Bitcoin Miner Pro 2018 V 3.2 Free Activation Key ...

Short writeup of the BIP66 disaster. Is this technically not-wrong?

I wrote up the BIP66 disaster. Is this technically not-wrong? Any amusing or important details worth mentioning?
BIP66: secured by math, if we can be bothered
In early July 2015, in the midst of a transaction spam denial-of-service attack, the blockchain forked. Different mining pools were building on different blockchains, and some were adding invalid blocks. Many supposedly-confirmed transactions were being orphaned and thrown away.
The developers had pushed out a small protocol change, BIP66 (Bitcoin Improvement Proposal 66), intended to make signature validation rules stricter.[1] This was designed to switch on at 95% approval – when 950 out of the previous 1000 blocks were mined by software that supported BIP66.
What happened was that miners from two pools, AntPool and F2Pool, advertised that they conformed to BIP66 ... but weren't actually bothering to do so, because that would slow down mining.
It then came out that many miners – about half the total hash rate – had not been verifying the transactions in the current or previous block at all for the past several months, because doing the one thing that's the justification for being awarded bitcoins at all turned out to be too much overhead when you could be mining the next block. Not verifying saved them a whole two seconds. So they just ... assumed the transactions, and other miners’ blocks, were okay![2] Bitcoin core developer Greg Maxwell noted:[3]
Three months ago I discovered a miner with ~1% of the hashrate that was processing transactions with no signature validation at all. If I had sent that miner a transaction where I spent a million of other people’s bitcoins they would have mined it and the half of the non-verifying miners would likely have given it 6+ confirms for any SPV client; and that’s the more fundamental issue here which no amount of version checking would help with.
The Bitcoin protocol doesn’t require that you verify any transactions at all to mine a block. So a lot of miners were also mining completely empty blocks. Because it was faster.
Nobody would do something so damaging, it wouldn’t be in their self-interest. Except when it is, then they’ll do it in a heartbeat.
As this was during a transaction spam attack, the blockchain was clogged anyway; bitcoin.org was recommending people wait 30 blocks (five hours) before assuming their non-spam transaction had in fact gone through.
You know, sometimes I don’t think miners really care about the political power and potential of Bitcoin.
.
[1] Pieter Wuille. “BIP 66: Strict DER signatures”. 10 January 2015. [2] “Some Miners Generating Invalid Blocks”. Bitcoin.org, 4 July 2015. [3] Greg Maxwell (nullc). Comment on “If you are using any wallet other than Bitcoin Core 0.10.x or 0.9.5 (or something backed by one of those versions), then you should not trust incoming transactions until they have ~30 confirmations”. Reddit /bitcoin, 4 July 2015.
submitted by dgerard to Buttcoin [link] [comments]

Bitcoin Core's Peter Todd: 'The problem with mined sidechains is that the segwit "anyone-can-spend" issue is a reality, not FUD, and miners can steal sidechain funds; the reason why segwit doesn't have that problem is because full nodes prevent the theft, but sidechains have only miner-trusting SPV'

Bitcoin Core's Peter Todd: 'The problem with mined sidechains is that the segwit submitted by michelson01 to btc [link] [comments]

SPV, SPY Mining Producing Empty Blocks on Bitcoin and Ethereum

submitted by cryptoallbot1 to cryptoall [link] [comments]

SPV, SPY Mining Producing Empty Blocks on Bitcoin and Ethereum

submitted by cryptoanalyticabot to blockchainanalytics [link] [comments]

Reina Nakamoto: In the Bitcoin Whitepaper a node means a specific thing: It's a mining node. Aka in the Whitepaper, all nodes mined. There was no concept of what BTC community describes as their "validating full nodes (that don't mine)". In WP: There were just mining nodes and SPV wallets.

Reina Nakamoto: In the Bitcoin Whitepaper a node means a specific thing: It's a mining node. Aka in the Whitepaper, all nodes mined. There was no concept of what BTC community describes as their submitted by ABitcoinAllBot to BitcoinAll [link] [comments]

X-post from /r/bitcoin How to disincentivize SPV mining.

X-post from /bitcoin How to disincentivize SPV mining. submitted by testing1567 to bitcoinxt [link] [comments]

Can you mine while connected to the Bitcoin network via SPV client?

I know solo miners typically connect via full nodes.
Pool miners typically report to a pool admin who maintain a full node.
I've heard that people can mine with an SPV client but was wondering if this is true?
For example, I've read that in 2015 miners actually were able to do so with SPV clients due to the blockchain fork IIRC. Do you know how this was possible?
submitted by ecurrencyhodler to btc [link] [comments]

SPV Mining reveals a problematic incentive issue. | Nathan Wilcox | Jul 11 2015 /r/bitcoin_devlist

SPV Mining reveals a problematic incentive issue. | Nathan Wilcox | Jul 11 2015 /bitcoin_devlist submitted by BitcoinAllBot to BitcoinAll [link] [comments]

Can you mine while connected to the Bitcoin network via SPV client? /r/Bitcoin

Can you mine while connected to the Bitcoin network via SPV client? /Bitcoin submitted by BitcoinAllBot to BitcoinAll [link] [comments]

Bitcoin Core's Peter Todd: 'The problem with mined sidechains is that the segwit "anyone-can-spend" issue is a reality, not FUD, and miners can steal sidechain funds; the reason why segwit doesn't have that problem is because full nodes prevent the theft, but sidechains have only miner-trusting SPV'

Bitcoin Core's Peter Todd: 'The problem with mined sidechains is that the segwit submitted by BitcoinAllBot to BitcoinAll [link] [comments]

Can you mine while connected to the Bitcoin network via SPV client?

I know solo miners typically connect via full nodes.
Pool miners typically report to a pool admin who maintain a full node.
I've heard that people can mine with an SPV client but was wondering if this is true?
Are there other ways to connect to the Bitcoin network?
submitted by ecurrencyhodler to BitcoinMining [link] [comments]

Miners are struggling with blocks far smaller than 750KB blocks and resorting to SPV mining | Luv Khemani | Aug 17 2015 /r/bitcoin_devlist

Miners are struggling with blocks far smaller than 750KB blocks and resorting to SPV mining | Luv Khemani | Aug 17 2015 /bitcoin_devlist submitted by BitcoinAllBot to BitcoinAll [link] [comments]

Can you mine while connected to the Bitcoin network via SPV client? /r/BitcoinMining

Can you mine while connected to the Bitcoin network via SPV client? /BitcoinMining submitted by BitcoinAllBot to BitcoinAll [link] [comments]

Can you mine while connected to the Bitcoin network via SPV client? /r/btc

Can you mine while connected to the Bitcoin network via SPV client? /btc submitted by BitcoinAllBot to BitcoinAll [link] [comments]

Technical: Taproot: Why Activate?

This is a follow-up on https://old.reddit.com/Bitcoin/comments/hqzp14/technical_the_path_to_taproot_activation/
Taproot! Everybody wants it!! But... you might ask yourself: sure, everybody else wants it, but why would I, sovereign Bitcoin HODLer, want it? Surely I can be better than everybody else because I swapped XXX fiat for Bitcoin unlike all those nocoiners?
And it is important for you to know the reasons why you, o sovereign Bitcoiner, would want Taproot activated. After all, your nodes (or the nodes your wallets use, which if you are SPV, you hopefully can pester to your wallet vendoimplementor about) need to be upgraded in order for Taproot activation to actually succeed instead of becoming a hot sticky mess.
First, let's consider some principles of Bitcoin.
I'm sure most of us here would agree that the above are very important principles of Bitcoin and that these are principles we would not be willing to remove. If anything, we would want those principles strengthened (especially the last one, financial privacy, which current Bitcoin is only sporadically strong with: you can get privacy, it just requires effort to do so).
So, how does Taproot affect those principles?

Taproot and Your /Coins

Most HODLers probably HODL their coins in singlesig addresses. Sadly, switching to Taproot would do very little for you (it gives a mild discount at spend time, at the cost of a mild increase in fee at receive time (paid by whoever sends to you, so if it's a self-send from a P2PKH or bech32 address, you pay for this); mostly a wash).
(technical details: a Taproot output is 1 version byte + 32 byte public key, while a P2WPKH (bech32 singlesig) output is 1 version byte + 20 byte public key hash, so the Taproot output spends 12 bytes more; spending from a P2WPKH requires revealing a 32-byte public key later, which is not needed with Taproot, and Taproot signatures are about 9 bytes smaller than P2WPKH signatures, but the 32 bytes plus 9 bytes is divided by 4 because of the witness discount, so it saves about 11 bytes; mostly a wash, it increases blockweight by about 1 virtual byte, 4 weight for each Taproot-output-input, compared to P2WPKH-output-input).
However, as your HODLings grow in value, you might start wondering if multisignature k-of-n setups might be better for the security of your savings. And it is in multisignature that Taproot starts to give benefits!
Taproot switches to using Schnorr signing scheme. Schnorr makes key aggregation -- constructing a single public key from multiple public keys -- almost as trivial as adding numbers together. "Almost" because it involves some fairly advanced math instead of simple boring number adding, but hey when was the last time you added up your grocery list prices by hand huh?
With current P2SH and P2WSH multisignature schemes, if you have a 2-of-3 setup, then to spend, you need to provide two different signatures from two different public keys. With Taproot, you can create, using special moon math, a single public key that represents your 2-of-3 setup. Then you just put two of your devices together, have them communicate to each other (this can be done airgapped, in theory, by sending QR codes: the software to do this is not even being built yet, but that's because Taproot hasn't activated yet!), and they will make a single signature to authorize any spend from your 2-of-3 address. That's 73 witness bytes -- 18.25 virtual bytes -- of signatures you save!
And if you decide that your current setup with 1-of-1 P2PKH / P2WPKH addresses is just fine as-is: well, that's the whole point of a softfork: backwards-compatibility; you can receive from Taproot users just fine, and once your wallet is updated for Taproot-sending support, you can send to Taproot users just fine as well!
(P2WPKH and P2WSH -- SegWit v0 -- addresses start with bc1q; Taproot -- SegWit v1 --- addresses start with bc1p, in case you wanted to know the difference; in bech32 q is 0, p is 1)
Now how about HODLers who keep all, or some, of their coins on custodial services? Well, any custodial service worth its salt would be doing at least 2-of-3, or probably something even bigger, like 11-of-15. So your custodial service, if it switched to using Taproot internally, could save a lot more (imagine an 11-of-15 getting reduced from 11 signatures to just 1!), which --- we can only hope! --- should translate to lower fees and better customer service from your custodial service!
So I think we can say, very accurately, that the Bitcoin principle --- that YOU are in control of your money --- can only be helped by Taproot (if you are doing multisignature), and, because P2PKH and P2WPKH remain validly-usable addresses in a Taproot future, will not be harmed by Taproot. Its benefit to this principle might be small (it mostly only benefits multisignature users) but since it has no drawbacks with this (i.e. singlesig users can continue to use P2WPKH and P2PKH still) this is still a nice, tidy win!
(even singlesig users get a minor benefit, in that multisig users will now reduce their blockchain space footprint, so that fees can be kept low for everybody; so for example even if you have your single set of private keys engraved on titanium plates sealed in an airtight box stored in a safe buried in a desert protected by angry nomads riding giant sandworms because you're the frickin' Kwisatz Haderach, you still gain some benefit from Taproot)
And here's the important part: if P2PKH/P2WPKH is working perfectly fine with you and you decide to never use Taproot yourself, Taproot will not affect you detrimentally. First do no harm!

Taproot and Your Contracts

No one is an island, no one lives alone. Give and you shall receive. You know: by trading with other people, you can gain expertise in some obscure little necessity of the world (and greatly increase your productivity in that little field), and then trade the products of your expertise for necessities other people have created, all of you thereby gaining gains from trade.
So, contracts, which are basically enforceable agreements that facilitate trading with people who you do not personally know and therefore might not trust.
Let's start with a simple example. You want to buy some gewgaws from somebody. But you don't know them personally. The seller wants the money, you want their gewgaws, but because of the lack of trust (you don't know them!! what if they're scammers??) neither of you can benefit from gains from trade.
However, suppose both of you know of some entity that both of you trust. That entity can act as a trusted escrow. The entity provides you security: this enables the trade, allowing both of you to get gains from trade.
In Bitcoin-land, this can be implemented as a 2-of-3 multisignature. The three signatories in the multisgnature would be you, the gewgaw seller, and the escrow. You put the payment for the gewgaws into this 2-of-3 multisignature address.
Now, suppose it turns out neither of you are scammers (whaaaat!). You receive the gewgaws just fine and you're willing to pay up for them. Then you and the gewgaw seller just sign a transaction --- you and the gewgaw seller are 2, sufficient to trigger the 2-of-3 --- that spends from the 2-of-3 address to a singlesig the gewgaw seller wants (or whatever address the gewgaw seller wants).
But suppose some problem arises. The seller gave you gawgews instead of gewgaws. Or you decided to keep the gewgaws but not sign the transaction to release the funds to the seller. In either case, the escrow is notified, and if it can sign with you to refund the funds back to you (if the seller was a scammer) or it can sign with the seller to forward the funds to the seller (if you were a scammer).
Taproot helps with this: like mentioned above, it allows multisignature setups to produce only one signature, reducing blockchain space usage, and thus making contracts --- which require multiple people, by definition, you don't make contracts with yourself --- is made cheaper (which we hope enables more of these setups to happen for more gains from trade for everyone, also, moon and lambos).
(technology-wise, it's easier to make an n-of-n than a k-of-n, making a k-of-n would require a complex setup involving a long ritual with many communication rounds between the n participants, but an n-of-n can be done trivially with some moon math. You can, however, make what is effectively a 2-of-3 by using a three-branch SCRIPT: either 2-of-2 of you and seller, OR 2-of-2 of you and escrow, OR 2-of-2 of escrow and seller. Fortunately, Taproot adds a facility to embed a SCRIPT inside a public key, so you can have a 2-of-2 Taprooted address (between you and seller) with a SCRIPT branch that can instead be spent with 2-of-2 (you + escrow) OR 2-of-2 (seller + escrow), which implements the three-branched SCRIPT above. If neither of you are scammers (hopefully the common case) then you both sign using your keys and never have to contact the escrow, since you are just using the escrow public key without coordinating with them (because n-of-n is trivial but k-of-n requires setup with communication rounds), so in the "best case" where both of you are honest traders, you also get a privacy boost, in that the escrow never learns you have been trading on gewgaws, I mean ewww, gawgews are much better than gewgaws and therefore I now judge you for being a gewgaw enthusiast, you filthy gewgawer).

Taproot and Your Contracts, Part 2: Cryptographic Boogaloo

Now suppose you want to buy some data instead of things. For example, maybe you have some closed-source software in trial mode installed, and want to pay the developer for the full version. You want to pay for an activation code.
This can be done, today, by using an HTLC. The developer tells you the hash of the activation code. You pay to an HTLC, paying out to the developer if it reveals the preimage (the activation code), or refunding the money back to you after a pre-agreed timeout. If the developer claims the funds, it has to reveal the preimage, which is the activation code, and you can now activate your software. If the developer does not claim the funds by the timeout, you get refunded.
And you can do that, with HTLCs, today.
Of course, HTLCs do have problems:
Fortunately, with Schnorr (which is enabled by Taproot), we can now use the Scriptless Script constuction by Andrew Poelstra. This Scriptless Script allows a new construction, the PTLC or Pointlocked Timelocked Contract. Instead of hashes and preimages, just replace "hash" with "point" and "preimage" with "scalar".
Or as you might know them: "point" is really "public key" and "scalar" is really a "private key". What a PTLC does is that, given a particular public key, the pointlocked branch can be spent only if the spender reveals the private key of the given public key to you.
Another nice thing with PTLCs is that they are deniable. What appears onchain is just a single 2-of-2 signature between you and the developemanufacturer. It's like a magic trick. This signature has no special watermarks, it's a perfectly normal signature (the pledge). However, from this signature, plus some datta given to you by the developemanufacturer (known as the adaptor signature) you can derive the private key of a particular public key you both agree on (the turn). Anyone scraping the blockchain will just see signatures that look just like every other signature, and as long as nobody manages to hack you and get a copy of the adaptor signature or the private key, they cannot get the private key behind the public key (point) that the pointlocked branch needs (the prestige).
(Just to be clear, the public key you are getting the private key from, is distinct from the public key that the developemanufacturer will use for its funds. The activation key is different from the developer's onchain Bitcoin key, and it is the activation key whose private key you will be learning, not the developer's/manufacturer's onchain Bitcoin key).
So:
Taproot lets PTLCs exist onchain because they enable Schnorr, which is a requirement of PTLCs / Scriptless Script.
(technology-wise, take note that Scriptless Script works only for the "pointlocked" branch of the contract; you need normal Script, or a pre-signed nLockTimed transaction, for the "timelocked" branch. Since Taproot can embed a script, you can have the Taproot pubkey be a 2-of-2 to implement the Scriptless Script "pointlocked" branch, then have a hidden script that lets you recover the funds with an OP_CHECKLOCKTIMEVERIFY after the timeout if the seller does not claim the funds.)

Quantum Quibbles!

Now if you were really paying attention, you might have noticed this parenthetical:
(technical details: a Taproot output is 1 version byte + 32 byte public key, while a P2WPKH (bech32 singlesig) output is 1 version byte + 20 byte public key hash...)
So wait, Taproot uses raw 32-byte public keys, and not public key hashes? Isn't that more quantum-vulnerable??
Well, in theory yes. In practice, they probably are not.
It's not that hashes can be broken by quantum computes --- they're still not. Instead, you have to look at how you spend from a P2WPKH/P2PKH pay-to-public-key-hash.
When you spend from a P2PKH / P2WPKH, you have to reveal the public key. Then Bitcoin hashes it and checks if this matches with the public-key-hash, and only then actually validates the signature for that public key.
So an unconfirmed transaction, floating in the mempools of nodes globally, will show, in plain sight for everyone to see, your public key.
(public keys should be public, that's why they're called public keys, LOL)
And if quantum computers are fast enough to be of concern, then they are probably fast enough that, in the several minutes to several hours from broadcast to confirmation, they have already cracked the public key that is openly broadcast with your transaction. The owner of the quantum computer can now replace your unconfirmed transaction with one that pays the funds to itself. Even if you did not opt-in RBF, miners are still incentivized to support RBF on RBF-disabled transactions.
So the extra hash is not as significant a protection against quantum computers as you might think. Instead, the extra hash-and-compare needed is just extra validation effort.
Further, if you have ever, in the past, spent from the address, then there exists already a transaction indelibly stored on the blockchain, openly displaying the public key from which quantum computers can derive the private key. So those are still vulnerable to quantum computers.
For the most part, the cryptographers behind Taproot (and Bitcoin Core) are of the opinion that quantum computers capable of cracking Bitcoin pubkeys are unlikely to appear within a decade or two.
So:
For now, the homomorphic and linear properties of elliptic curve cryptography provide a lot of benefits --- particularly the linearity property is what enables Scriptless Script and simple multisignature (i.e. multisignatures that are just 1 signature onchain). So it might be a good idea to take advantage of them now while we are still fairly safe against quantum computers. It seems likely that quantum-safe signature schemes are nonlinear (thus losing these advantages).

Summary

I Wanna Be The Taprooter!

So, do you want to help activate Taproot? Here's what you, mister sovereign Bitcoin HODLer, can do!

But I Hate Taproot!!

That's fine!

Discussions About Taproot Activation

submitted by almkglor to Bitcoin [link] [comments]

Technical: The Path to Taproot Activation

Taproot! Everybody wants to have it, somebody wants to make it, nobody knows how to get it!
(If you are asking why everybody wants it, see: Technical: Taproot: Why Activate?)
(Pedants: I mostly elide over lockin times)
Briefly, Taproot is that neat new thing that gets us:
So yes, let's activate taproot!

The SegWit Wars

The biggest problem with activating Taproot is PTSD from the previous softfork, SegWit. Pieter Wuille, one of the authors of the current Taproot proposal, has consistently held the position that he will not discuss activation, and will accept whatever activation process is imposed on Taproot. Other developers have expressed similar opinions.
So what happened with SegWit activation that was so traumatic? SegWit used the BIP9 activation method. Let's dive into BIP9!

BIP9 Miner-Activated Soft Fork

Basically, BIP9 has a bunch of parameters:
Now there are other parameters (name, starttime) but they are not anywhere near as important as the above two.
A number that is not a parameter, is 95%. Basically, activation of a BIP9 softfork is considered as actually succeeding if at least 95% of blocks in the last 2 weeks had the specified bit in the nVersion set. If less than 95% had this bit set before the timeout, then the upgrade fails and never goes into the network. This is not a parameter: it is a constant defined by BIP9, and developers using BIP9 activation cannot change this.
So, first some simple questions and their answers:

The Great Battles of the SegWit Wars

SegWit not only fixed transaction malleability, it also created a practical softforkable blocksize increase that also rebalanced weights so that the cost of spending a UTXO is about the same as the cost of creating UTXOs (and spending UTXOs is "better" since it limits the size of the UTXO set that every fullnode has to maintain).
So SegWit was written, the activation was decided to be BIP9, and then.... miner signalling stalled at below 75%.
Thus were the Great SegWit Wars started.

BIP9 Feature Hostage

If you are a miner with at least 5% global hashpower, you can hold a BIP9-activated softfork hostage.
You might even secretly want the softfork to actually push through. But you might want to extract concession from the users and the developers. Like removing the halvening. Or raising or even removing the block size caps (which helps larger miners more than smaller miners, making it easier to become a bigger fish that eats all the smaller fishes). Or whatever.
With BIP9, you can hold the softfork hostage. You just hold out and refuse to signal. You tell everyone you will signal, if and only if certain concessions are given to you.
This ability by miners to hold a feature hostage was enabled because of the miner-exit allowed by the timeout on BIP9. Prior to that, miners were considered little more than expendable security guards, paid for the risk they take to secure the network, but not special in the grand scheme of Bitcoin.

Covert ASICBoost

ASICBoost was a novel way of optimizing SHA256 mining, by taking advantage of the structure of the 80-byte header that is hashed in order to perform proof-of-work. The details of ASICBoost are out-of-scope here but you can read about it elsewhere
Here is a short summary of the two types of ASICBoost, relevant to the activation discussion.
Now, "overt" means "obvious", while "covert" means hidden. Overt ASICBoost is obvious because nVersion bits that are not currently in use for BIP9 activations are usually 0 by default, so setting those bits to 1 makes it obvious that you are doing something weird (namely, Overt ASICBoost). Covert ASICBoost is non-obvious because the order of transactions in a block are up to the miner anyway, so the miner rearranging the transactions in order to get lower power consumption is not going to be detected.
Unfortunately, while Overt ASICBoost was compatible with SegWit, Covert ASICBoost was not. This is because, pre-SegWit, only the block header Merkle tree committed to the transaction ordering. However, with SegWit, another Merkle tree exists, which commits to transaction ordering as well. Covert ASICBoost would require more computation to manipulate two Merkle trees, obviating the power benefits of Covert ASICBoost anyway.
Now, miners want to use ASICBoost (indeed, about 60->70% of current miners probably use the Overt ASICBoost nowadays; if you have a Bitcoin fullnode running you will see the logs with lots of "60 of last 100 blocks had unexpected versions" which is exactly what you would see with the nVersion manipulation that Overt ASICBoost does). But remember: ASICBoost was, at around the time, a novel improvement. Not all miners had ASICBoost hardware. Those who did, did not want it known that they had ASICBoost hardware, and wanted to do Covert ASICBoost!
But Covert ASICBoost is incompatible with SegWit, because SegWit actually has two Merkle trees of transaction data, and Covert ASICBoost works by fudging around with transaction ordering in a block, and recomputing two Merkle Trees is more expensive than recomputing just one (and loses the ASICBoost advantage).
Of course, those miners that wanted Covert ASICBoost did not want to openly admit that they had ASICBoost hardware, they wanted to keep their advantage secret because miners are strongly competitive in a very tight market. And doing ASICBoost Covertly was just the ticket, but they could not work post-SegWit.
Fortunately, due to the BIP9 activation process, they could hold SegWit hostage while covertly taking advantage of Covert ASICBoost!

UASF: BIP148 and BIP8

When the incompatibility between Covert ASICBoost and SegWit was realized, still, activation of SegWit stalled, and miners were still not openly claiming that ASICBoost was related to non-activation of SegWit.
Eventually, a new proposal was created: BIP148. With this rule, 3 months before the end of the SegWit timeout, nodes would reject blocks that did not signal SegWit. Thus, 3 months before SegWit timeout, BIP148 would force activation of SegWit.
This proposal was not accepted by Bitcoin Core, due to the shortening of the timeout (it effectively times out 3 months before the initial SegWit timeout). Instead, a fork of Bitcoin Core was created which added the patch to comply with BIP148. This was claimed as a User Activated Soft Fork, UASF, since users could freely download the alternate fork rather than sticking with the developers of Bitcoin Core.
Now, BIP148 effectively is just a BIP9 activation, except at its (earlier) timeout, the new rules would be activated anyway (instead of the BIP9-mandated behavior that the upgrade is cancelled at the end of the timeout).
BIP148 was actually inspired by the BIP8 proposal (the link here is a historical version; BIP8 has been updated recently, precisely in preparation for Taproot activation). BIP8 is basically BIP9, but at the end of timeout, the softfork is activated anyway rather than cancelled.
This removed the ability of miners to hold the softfork hostage. At best, they can delay the activation, but not stop it entirely by holding out as in BIP9.
Of course, this implies risk that not all miners have upgraded before activation, leading to possible losses for SPV users, as well as again re-pressuring miners to signal activation, possibly without the miners actually upgrading their software to properly impose the new softfork rules.

BIP91, SegWit2X, and The Aftermath

BIP148 inspired countermeasures, possibly from the Covert ASiCBoost miners, possibly from concerned users who wanted to offer concessions to miners. To this day, the common name for BIP148 - UASF - remains an emotionally-charged rallying cry for parts of the Bitcoin community.
One of these was SegWit2X. This was brokered in a deal between some Bitcoin personalities at a conference in New York, and thus part of the so-called "New York Agreement" or NYA, another emotionally-charged acronym.
The text of the NYA was basically:
  1. Set up a new activation threshold at 80% signalled at bit 4 (vs bit 1 for SegWit).
    • When this 80% signalling was reached, miners would require that bit 1 for SegWit be signalled to achive the 95% activation needed for SegWit.
  2. If the bit 4 signalling reached 80%, increase the block weight limit from the SegWit 4000000 to the SegWit2X 8000000, 6 months after bit 1 activation.
The first item above was coded in BIP91.
Unfortunately, if you read the BIP91, independently of NYA, you might come to the conclusion that BIP91 was only about lowering the threshold to 80%. In particular, BIP91 never mentions anything about the second point above, it never mentions that bit 4 80% threshold would also signal for a later hardfork increase in weight limit.
Because of this, even though there are claims that NYA (SegWit2X) reached 80% dominance, a close reading of BIP91 shows that the 80% dominance was only for SegWit activation, without necessarily a later 2x capacity hardfork (SegWit2X).
This ambiguity of bit 4 (NYA says it includes a 2x capacity hardfork, BIP91 says it does not) has continued to be a thorn in blocksize debates later. Economically speaking, Bitcoin futures between SegWit and SegWit2X showed strong economic dominance in favor of SegWit (SegWit2X futures were traded at a fraction in value of SegWit futures: I personally made a tidy but small amount of money betting against SegWit2X in the futures market), so suggesting that NYA achieved 80% dominance even in mining is laughable, but the NYA text that ties bit 4 to SegWit2X still exists.
Historically, BIP91 triggered which caused SegWit to activate before the BIP148 shorter timeout. BIP148 proponents continue to hold this day that it was the BIP148 shorter timeout and no-compromises-activate-on-August-1 that made miners flock to BIP91 as a face-saving tactic that actually removed the second clause of NYA. NYA supporters keep pointing to the bit 4 text in the NYA and the historical activation of BIP91 as a failed promise by Bitcoin developers.

Taproot Activation Proposals

There are two primary proposals I can see for Taproot activation:
  1. BIP8.
  2. Modern Softfork Activation.
We have discussed BIP8: roughly, it has bit and timeout, if 95% of miners signal bit it activates, at the end of timeout it activates. (EDIT: BIP8 has had recent updates: at the end of timeout it can now activate or fail. For the most part, in the below text "BIP8", means BIP8-and-activate-at-timeout, and "BIP9" means BIP8-and-fail-at-timeout)
So let's take a look at Modern Softfork Activation!

Modern Softfork Activation

This is a more complex activation method, composed of BIP9 and BIP8 as supcomponents.
  1. First have a 12-month BIP9 (fail at timeout).
  2. If the above fails to activate, have a 6-month discussion period during which users and developers and miners discuss whether to continue to step 3.
  3. Have a 24-month BIP8 (activate at timeout).
The total above is 42 months, if you are counting: 3.5 years worst-case activation.
The logic here is that if there are no problems, BIP9 will work just fine anyway. And if there are problems, the 6-month period should weed it out. Finally, miners cannot hold the feature hostage since the 24-month BIP8 period will exist anyway.

PSA: Being Resilient to Upgrades

Software is very birttle.
Anyone who has been using software for a long time has experienced something like this:
  1. You hear a new version of your favorite software has a nice new feature.
  2. Excited, you install the new version.
  3. You find that the new version has subtle incompatibilities with your current workflow.
  4. You are sad and downgrade to the older version.
  5. You find out that the new version has changed your files in incompatible ways that the old version cannot work with anymore.
  6. You tearfully reinstall the newer version and figure out how to get your lost productivity now that you have to adapt to a new workflow
If you are a technically-competent user, you might codify your workflow into a bunch of programs. And then you upgrade one of the external pieces of software you are using, and find that it has a subtle incompatibility with your current workflow which is based on a bunch of simple programs you wrote yourself. And if those simple programs are used as the basis of some important production system, you hve just screwed up because you upgraded software on an important production system.
And well, one of the issues with new softfork activation is that if not enough people (users and miners) upgrade to the newest Bitcoin software, the security of the new softfork rules are at risk.
Upgrading software of any kind is always a risk, and the more software you build on top of the software-being-upgraded, the greater you risk your tower of software collapsing while you change its foundations.
So if you have some complex Bitcoin-manipulating system with Bitcoin somewhere at the foundations, consider running two Bitcoin nodes:
  1. One is a "stable-version" Bitcoin node. Once it has synced, set it up to connect=x.x.x.x to the second node below (so that your ISP bandwidth is only spent on the second node). Use this node to run all your software: it's a stable version that you don't change for long periods of time. Enable txiindex, disable pruning, whatever your software needs.
  2. The other is an "always-up-to-date" Bitcoin Node. Keep its stoarge down with pruning (initially sync it off the "stable-version" node). You can't use blocksonly if your "stable-version" node needs to send transactions, but otherwise this "always-up-to-date" Bitcoin node can be kept as a low-resource node, so you can run both nodes in the same machine.
When a new Bitcoin version comes up, you just upgrade the "always-up-to-date" Bitcoin node. This protects you if a future softfork activates, you will only receive valid Bitcoin blocks and transactions. Since this node has nothing running on top of it, it is just a special peer of the "stable-version" node, any software incompatibilities with your system software do not exist.
Your "stable-version" Bitcoin node remains the same version until you are ready to actually upgrade this node and are prepared to rewrite most of the software you have running on top of it due to version compatibility problems.
When upgrading the "always-up-to-date", you can bring it down safely and then start it later. Your "stable-version" wil keep running, disconnected from the network, but otherwise still available for whatever queries. You do need some system to stop the "always-up-to-date" node if for any reason the "stable-version" goes down (otherwisee if the "always-up-to-date" advances its pruning window past what your "stable-version" has, the "stable-version" cannot sync afterwards), but if you are technically competent enough that you need to do this, you are technically competent enough to write such a trivial monitor program (EDIT: gmax notes you can adjust the pruning window by RPC commands to help with this as well).
This recommendation is from gmaxwell on IRC, by the way.
submitted by almkglor to Bitcoin [link] [comments]

Don't blindly follow a narrative, its bad for you and its bad for crypto in general

I mostly lurk around here but I see a pattern repeating over and over again here and in multiple communities so I have to post. I'm just posting this here because I appreciate the fact that this sub is a place of free speech and maybe something productive can come out from this post, while bitcoin is just fucking censorship, memes and moon/lambo posts. If you don't agree, write in the comments why, instead of downvoting. You don't have to upvote either, but when you downvote you are killing the opportunity to have discussion. If you downvote or comment that I'm wrong without providing any counterpoints you are no better than the BTC maxis you despise.
In various communities I see a narrative being used to bring people in and making them follow something without thinking for themselves. In crypto I see this mostly in BTC vs BCH tribalistic arguments:
- BTC community: "Everything that is not BTC is shitcoin." or more recently as stated by adam on twitter, "Everything that is not BTC is a ponzi scheme, even ETH.", "what is ETH supply?", and even that they are doing this for "altruistic" reasons, to "protect" the newcomers. Very convenient for them that they are protecting the newcomers by having them buy their bags
- BCH community: "BTC maxis are dumb", "just increase block size and you will have truly p2p electronic cash", "It is just that simple, there are no trade offs", "if you don't agree with me you are a BTC maxi", "BCH is satoshi's vision for p2p electronic cash"
It is not exclusive to crypto but also politics, and you see this over and over again on twitter and on reddit.
My point is, that narratives are created so people don't have to think, they just choose a narrative that is easy to follow and makes sense for them, and stick with it. And people keep repeating these narratives to bring other people in, maybe by ignorance, because they truly believe it without questioning, or maybe by self interest, because they want to shill you their bags.
Because this is BCH community, and because bitcoin is censored, so I can't post there about the problems in the BTC narrative (some of which are IMO correctly identified by BCH community), I will stick with the narrative I see in the BCH community.
The culprit of this post was firstly this post by user u/scotty321 "The BTC Paradox: “A 1 MB blocksize enables poor people to run their own node!” “Okay, then what?” “Poor people won’t be able to use the network!”". You will see many posts of this kind being made by u/Egon_1 also. Then you have also this comment in that thread by u/fuck_____________1 saying that people that want to run their own nodes are retarded and that there is no reason to want to do that. "Just trust block explorer websites". And the post and comment were highly upvoted. Really? You really think that there is no problem in having just a few nodes on the network? And that the only thing that secures the network are miners?
As stated by user u/co1nsurf3r in that thread:
While I don't think that everybody needs to run a node, a full node does publish blocks it considers valid to other nodes. This does not amount to much if you only consider a single node in the network, but many "honest" full nodes in the network will reduce the probability of a valid block being withheld from the network by a collusion of "hostile" node operators.
But surely this will not get attention here, and will be downvoted by those people that promote the narrative that there is no trade off in increasing the blocksize and the people that don't see it are retarded or are btc maxis.
The only narrative I stick to and have been for many years now is that cryptocurrency takes power from the government and gives power to the individual, so you are not restricted to your economy as you can participate in the global economy. There is also the narrative of banking the bankless, which I hope will come true, but it is not a use case we are seeing right now.
Some people would argue that removing power from gov's is a bad thing, but you can't deny the fact that gov's can't control crypto (at least we would want them not to).
But, if you really want the individuals to remain in control of their money and transact with anyone in the world, the network needs to be very resistant to any kind of attacks. How can you have p2p electronic cash if your network just has a handful couple of nodes and the chinese gov can locate them and just block communication to them? I'm not saying that this is BCH case, I'm just refuting the fact that there is no value in running your own node. If you are relying on block explorers, the gov can just block the communication to the block explorer websites. Then what? Who will you trust to get chain information? The nodes needs to be decentralized so if you take one node down, many more can appear so it is hard to censor and you don't have few points of failure.
Right now BTC is focusing on that use case of being difficult to censor. But with that comes the problem that is very expensive to transact on the network, which breaks the purpose of anyone being able to participate. Obviously I do think that is also a major problem, and lightning network is awful right now and probably still years away of being usable, if it ever will. The best solution is up for debate, but thinking that you just have to increase the blocksize and there is no trade off is just naive or misleading. BCH is doing a good thing in trying to come with a solution that is inclusive and promotes cheap and fast transactions, but also don't forget centralization is a major concern and nothing to just shrug off.
Saying that "a 1 MB blocksize enables poor people to run their own" and that because of that "Poor people won’t be able to use the network" is a misrepresentation designed to promote a narrative. Because 1MB is not to allow "poor" people to run their node, it is to facilitate as many people to run a node to promote decentralization and avoid censorship.
Also an elephant in the room that you will not see being discussed in either BTC or BCH communities is that mining pools are heavily centralized. And I'm not talking about miners being mostly in china, but also that big pools control a lot of hashing power both in BTC and BCH, and that is terrible for the purpose of crypto.
Other projects are trying to solve that. Will they be successful? I don't know, I hope so, because I don't buy into any narrative. There are many challenges and I want to see crypto succeed as a whole. As always guys, DYOR and always question if you are not blindly following a narrative. I'm sure I will be called BTC maxi but maybe some people will find value in this. Don't trust guys that are always posting silly "gocha's" against the other "tribe".
EDIT: User u/ShadowOfHarbringer has pointed me to some threads that this has been discussed in the past and I will just put my take on them here for visibility, as I will be using this thread as a reference in future discussions I engage:
When there was only 2 nodes in the network, adding a third node increased redundancy and resiliency of the network as a whole in a significant way. When there is thousands of nodes in the network, adding yet another node only marginally increase the redundancy and resiliency of the network. So the question then becomes a matter of personal judgement of how much that added redundancy and resiliency is worth. For the absolutist, it is absolutely worth it and everyone on this planet should do their part.
What is the magical number of nodes that makes it counterproductive to add new nodes? Did he do any math? Does BCH achieve this holy grail safe number of nodes? Guess what, nobody knows at what number of nodes is starts to be marginally irrelevant to add new nodes. Even BTC today could still not have enough nodes to be safe. If you can't know for sure that you are safe, it is better to try to be safer than sorry. Thousands of nodes is still not enough, as I said, it is much cheaper to run a full node as it is to mine. If it costs millions in hash power to do a 51% attack on the block generation it means nothing if it costs less than $10k to run more nodes than there are in total in the network and cause havoc and slowing people from using the network. Or using bot farms to DDoS the 1000s of nodes in the network. Not all attacks are monetarily motivated. When you have governments with billions of dollars at their disposal and something that could threat their power they could do anything they could to stop people from using it, and the cheapest it is to do so the better
You should run a full node if you're a big business with e.g. >$100k/month in volume, or if you run a service that requires high fraud resistance and validation certainty for payments sent your way (e.g. an exchange). For most other users of Bitcoin, there's no good reason to run a full node unless you reel like it.
Shouldn't individuals benefit from fraud resistance too? Why just businesses?
Personally, I think it's a good idea to make sure that people can easily run a full node because they feel like it, and that it's desirable to keep full node resource requirements reasonable for an enthusiast/hobbyist whenever possible. This might seem to be at odds with the concept of making a worldwide digital cash system in which all transactions are validated by everybody, but after having done the math and some of the code myself, I believe that we should be able to have our cake and eat it too.
This is recurrent argument, but also no math provided, "just trust me I did the math"
The biggest reason individuals may want to run their own node is to increase their privacy. SPV wallets rely on others (nodes or ElectronX servers) who may learn their addresses.
It is a reason and valid one but not the biggest reason
If you do it for fun and experimental it good. If you do it for extra privacy it's ok. If you do it to help the network don't. You are just slowing down miners and exchanges.
Yes it will slow down the network, but that shows how people just don't get the the trade off they are doing
I will just copy/paste what Satoshi Nakamoto said in his own words. "The current system where every user is a network node is not the intended configuration for large scale. That would be like every Usenet user runs their own NNTP server."
Another "it is all or nothing argument" and quoting satoshi to try and prove their point. Just because every user doesn't need to be also a full node doesn't mean that there aren't serious risks for having few nodes
For this to have any importance in practice, all of the miners, all of the exchanges, all of the explorers and all of the economic nodes should go rogue all at once. Collude to change consensus. If you have a node you can detect this. It doesn't do much, because such a scenario is impossible in practice.
Not true because as I said, you can DDoS the current nodes or run more malicious nodes than that there currently are, because is cheap to do so
Non-mining nodes don't contribute to adding data to the blockchain ledger, but they do play a part in propagating transactions that aren't yet in blocks (the mempool). Bitcoin client implementations can have different validations for transactions they see outside of blocks and transactions they see inside of blocks; this allows for "soft forks" to add new types of transactions without completely breaking older clients (while a transaction is in the mempool, a node receiving a transaction that's a new/unknown type could drop it as not a valid transaction (not propagate it to its peers), but if that same transaction ends up in a block and that node receives the block, they accept the block (and the transaction in it) as valid (and therefore don't get left behind on the blockchain and become a fork). The participation in the mempool is a sort of "herd immunity" protection for the network, and it was a key talking point for the "User Activated Soft Fork" (UASF) around the time the Segregated Witness feature was trying to be added in. If a certain percentage of nodes updated their software to not propagate certain types of transactions (or not communicate with certain types of nodes), then they can control what gets into a block (someone wanting to get that sort of transaction into a block would need to communicate directly to a mining node, or communicate only through nodes that weren't blocking that sort of transaction) if a certain threshold of nodes adheres to those same validation rules. It's less specific than the influence on the blockchain data that mining nodes have, but it's definitely not nothing.
The first reasonable comment in that thread but is deep down there with only 1 upvote
The addition of non-mining nodes does not add to the efficiency of the network, but actually takes away from it because of the latency issue.
That is true and is actually a trade off you are making, sacrificing security to have scalability
The addition of non-mining nodes has little to no effect on security, since you only need to destroy mining ones to take down the network
It is true that if you destroy mining nodes you take down the network from producing new blocks (temporarily), even if you have a lot of non mining nodes. But, it still better than if you take down the mining nodes who are also the only full nodes. If the miners are not the only full nodes, at least you still have full nodes with the blockchain data so new miners can download it and join. If all the miners are also the full nodes and you take them down, where will you get all the past blockchain data to start mining again? Just pray that the miners that were taken down come back online at some point in the future?
The real limiting factor is ISP's: Imagine a situation where one service provider defrauds 4000 different nodes. Did the excessive amount of nodes help at all, when they have all been defrauded by the same service provider? If there are only 30 ISP's in the world, how many nodes do we REALLY need?
You cant defraud if the connection is encrypted. Use TOR for example, it is hard for ISP's to know what you are doing.
Satoshi specifically said in the white paper that after a certain point, number of nodes needed plateaus, meaning after a certain point, adding more nodes is actually counterintuitive, which we also demonstrated. (the latency issue). So, we have adequately demonstrated why running non-mining nodes does not add additional value or security to the network.
Again, what is the number of nodes that makes it counterproductive? Did he do any math?
There's also the matter of economically significant nodes and the role they play in consensus. Sure, nobody cares about your average joe's "full node" where he is "keeping his own ledger to keep the miners honest", as it has no significance to the economy and the miners couldn't give a damn about it. However, if say some major exchanges got together to protest a miner activated fork, they would have some protest power against that fork because many people use their service. Of course, there still needs to be miners running on said "protest fork" to keep the chain running, but miners do follow the money and if they got caught mining a fork that none of the major exchanges were trading, they could be coaxed over to said "protest fork".
In consensus, what matters about nodes is only the number, economical power of the node doesn't mean nothing, the protocol doesn't see the net worth of the individual or organization running that node.
Running a full node that is not mining and not involved is spending or receiving payments is of very little use. It helps to make sure network traffic is broadcast, and is another copy of the blockchain, but that is all (and is probably not needed in a healthy coin with many other nodes)
He gets it right (broadcasting transaction and keeping a copy of the blockchain) but he dismisses the importance of it
submitted by r0bo7 to btc [link] [comments]

[ Bitcoin ] Technical: Taproot: Why Activate?

Topic originally posted in Bitcoin by almkglor [link]
This is a follow-up on https://old.reddit.com/Bitcoin/comments/hqzp14/technical_the_path_to_taproot_activation/
Taproot! Everybody wants it!! But... you might ask yourself: sure, everybody else wants it, but why would I, sovereign Bitcoin HODLer, want it? Surely I can be better than everybody else because I swapped XXX fiat for Bitcoin unlike all those nocoiners?
And it is important for you to know the reasons why you, o sovereign Bitcoiner, would want Taproot activated. After all, your nodes (or the nodes your wallets use, which if you are SPV, you hopefully can pester to your wallet vendoimplementor about) need to be upgraded in order for Taproot activation to actually succeed instead of becoming a hot sticky mess.
First, let's consider some principles of Bitcoin.
I'm sure most of us here would agree that the above are very important principles of Bitcoin and that these are principles we would not be willing to remove. If anything, we would want those principles strengthened (especially the last one, financial privacy, which current Bitcoin is only sporadically strong with: you can get privacy, it just requires effort to do so).
So, how does Taproot affect those principles?

Taproot and Your /Coins

Most HODLers probably HODL their coins in singlesig addresses. Sadly, switching to Taproot would do very little for you (it gives a mild discount at spend time, at the cost of a mild increase in fee at receive time (paid by whoever sends to you, so if it's a self-send from a P2PKH or bech32 address, you pay for this); mostly a wash).
(technical details: a Taproot output is 1 version byte + 32 byte public key, while a P2WPKH (bech32 singlesig) output is 1 version byte + 20 byte public key hash, so the Taproot output spends 12 bytes more; spending from a P2WPKH requires revealing a 32-byte public key later, which is not needed with Taproot, and Taproot signatures are about 9 bytes smaller than P2WPKH signatures, but the 32 bytes plus 9 bytes is divided by 4 because of the witness discount, so it saves about 11 bytes; mostly a wash, it increases blockweight by about 1 virtual byte, 4 weight for each Taproot-output-input, compared to P2WPKH-output-input).
However, as your HODLings grow in value, you might start wondering if multisignature k-of-n setups might be better for the security of your savings. And it is in multisignature that Taproot starts to give benefits!
Taproot switches to using Schnorr signing scheme. Schnorr makes key aggregation -- constructing a single public key from multiple public keys -- almost as trivial as adding numbers together. "Almost" because it involves some fairly advanced math instead of simple boring number adding, but hey when was the last time you added up your grocery list prices by hand huh?
With current P2SH and P2WSH multisignature schemes, if you have a 2-of-3 setup, then to spend, you need to provide two different signatures from two different public keys. With Taproot, you can create, using special moon math, a single public key that represents your 2-of-3 setup. Then you just put two of your devices together, have them communicate to each other (this can be done airgapped, in theory, by sending QR codes: the software to do this is not even being built yet, but that's because Taproot hasn't activated yet!), and they will make a single signature to authorize any spend from your 2-of-3 address. That's 73 witness bytes -- 18.25 virtual bytes -- of signatures you save!
And if you decide that your current setup with 1-of-1 P2PKH / P2WPKH addresses is just fine as-is: well, that's the whole point of a softfork: backwards-compatibility; you can receive from Taproot users just fine, and once your wallet is updated for Taproot-sending support, you can send to Taproot users just fine as well!
(P2WPKH and P2WSH -- SegWit v0 -- addresses start with bc1q; Taproot -- SegWit v1 --- addresses start with bc1p, in case you wanted to know the difference; in bech32 q is 0, p is 1)
Now how about HODLers who keep all, or some, of their coins on custodial services? Well, any custodial service worth its salt would be doing at least 2-of-3, or probably something even bigger, like 11-of-15. So your custodial service, if it switched to using Taproot internally, could save a lot more (imagine an 11-of-15 getting reduced from 11 signatures to just 1!), which --- we can only hope! --- should translate to lower fees and better customer service from your custodial service!
So I think we can say, very accurately, that the Bitcoin principle --- that YOU are in control of your money --- can only be helped by Taproot (if you are doing multisignature), and, because P2PKH and P2WPKH remain validly-usable addresses in a Taproot future, will not be harmed by Taproot. Its benefit to this principle might be small (it mostly only benefits multisignature users) but since it has no drawbacks with this (i.e. singlesig users can continue to use P2WPKH and P2PKH still) this is still a nice, tidy win!
(even singlesig users get a minor benefit, in that multisig users will now reduce their blockchain space footprint, so that fees can be kept low for everybody; so for example even if you have your single set of private keys engraved on titanium plates sealed in an airtight box stored in a safe buried in a desert protected by angry nomads riding giant sandworms because you're the frickin' Kwisatz Haderach, you still gain some benefit from Taproot)
And here's the important part: if P2PKH/P2WPKH is working perfectly fine with you and you decide to never use Taproot yourself, Taproot will not affect you detrimentally. First do no harm!

Taproot and Your Contracts

No one is an island, no one lives alone. Give and you shall receive. You know: by trading with other people, you can gain expertise in some obscure little necessity of the world (and greatly increase your productivity in that little field), and then trade the products of your expertise for necessities other people have created, all of you thereby gaining gains from trade.
So, contracts, which are basically enforceable agreements that facilitate trading with people who you do not personally know and therefore might not trust.
Let's start with a simple example. You want to buy some gewgaws from somebody. But you don't know them personally. The seller wants the money, you want their gewgaws, but because of the lack of trust (you don't know them!! what if they're scammers??) neither of you can benefit from gains from trade.
However, suppose both of you know of some entity that both of you trust. That entity can act as a trusted escrow. The entity provides you security: this enables the trade, allowing both of you to get gains from trade.
In Bitcoin-land, this can be implemented as a 2-of-3 multisignature. The three signatories in the multisgnature would be you, the gewgaw seller, and the escrow. You put the payment for the gewgaws into this 2-of-3 multisignature address.
Now, suppose it turns out neither of you are scammers (whaaaat!). You receive the gewgaws just fine and you're willing to pay up for them. Then you and the gewgaw seller just sign a transaction --- you and the gewgaw seller are 2, sufficient to trigger the 2-of-3 --- that spends from the 2-of-3 address to a singlesig the gewgaw seller wants (or whatever address the gewgaw seller wants).
But suppose some problem arises. The seller gave you gawgews instead of gewgaws. Or you decided to keep the gewgaws but not sign the transaction to release the funds to the seller. In either case, the escrow is notified, and if it can sign with you to refund the funds back to you (if the seller was a scammer) or it can sign with the seller to forward the funds to the seller (if you were a scammer).
Taproot helps with this: like mentioned above, it allows multisignature setups to produce only one signature, reducing blockchain space usage, and thus making contracts --- which require multiple people, by definition, you don't make contracts with yourself --- is made cheaper (which we hope enables more of these setups to happen for more gains from trade for everyone, also, moon and lambos).
(technology-wise, it's easier to make an n-of-n than a k-of-n, making a k-of-n would require a complex setup involving a long ritual with many communication rounds between the n participants, but an n-of-n can be done trivially with some moon math. You can, however, make what is effectively a 2-of-3 by using a three-branch SCRIPT: either 2-of-2 of you and seller, OR 2-of-2 of you and escrow, OR 2-of-2 of escrow and seller. Fortunately, Taproot adds a facility to embed a SCRIPT inside a public key, so you can have a 2-of-2 Taprooted address (between you and seller) with a SCRIPT branch that can instead be spent with 2-of-2 (you + escrow) OR 2-of-2 (seller + escrow), which implements the three-branched SCRIPT above. If neither of you are scammers (hopefully the common case) then you both sign using your keys and never have to contact the escrow, since you are just using the escrow public key without coordinating with them (because n-of-n is trivial but k-of-n requires setup with communication rounds), so in the "best case" where both of you are honest traders, you also get a privacy boost, in that the escrow never learns you have been trading on gewgaws, I mean ewww, gawgews are much better than gewgaws and therefore I now judge you for being a gewgaw enthusiast, you filthy gewgawer).

Taproot and Your Contracts, Part 2: Cryptographic Boogaloo

Now suppose you want to buy some data instead of things. For example, maybe you have some closed-source software in trial mode installed, and want to pay the developer for the full version. You want to pay for an activation code.
This can be done, today, by using an HTLC. The developer tells you the hash of the activation code. You pay to an HTLC, paying out to the developer if it reveals the preimage (the activation code), or refunding the money back to you after a pre-agreed timeout. If the developer claims the funds, it has to reveal the preimage, which is the activation code, and you can now activate your software. If the developer does not claim the funds by the timeout, you get refunded.
And you can do that, with HTLCs, today.
Of course, HTLCs do have problems:
Fortunately, with Schnorr (which is enabled by Taproot), we can now use the Scriptless Script constuction by Andrew Poelstra. This Scriptless Script allows a new construction, the PTLC or Pointlocked Timelocked Contract. Instead of hashes and preimages, just replace "hash" with "point" and "preimage" with "scalar".
Or as you might know them: "point" is really "public key" and "scalar" is really a "private key". What a PTLC does is that, given a particular public key, the pointlocked branch can be spent only if the spender reveals the private key of the given private key to you.
Another nice thing with PTLCs is that they are deniable. What appears onchain is just a single 2-of-2 signature between you and the developemanufacturer. It's like a magic trick. This signature has no special watermarks, it's a perfectly normal signature (the pledge). However, from this signature, plus some datta given to you by the developemanufacturer (known as the adaptor signature) you can derive the private key of a particular public key you both agree on (the turn). Anyone scraping the blockchain will just see signatures that look just like every other signature, and as long as nobody manages to hack you and get a copy of the adaptor signature or the private key, they cannot get the private key behind the public key (point) that the pointlocked branch needs (the prestige).
(Just to be clear, the public key you are getting the private key from, is distinct from the public key that the developemanufacturer will use for its funds. The activation key is different from the developer's onchain Bitcoin key, and it is the activation key whose private key you will be learning, not the developer's/manufacturer's onchain Bitcoin key).
So:
Taproot lets PTLCs exist onchain because they enable Schnorr, which is a requirement of PTLCs / Scriptless Script.
(technology-wise, take note that Scriptless Script works only for the "pointlocked" branch of the contract; you need normal Script, or a pre-signed nLockTimed transaction, for the "timelocked" branch. Since Taproot can embed a script, you can have the Taproot pubkey be a 2-of-2 to implement the Scriptless Script "pointlocked" branch, then have a hidden script that lets you recover the funds with an OP_CHECKLOCKTIMEVERIFY after the timeout if the seller does not claim the funds.)

Quantum Quibbles!

Now if you were really paying attention, you might have noticed this parenthetical:
(technical details: a Taproot output is 1 version byte + 32 byte public key, while a P2WPKH (bech32 singlesig) output is 1 version byte + 20 byte public key hash...)
So wait, Taproot uses raw 32-byte public keys, and not public key hashes? Isn't that more quantum-vulnerable??
Well, in theory yes. In practice, they probably are not.
It's not that hashes can be broken by quantum computes --- they're still not. Instead, you have to look at how you spend from a P2WPKH/P2PKH pay-to-public-key-hash.
When you spend from a P2PKH / P2WPKH, you have to reveal the public key. Then Bitcoin hashes it and checks if this matches with the public-key-hash, and only then actually validates the signature for that public key.
So an unconfirmed transaction, floating in the mempools of nodes globally, will show, in plain sight for everyone to see, your public key.
(public keys should be public, that's why they're called public keys, LOL)
And if quantum computers are fast enough to be of concern, then they are probably fast enough that, in the several minutes to several hours from broadcast to confirmation, they have already cracked the public key that is openly broadcast with your transaction. The owner of the quantum computer can now replace your unconfirmed transaction with one that pays the funds to itself. Even if you did not opt-in RBF, miners are still incentivized to support RBF on RBF-disabled transactions.
So the extra hash is not as significant a protection against quantum computers as you might think. Instead, the extra hash-and-compare needed is just extra validation effort.
Further, if you have ever, in the past, spent from the address, then there exists already a transaction indelibly stored on the blockchain, openly displaying the public key from which quantum computers can derive the private key. So those are still vulnerable to quantum computers.
For the most part, the cryptographers behind Taproot (and Bitcoin Core) are of the opinion that quantum computers capable of cracking Bitcoin pubkeys are unlikely to appear within a decade or two.
So:
For now, the homomorphic and linear properties of elliptic curve cryptography provide a lot of benefits --- particularly the linearity property is what enables Scriptless Script and simple multisignature (i.e. multisignatures that are just 1 signature onchain). So it might be a good idea to take advantage of them now while we are still fairly safe against quantum computers. It seems likely that quantum-safe signature schemes are nonlinear (thus losing these advantages).

Summary

I Wanna Be The Taprooter!

So, do you want to help activate Taproot? Here's what you, mister sovereign Bitcoin HODLer, can do!

But I Hate Taproot!!

That's fine!

Discussions About Taproot Activation

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submitted by anticensor_bot to u/anticensor_bot [link] [comments]

Bitcoin Worth Nearly $450 Million Moves For 25 Cents

Bitcoin Worth Nearly $450 Million Moves For 25 Cents submitted by bitbull_capital to Bitcoin [link] [comments]

The Bitcoin Conspiracy (an enthusiast's perspective)

I keep coming across comments, especially in this sub, from people claiming that Bitcoin was created by the CIA or some government agency as part of the plan for the NWO and cashless society. I want to share my experience and try to clear up the confusion surrounding this topic.
I first got involved with Bitcoin in late 2016 when I heard about it and got some while at a libertarian festival. Back then it was still very popular among the agorist community and was being promoted as THE silver bullet that was going to disrupt the global fiat banking system.
Putting preconceptions aside, a new user might ask, "what's so special about Bitcoin? We already have digital currencies."
Well, you only need to read the first page of the whitepaper to discover what the original intent of Bitcoin was. It most definitely was not intended to be a tool for central banks to subjugate the world to a centralized global currency. Quite the opposite in fact. Read the full whitepaper here.
When I first learned about Bitcoin, it forced me to learn about economics, then the Federal Reserve, then one by one the dominoes fell and down the conspiracy rabbit hole I went. In 2017 (actually it started a few years earlier, but I wasn't paying attention back then) there was a very heated debate in the Bitcoin community regarding scaling.
I'll try to break it down simply:
In the very early days, when Bitcoin was just a project being worked on by a few very technical people, no one knew about it. All it took was a handful of people running the software on their laptops to mine new coins. Since there was not much computing power on the network, it meant there could easily be a spam attack where a malicious user could join the network and generate many gigabytes of spam transactions that would overload and crash the network. To prevent this, Satoshi implemented a limit of 1MB per block, to protect the network until there was enough computing power to be able to handle larger blocks.
This measure worked, and Bitcoin grew exponentially.
Satoshi vanished in 2010, after WikiLeaks attracted unwanted attention to the project by accepting Bitcoin donations. He left clear instructions for his successors that the 1MB block size limit was meant to be increased once the network could support high levels of user traffic. At the time, there still was not much use, so it wasn't until around 2014 that blocks started hitting the 1MB cap and all of a sudden users had to compete (by paying higher transaction fees) in order to get their transaction mined into the next block.
Up until then, sending a Bitcoin transaction would cost $0.0001 (hundredth of a penny) or less, no matter if you were sending $0.10 or $1,000,000. Now, since block space was limited, fees started to rise, as miners would only include the transactions with the highest fees. Over the next couple years, transaction fees went up dramatically, at times reaching as high as $100 to send a single transaction.
The solution was obvious - raise the block size limit.
But this led to a heated debate, and this is where the conspiracy became obvious to those who were paying attention. Since Bitcoin was decentralized and open source, anyone could contribute, but certain people controlled the commit access to the github repo, and it became apparent that those individuals had been compromised, as any and all mention of increasing the block size was met with fierce resistance.
There was a misinformation campaign to discredit anyone arguing for larger blocks. The argument was that larger blocks would mean users could not run the software on their low-power personal devices and laptops; that by increasing the block size it would lead to mining centralization. Well, if you read the whitepaper linked above, you'll see that Satoshi predicted this. He knew mining would eventually be left to "specialized server farms" while normal users could use what he termed Simplified Payment Verification (SPV) wallets.
But this point was consistently shot down in the community, and especially on /bitcoin. There was a MASSIVE censorship campaign in the bitcoin subreddit that continues to this day where anyone who questions the official narrative or even asks a basic technical question is immediately banned. /bitcoin today is nothing but a cesspit of price memes and misinformation. Go to /btc for the uncensored discussions (but beware of trolls).
In 2017 the debate was finally settled, sort of. Now known as "Bitcoin Core" (the name of the official Bitcoin software), the developers implemented a change known as SegWit (Segregated Witness) which fundamentally altered the way the software validates transactions. It was implemented as a "soft fork" rather than a "hard fork".
I'll explain the difference.
In a fork, the network comes to a consensus on new rules that all participants must follow. In a hard fork, the changes are non-backwards compatible, so all users must update their software or else be left behind on a dead network. Hard forks happen all the time in software development, but in the case of SegWit, the developers refused to make any non-backwards compatible changes for fear it might alienate users. Again, another unfounded fear. "We can't ever upgrade the technical capabilities of the network (such as the block size) because some people might not go along with it."
All kinds of mental gymnastics were performed to justify their refusal to increase the block size, and there was nothing anyone could do about it except fork as an independent project. The 1MB block limit is now essentially set in stone for BTC. So in August 2017, Bitcoin Cash (BCH) hard forked by increasing the block size limit to 8MB, along with some other changes.
Fast forward to December 2017 and Bitcoin was at its all time high of nearly $20,000. But fees were also astronomical and because of the 1MB block size limit, a huge backlog formed, and some people had to wait days or even weeks for their transaction to confirm. If anyone was trying to cash out into fiat and didn't want to pay a $100 transaction fee, by the time their transaction got confirmed the price had already crashed.
This event was largely responsible for the bear market of 2018. Everything that happened was predicted by those who knew what was going on.
A company called Blockstream had essentially wrestled control of Bitcoin from the original developers and shut them out or gained control over them, and started working on turning Bitcoin into a settlement layer for their product called Lightning Network.
LN is a complicated topic that I don't want to get into, but essentially it's a framework that recreates all the same problems inherent in the banking system that Bitcoin was meant to solve. Blockstream's goal is to profit from creating, and then "solving" those problems by charging users fees for all kinds of custodial services.
In my personal opinion, it's obvious that the original Bitcoin project has been hijacked and repurposed into a tool for the central banks. The propaganda is being pushed in some conspiracy circles that Bitcoin was created BY the central banks in order to discourage people from researching the true history. What is now commonly called "Bitcoin" is not the original project, but a Trojan horse.
The project that most closely follows the original design is Bitcoin Cash, and that is where almost all organic development is happening, and personally I feel that it's picking up steam lately as more people wake up to what's happening in the economy right now. Unfortunately most people are still unaware of how fundamentally broken BTC is now and so as new users run toward cryptocurrency to escape the dollar collapse, most will fall straight into the trap and be stuck with BTC that they won't be able to use without paying exorbitant fees and/or submitting to the very same tracking system they are trying to get away from.
This is a very deep rabbit hole but I think I've written enough for now. I hope this info helps people make sense of what's going on with Bitcoin. I know it's confusing enough even without so much deception taking place so hopefully this helps.
Read the Bitcoin FAQ over on /btc.
submitted by PM_ME_YOUR_ALTCOINS to conspiracy [link] [comments]

If you operate a node please update ASAP! Only 18% of nodes are compatible with November upgrade

submitted by GeorgAnarchist to btc [link] [comments]

So increase your blocksize or something...

So increase your blocksize or something... submitted by vitriolic_amalgamati to btc [link] [comments]

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Is was Wednesday, March 26, 2014. It was a cold winter outside, but not inside an old building of the Princeton university campus. The room, full of people, was warm. I was standing in front of some of the brightest minds in Bitcoin: Andresen, Bonneau, Eyal, Maxwell, Miller, Gün Sirer, Szabo, Todd and Zooko, to name only a few. My talk was about "SPV Mining",… SPV Mining / Old Bitcoin Core The following pools are known or strongly suspected to be mining on top of blocks before fully validating them with Bitcoin Core 0.9.5 or later. Miners doing this have already lost over $50,000 USD during the 4 July 2015 fork and have created a situation where small numbers of confirmations are much less useful ... One look at bitcoin’s blockchain will tell you this is a process that can take a while, and it’s expensive to boot. SPV, on the other hand, just checks to see if the transaction has been verified by a miner and it turns up on a block in the chain. It’s not quite as trustworthy as a full check. - Generate Bitcoin With Bitcoin Miner Pro 2018 V 3.2 9 01:50 Bitcoin Miner Pro 2018 V 3 2 - Bitcoin Miner Pro 2018 %100 Workin Legal With Proof 10 03:53 Bitcoin Miner Pro 2018 V 3 2 - Free Bitcoin Miner 2017/2018 11 04:36 Bitcoin Miner Pro 2018 V 3 2 - New Mining 0.001 Btc In 40 Minutes Blockchain Miner Pro Update New Version 2018 12 02:38 ... Bitcoin SPV wallet client . There are some wallets on GitHub which called themself Bitcoin SPV wallet client. Native Bitcoin SPV client, but it is still experimental and you do not want to use it in production environments today, as developers written at GitHub. BitcoinSPV is still a work-in-progress and will eventually undergo huge modifications.

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To SPV or not to SPV? That is the Bitcoin question

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