log☇︎
800+ entries in 0.544s
asciilifeform: 'This advisory provides mitigation details for a vulnerability that impacts Tropos Wireless Mesh Routers. An independent research group composed of Nadia Heninger (University of California at San Diego), Zakir Durumeric (University of Michigan), Eric Wustrow (University of Michigan), and J. Alex Halderman (University of Michigan) identified an insufficient entropy vulnerabilitya in SSH key generation in Tropos Networks’s wireless n
asciilifeform: http://btcbase.org/log/2016-09-05#1534601 << freebsd did same, and at the same time removed ~all~ entropy from rng. and distributed this crock of shit for year+. ☝︎
shinohai: Not much entropy in that space.
asciilifeform: it is quite conceivable, given the popping rate, that some large fraction of extant rsa keys have somewhere between 24 and 64 bits of actual entropy.
mircea_popescu: considering we have millions of keys, and considering the sort of shenanigans we've seen currently, including werner koch's gpg subversion most recently ; it would not be inconceivable at this point if a good chunk - thousands, hundreds of thousands of keys can actually be factored once we figure out which exact 20, 30, whatever bits are actual entropy , and how the nextprime is chosen on the basis of that.
mircea_popescu: to be clear here : if the keys are generated out of 16 bits of entropy ; and if there are 65537 keys ; then necessarily there will be at least one weak pair, and in practice more than half ; all of which will be cheaply hacked apart by phuctor's method.
mircea_popescu: but you do have more control over the matter than over entropy source.
asciilifeform: 'It's not at all what I described in my PRNG paper, but I can't tell if that's an accident or by design because, well, there are no code comments. What the GnuPG code does is mix the next 64 bytes and then overwrite the preceding 20 bytes with the mixed output, however this doesn't propagate any entropy along through the buffer.'
asciilifeform: answer given, of course, is 'conserve SCARCE, PRECIOUS' entropy.
mircea_popescu: and no, obd does not need 1mb, or beenfit from it. point was - if you're going to use spare entropy, it would be for this rather than too much waltzing or w/e.
asciilifeform: though funnily enough koch didn't pump ~that~ entropy from the whitened pool
mircea_popescu: r-m needs entropy seed neh ?
asciilifeform: aks isn't a hog because of entropy-eating
mircea_popescu: hence my comment re entropy and its use.
mircea_popescu: AND moreover, most of that legendary mb of entropy should go into the primality test, not into the prime gen
mircea_popescu: suppose i set my keys to be produced with 1mb of entropy.
a111: Logged on 2016-08-18 12:32 mircea_popescu: asciilifeform since we're on this btw, the way i want tmsr-rsa key generation to work is as follows : a contains a number of entropy bytes specified by user in tmsr-rsa.conf read whenever tmsr-rsa.conf specifies (such as urandom); b contains a base-tmsr string specified by user. c = base-tmsr(a).b ; p = nextprime(cut(sha512(c),257)) ; process is repeated for q = nextprime (cut(sha512(c'),258));
mircea_popescu: asciilifeform since we're on this btw, the way i want tmsr-rsa key generation to work is as follows : a contains a number of entropy bytes specified by user in tmsr-rsa.conf read whenever tmsr-rsa.conf specifies (such as urandom); b contains a base-tmsr string specified by user. c = base-tmsr(a).b ; p = nextprime(cut(sha512(c),257)) ; process is repeated for q = nextprime (cut(sha512(c'),258)); ☟︎☟︎☟︎☟︎☟︎
mircea_popescu: such entropy.
mircea_popescu: situation : you go to make key with stock gpg, set it to 4096, ie 512 bytes. it makes you the sign key with 512 entropy bytes, then makes you the encrypt key wirth the remainder 68, and that's it.
mircea_popescu: more's the point here : does that pos actually work so as to get any entropy past the 600 bytes pool ?
a111: Logged on 2016-08-17 21:39 asciilifeform: 'exec summary' for mircea_popescu et al: all gpg keys ever generated have at most 2048 bits of effective entropy.
asciilifeform: 'exec summary' for mircea_popescu et al: all gpg keys ever generated have at most 2048 bits of effective entropy. ☟︎
a111: Logged on 2016-08-06 14:22 mircea_popescu: asciilifeform what's your call, because the matter is quite acute : is it a safer system to demand 8kb entropy/second and hash 12 times ? or to demand say 128bytes/second and hash 768 times ?
mircea_popescu: asciilifeform what's your call, because the matter is quite acute : is it a safer system to demand 8kb entropy/second and hash 12 times ? or to demand say 128bytes/second and hash 768 times ? ☟︎
mircea_popescu: if we actually go with a 12-pass hashing method, this then will require > 8kb of entropy/second from the client, which isn't possibru without dedicated rng fountain.
asciilifeform: the one sticking point may be entropy starvation on certain systems (it is my understanding that a number of eulora players are stuck on winblowz)
BingoBoingo: covertress: Wait, they FIGHT ENTROPY???? BAD ANARCHISTS!!!
mircea_popescu: asciilifeform incidentally, "owned by whitening" is not altogether a bad theory wrt the null-entropy keys. ie, "they replaced rng with null-outputting one, never noticed because whitening". this, of course, doesn't explain why gpg would end up with null-generated keys, but whatevs.
asciilifeform: testing whitened bits which may or may not even have actual physical entropy behind them is ~useless.
asciilifeform: to compactly rephrase, entropy testing is only useful when you ~know the design of the rng~
a111: Logged on 2016-08-03 06:15 mircea_popescu: and speaking of gpg deplorable state asciilifeform can you think of any possible reason the damned thing doesn't come a) bundled with ent and b) with ready implemented tests of local entropy while c) key generation is a subset of entropy testing in all cases ?
mircea_popescu: and speaking of gpg deplorable state asciilifeform can you think of any possible reason the damned thing doesn't come a) bundled with ent and b) with ready implemented tests of local entropy while c) key generation is a subset of entropy testing in all cases ? ☟︎
mircea_popescu: stop mixing shit against entropy flow. you don't give the first of a flying fuck about the number 3. you're wrtiting code, it may not contain magic numbers.
asciilifeform: ^ because human text is low-entropy.
asciilifeform: ... and human lang is quite low entropy.
asciilifeform: http://btcbase.org/log/2016-06-23#1487842 << in that sense. 1) we don't have the huffman table for it in our meat , unlike human text 2) well-designed program has very high entropy. ☝︎
mircea_popescu: the deep stupidity involved should be directly apparent, but in any case - the system as proposed violates the proper flow of entropy, and as such MAY NOT HAVE ANY MERITS.
mircea_popescu: my only thing was with the arrows, because currently they go against the flow of entropy.
asciilifeform: a clearer approach would be to state this in terms of how many bits of entropy, such that is used in generating key, are de facto discarded by the nextprime() op.
Framedragger: yeah seems to have worked for these low entropy pockets around stars, pretty nifty!!
asciilifeform: http://btcbase.org/log/2016-05-20#1469373 << this was hyped worldwide, but for some reason when it turned out that ~3 years of freebsd, ending some time last year, had NO ENTROPY in rng, it was ~nowhere. ☝︎
a111: Logged on 2016-05-19 01:40 mircea_popescu: oh ok, so changed 16^64 to 10^64 and the "generate entropy in the shape of floating point number" thing clearly indicate these fellows are windows programmers with a strong javascript focus.
mircea_popescu: oh ok, so changed 16^64 to 10^64 and the "generate entropy in the shape of floating point number" thing clearly indicate these fellows are windows programmers with a strong javascript focus. ☟︎
mircea_popescu: ah, no, sh is the equiv of entropy. "count of possible states".
mircea_popescu: fromphuctor it's not that hard to find prime numbers. in general, rsa keys should be seeded from a good entropy source.
mircea_popescu: asciilifeform enemy extracting as much as 1 bit of non-entropy.
jurov: you're welcome to make a specifically worn dice that produces only ~2 bits of entropy. i suspect that would be very hard.
asciilifeform: (how much entropy is there actually in a dice throw.)
jurov: is it even physically possible to make biased dice with, 50% less entropy output?
asciilifeform: the boojum is that no mathematical process can create 'additional' entropy.
asciilifeform: you can't distil entropy from where it does not exist, with von n
asciilifeform: yes, it is better than using one's mother's name or 'head' (see http://www.loper-os.org/bad-at-entropy/manmach.html for which sense)
sbp: must, fight, entropy
mircea_popescu: gravity works the way it works ; entropy idem. it doesn't say you can't put things in orbit. it just says it won't be worth it.
mircea_popescu: you're missing the flow of entropy here.
asciilifeform: http://log.bitcoin-assets.com/?date=25-02-2016#1415029 << i am actually very ambivalent about recommending an integer field arithm cipher for use as block cipher on a conventional pc. for one thing, we will have transfer rates measured in kb/sec (if we're lucky.) for another, extreme side channel danger, because we're branching-on-secrets. for a third, entropy starvation. ☝︎
asciilifeform: wait till they get to the part with 'entropy spreading'.
BingoBoingo: They exploded for good reason. Entropy tends to find a way.
mircea_popescu: i suspect it goes deeper than that. something something entropy/and/bandwidth
mircea_popescu: are we confusing entropy and bias here ?
assbot: Logged on 06-02-2016 15:33:16; asciilifeform: i never looked into what his entropy source is. if it's a prng, straight to hell.
assbot: Logged on 06-02-2016 15:33:16; asciilifeform: i never looked into what his entropy source is. if it's a prng, straight to hell.
asciilifeform: i never looked into what his entropy source is. if it's a prng, straight to hell. ☟︎☟︎
mircea_popescu: what colors are your bits, bitch! and how much entropy is there in this dword ?
mircea_popescu: "256 bits has sufficient entropy to render any brute force attack, and even severe weakening (e.g. sq root effort attacks) utterly infeasible." << dude where the fuck do they come from.
assbot: Entropy Forum: Entropy's future, pullmoll am 09.7.2004 22:51 ... ( http://bit.ly/1X8SOhj )
asciilifeform: e.g., 1 and 2 imply that there are sufficient bits per entropy without having to resort to whitenings or distillation
assbot: Zotamedu comments on Bitcoin core will soon replace the industry standard random number generator with a homebrew script. Sorry for your loss (of entropy) ... ( http://bit.ly/1Q8QotN )
mircea_popescu: +/** Add entropy to the pool directly. Use this for seeding or on-demand entropy. */
asciilifeform: we actually don't have an algebra for entropy measures, other than shannon's
mircea_popescu: it is the direct equivalent of entropy-diddling for keysystems.
mod6: re: entropy topic, perhaps ya, we can do something like this when we have a crypto lib 'eh?
mircea_popescu: incidentally, and unrelatedly to the "magic numbers" avenue of trb improvement : one obvious anbd cheap hardening for trb would be to allow the user control of entropy source.
ben_vulpes: should i come up with my own hairbrained scheme to do so or ask how best to get entropy out of this rng directly from you?
mircea_popescu: quite exactly. it'd seem OpenSSL 1.0.1e-fips does not actually utilize entropy to generate keys.
asciilifeform: mircea_popescu: i dont think even my rng gives 4096*typical-miller-rabin-retries bits of entropy in 0.5s
mircea_popescu: punkman apparently discusses what i said about entropy. no idea.
asciilifeform: hey most pc users ~still~ end up with keyboard jitter as entropy source
trinque: deedbot- knows what date/time it is... did someone touch the entropy dial?
asciilifeform: but what, compiler is going to insert an entropy gatherer in the build ?
jurov: with their elaborate entropy management
asciilifeform again sees '7.95260000' and thinks 'not bad...' then remembers it isn't a bits'o'entropy/bt figure
assbot: Limited Entropy Dot Com ... ( http://bit.ly/1HZ6Dfm )
ascii_field: http://www.limited-entropy.com << unrelated, pretty spiffy site
asciilifeform: the design of gpg rng subsystem assumes extreme entropy-starvation. this is plain as daylight from 10 minutes of reading the src.
asciilifeform: gotta understand how, in a prng, the seed is the only genuine bit of entropy;
PeterL: what is it going to do with the entropy it creates?
asciilifeform: * want to be friendly to the scare system entropy resource. */
asciilifeform: * with some entropy drivers, however the rndlinux driver will use
assbot: Logged on 04-12-2015 21:56:53; mircea_popescu: ascii_field "At some point I may do a similar surgical extraction for GPG 1.4.10’s entropy gatherer, but this is a very different project." << i have nfi why you'd be including "software entropy generators".
mircea_popescu: ascii_field "At some point I may do a similar surgical extraction for GPG 1.4.10’s entropy gatherer, but this is a very different project." << i have nfi why you'd be including "software entropy generators". ☟︎
ascii_field feels suitably kicked in arse by mircea_popescu re: entropy
mircea_popescu: so far we're mostly finding novel ways to use up entropy we don't really have.
mircea_popescu: anyway, none of this is even practical without mass cardanos, because iirc c-s consumes even more entropy than rsa.
mircea_popescu: i said "clamp down in one place" not "reduce". how the fuck are you goingto reduce complexity and why aren't you moving on to entropy next!
adlai: http://log.bitcoin-assets.com/?date=16-11-2015#1324960 << 2nd in entropy to abulafia alone ☝︎
BingoBoingo: Seriously the two episodes which triggered this were drunk white kids who said "nigger". Fighting that is like fighting entropy. It's just going to keep happening.
assbot: Logged on 29-10-2015 13:53:11; asciilifeform: http://log.bitcoin-assets.com/?date=29-10-2015#1310695 << basic idea: go and try to actually TEST, e.g., gpg key generator. as in, deterministically. this is nontrivial - gotta saw off the entropy collector and replace with something.
asciilifeform: http://log.bitcoin-assets.com/?date=29-10-2015#1310695 << basic idea: go and try to actually TEST, e.g., gpg key generator. as in, deterministically. this is nontrivial - gotta saw off the entropy collector and replace with something. ☝︎☟︎