in ECDSA, when you use m of n multi-sig you have to provide a signature for each m and a public key for each n. each signature takes up about 72 bytes and each public key takes up 34 bytes inside a transaction. so for a 15 of 15 you have to produce a signature that is nearly 1600 bytes.

in ECSDSA (Schnorr) when you use m of n multi-sig you only provide one signature and one public key (the aggregated pubkey) so a 15 of 15 multi-sig is the same size as a single sig (like P2PKH) signature ~106 bytes.
that is how Schnorr algorithm works, i haven't read the bips entirely yet but i believe they also changed the signature encoding. if that's true then signature size would be 64 bytes and it would take up 65 bytes in a signature (1 byte size + 32 byte R + 32 byte S)

it is not possible to expect the immediate next move that bitcoin is going to make at times like this where price has a big drop out of nowhere which scares investors into adopting a wait-it-out strategy instead of buying. so all you can do is either take the bigger risks and get involved in the market or do what most others do and wait for the rise then jump back in with a FOMO!
my guess is that we will see this price level for a longer time without going either up or down. then either an attempt to push it down will occur and fail because of the strong buy support at $8k or we simply see a rise to break above $9k at a slow pace then as it goes above that the price shoots up to above $10k-11k

because as a project in find ethereum to be terrible:
it is centralized, it has a lot of issues such as exploits in their smart contracts, the scaling problems, the impossibility of running a full node because of its ridiculously huge space requirement (3.22 TB as of this writing, compared to bitcoin that needs ~300 GB), the lack of immutability, and generally being a bad project. on top of that it has unlimited supply which automatically makes it a bad long term investment.

no, that is not double spending. it is just an unconfirmed transaction which has always been unsafe to accept (considered as payment being made for instance). also remember that when a transaction is made and broadcast to the network, technically it can remain out there forever. for instance the receiver can store it locally and keep broadcasting it until it either is confirmed or becomes invalid. so technically it could never "gets returned to person 1".

this transaction could be considered a "double spend" only if person 1 spends the same input of that transaction in another transaction sending the coins to another different destination. an act which would make one of the transactions invalid (depending on which tx nodes have in their mempool or if one becomes confirmed)

what kind of catastrophic event are we talking about here that could lead to annihilation of all nodes on earth worldwide that we need a space node?!! and what would we need that if the human race is extinct, or is it just extinction of computers on earth

what's up with people and the word "continue"? this is not the first time i see someone make this mistake. price dropped from $10k down to $8k on 24th and that whole thing took only one day. price has been down ever since with less than 5% fluctuations. you can't call that "continues to drop".


it is just you and what you are saying here is contradictory.
if bitcoin were to drop then altcoins would drop harder so there is no point in buying them as it is pretty much a guaranteed dump. additionally if traders weer accumulating altcoins their prices should have gone up as their markets are so much smaller and their accumulation phases are short leading to fast pumps. but none of it is happening.

people who have stopped coming to this forum had their reasons such as being busy in real life with jobs, family obligations,... so even if you brought them back, they won't be as active as before since those reasons that led to their departure would still be there.

besides i believe it is best if we get more new people in mainly by improving the contents. for instance i hope to see a more active technical discussion boards specially in general cryptocurrency and blockchain topics not just bitcoin focused and we still don't have any board for that.

you said you wanted to buy bitcoin and ether (an altcoin which i would never buy) with fiat not with bitcoin or stable altcoins. Binance is an altcoin exchange that doesn't have any fiat market as far as i know. all they have is altcoins versus bitcoin and altcoins versus some stable coins like tether.
https://coinmarketcap.com/exchanges/binance/ pay attention to that T at the end of USDT.

edit: i missed @Lucius post above about their .je platform. it is weird how they keep creating so many new platforms!

of course when your entire information comes from reading what random people (advertising an altcoin which they are bag holding and want to see pumped) tell you, you'll end up thinking they are different and more advanced! but when you look at them under the hood you can clearly see majority of altcoins are exact copies of bitcoin with so small number of differences and in all cases those differences could even be considered weaknesses because they have opened up new attack surfaces.

hashes could never be "reversed" and it is not exactly about efficiency it is about virtually unlimited solutions. think of it like this, if i say i have a big number that is the sum of 10 other numbers you will never be able to guess what those 10 values were because there simply is too many possibilities.

the difference between hashing and ECC is that ECC is pure math so there could some day be a solution to solve that reverse mathematical problem (ECDLP) in a faster way but hashing is a complete chaotic algorithm where we take an input "mutate" it, toss the bits around and come up with a neat result. so the only way to attack hashing algorithms has always been to find collision meaning if i said "a85845e696ee7aac1b012d611edcbd6fbf1884c5" is my SHA1 hash you will never be able to find out what message i hashed but you could find another message some day (you still can't do it today even for SHA1) that could give the same result.

coinmarketcap.com is a terrible site mainly because of the way they are ranking coins (based on market cap) and have other misleading rankings such as "dominance" but all the data they provide is accurate. whether some people don't understand it is their own fault.

did you even read any of the replies?!

true but the public networks that you are talking about here are free internet services that these shops are kind enough to let people use without charge so i don't think there is any room for complaining about how they let people use it. not to mention that nodes could use up quite a lot of traffic depending on their settings.

the real question is whether SEC cares about any of them! i don't think so. and so far they have not changed their stance against all these bitcoin ETFs and have been consistent in their denial of each of the proposals without any exceptions. this time i don't see anything different that could suggest a different decision from SEC!

having such features should actually discourage you from using a smart phone as your "cold" storage because it is defeating the main and only purpose of such wallets which is being "cold" or in other words being cut off from the rest of the world. if your phone is still capable of broadcasting anything (such as your location) it can broadcast a ton of other things too. being closed you won't have any way of knowing what it sends either.

sure, but you didn't say you were talking about the greatest projects in the world. your question is too general which is why my answer was general. i don't even know what type of project and what type of weakness you have in mind!

investing in ICOs has always been a gamble, back in 2017 when they were too hyped up the odds of "winning the bet" was high but nowadays that the hype is dead for good, the odds are against you.
for that reason nobody can tell you how long it could take to get a profit if any at all. but as a rule all the ICOs have so far gotten an initial big pump then dumped and died slowly. so if there were any profit it would be in the early weeks of its listing on and exchange the longer it gets the lower the risk of pumping any more.

why should the project have any weak points in first place?
besides, it depends on what the "project" is. is it a business like an exchange,... (since you mentioned paying a lot of money for it) or is it just an open source cryptocurrency (in which case paying money doesn't make any sense!).
if it is a business then attacking it, exploiting the flaws is dishonest and it may even be pursued legally.
but if it is a cryptocurrency then most of the "attacks" that i see are usually using the features of the coin because it was poorly designed and leads to catastrophe. in any case attacking it won't help with any kind of "overtaking"!

as an arbitrary example this is decent but it should be noted that as a third person looking at a transaction we have no way of knowing which address is the change address and which one belongs to the recipient because there simply is no difference.
in fact to my eyes the 10BTC looks like the change and 0.89 seems like the payment mainly because wallets usually put the change in second output index.

it is the same as repeating $1000 over and over again a couple of months ago at the beginning of 2019 when price was in $3k range and wasn't rising. and its not just that, it is the same as people repeating $50k back in 2017 when price was headed towards $20k.
for some reason these people tend to get stuck and think just because price has moved in a certain direction then it should keep moving in that direction forever!

in modular arithmetic, the numbers in the group defined by p aren't bigger than p, if they were their remainder (mod p) is calculated hence the finite group. if prime was 5 the group is like this:
{0, 1, 2, 3, 4} when we have 5 we calculate its mod prime and put 0 in its place. for 6 we put 1,...

as for y, it is the vertical coordinate of the points on the curve. and -y is not like regular arithmetic where you flip the sign, -y is defined as (prime - y) so that we mirror the point over x axis and find the other point on curve.