subtract~ entropy, never add ?