No, between 600,000 and 900,000, maybe slightly more. You're thinking of the daily maximum before the Segwit softfork, but that happened several weeks ago.

Bitcoin's already had blocks as large as 1.5 MB since Segwit activated.

You're not getting it


If (post-fork) you send K0 > K1 on BTC chain, and K0 > K2 on B2X chain, what's stopping a replay attacker from swapping those, i.e. broadcasting K0 > K2 on BTC chain and K0 > K1 on B2X chain?


Nothing. You might say "unlikely the replays will confirm", which is why I already said "it depends which transaction the miner who mines those transaction sees first, which is not necessarily going to be your intended transactions with the correct addresses"


What you're suggesting is not guaranteed to fail. But it's not guaranteed to work either, it depends if there's someone out there who's going to cause that kind of chaos. (let's be honest, best not to bet against that).

Ah, interesting. Sounds familiar, I read the BIP173 text pretty quickly

So there is no error correction whatsoever in Satoshi-era types like P2PKH and P2SH? (or even the original type P2PK?)



Upcoming 0.15.1 (which may or may not include waiting for 0.15.0.2 first, achow101 might tell us more)

Edit: Segwit GUI in Bitcoin Core will now be in 0.15.2, 0.15.1 will be bugfixes and backports

02/12/2018 Edit: Segwit wallets will be in the Bitcoin Core 0.16.0 release, very soon

In situations where people don't copy and paste, it helps to reduce the chance of errors.

Even that's not enough.

An automated replay attacker can still broadcast the transactions from the BTC chain and the B2X chain on the opposite chain. There exists a risk that either transaction will confirm on the chain that you don't have the private keys for. It depends which transaction the miner who mines those transaction sees first, which is not necessarily going to be your intended transactions with the correct addresses.

The public key hash for a bech32 address can also be a 256 bit value, but only for P2WSH addresses. These will have a larger number of possible addresses.

• There are 2 different Segwit address formats. They are P2SH (starting with a "3") and bech32 (starting "bc1")
• P2SH can be sent to by people using older Bitcoin software with no Segwit support. This supports backwards compatibility
• People sending from newer Bitcoin software that has Segwit and bech32 can send to the new address type that starts "bc1"
• People sending from older Bitcoin software that has no Segwit probably cannot send to the new address type that starts "bc1"

So, if people send you BTC from old software, give them the Segwit addresses that start with "3". If people send you BTC using new Segwit Bitcoin software, give them the Segwit addresses that start with "bc1".

If you don't know if someone has the newer bech32 software or not, there's no need to worry, their software will simply refuse to send the transaction, so no harm can be done.

• You won't get the Segwit fee reduction unless you spend from one of these addresses
• The addresses starting "3" are normal addresses. They already exist in the Bitcoin blockchain now. The difference is that the Bitcoin script permits a wide variety of options, in this case, using Segwit in a way that old Bitcoin software can handle (obviously old software has no clue what Segwit is, it didn't exist back then, this method works around that)
• The addresses starting "bc1" are not normal addresses. They are brand new, and only work with Segwit
• With addresses starting "bc1", it doesn't matter if you USE UPPER CASE. or if you use lower case. bc1bech32segwitaddressescanbeupperorlowercase is the same address as BC1BECH32SEGWITADDRESSESCANBEUPPERORLOWERCASE, neither your wallet software or the blockchain will care

There are no guarantees. Bitcoin isn't like going to Walmart (where a price is the only price you can get), it's like going to an auction house. The miners control whose transactions they include in blocks, and they can do it any way they like, even totally crazy ways that lose them money.

But, you could expect to pay fees of ~50% less than non-Segwit transactions, for a regular transaction where you pay from just one address to one address (with one change address). Why? Sort of complicated, but I can explain if you like.



No. Old addresses can exist alongside Segwit addresses in the same wallet.

If you're nervous about this, just use a new wallet for all Segwit transactions. But Electrum's approach to wallet specs is flexible enough to allow it, and also the standard way of doing it, it has alot of fail safety built into the design. It should be fine (Disclaimer: I don't use Electrum wallet)

I think that the number of confirmations/blocks for which mined coins are unspendable was changed, but I can't remember exactly by how much or when. Not sure if it affects this analysis, therefore.

The addresses starting with 3 (nested Segwit in a P2SH type) are definitely backwards compatible: older (non-Segwit) wallet software can receive BTC from your P2SH addresses, and they can send to them too.

The addresses starting bc1 (bech32 P2WPKH type) are a new Segwit only type to make addresses easier to use. They essentially make addresess case-insensitive, e.g. BC1MYNEWBITCOINADDRESSISBECH32 is the exact same address as bc1mynewbitcoinaddressisbech32

I'm sure bc1 (bech32 P2WPKH) are backwards compatible at the blockchain level, because they'd need a hard fork to implement them if not, but that doesn't mean that old wallet software will allow you to send BTC to them. Receiving from them using old wallet software may also be a problem, depending on how that specific wallet software is written. But old wallet software may be able to send or receive, to reiterate, it entirely depends on how the software was written.


It's maybe best to think of the 3 (P2SH) addresses as transitional, and the bc1 (bech32 P2WPKH) addresses as better for a post-Segwit situation (i.e. once non-Segwit addresses become atypical for users and businesses)

Explain why this is logical:

1. Increasing the blocksize limit to 4MB in September
2. Blocksize averages between 0.9 MB and 1.1 MB after that (and still does today)
3. Increasing the blocksize limit to 8MB less than 2 months later


That's the "logic" of the Segwit2x "upgrade" right there for you

If the market rejects B2X, the miners will not have an option to do so. Unless they have a very understanding relationship with their electricity supplier, i.e. "please let us have our multi-gigawatt hours of electricity for free"

And it seems that the market will reject B2X, and that your statement is therefore likely to be wrong.

1, no it doesn't, and 2, no it doesn't.

The invisible hand has never operated without interference for long. Whenever regular people should simply learn from their own mistakes, or learn from the mistakes of others, government and the newsmedia step in and start repeating over and over again about how much we need some authority or other "to stop this sort of thing happening". Then, the new authority fails to stop anything, and instead gets people to pay for very expensive high security housing for the transgressors (commonly referred to as "prison"), where criminal attitudes and skills are only consolidated, not reformed.


The "law" is poorly named: it is trivial to break, and therefore not any kind of law at all. That's what makes cryptocurrency (and cryptography in general) superior to man-made rules: breaking the rules of the Bitcoin network (guarded by cryptographic proofs) is next to impossible.


And so the crypto-economy can, and already does, operate on it's own. It's messy, but it's actually the capitalism that people like Adam Smith, Karl Menger and Frederic Bastiat wrote about. Except this brand of cryptographic capitalism is very difficult to interfere with, hence why the top-down authoritarians in government and the finance world are so afraid of it: because this is real capitalism, they will actually have to compete, and they're afraid of a real competition

So, just to reiterate:

• Bitcoin Core team designed Segwit so that it's easy either to use it, or not to use it: a soft-fork that can be chosen by users
• Segwit2x team designed the BTC1 software so that transactions appear on both the Bitcoin network and on the B2X fork, and convinced as many miners as they could to use BTC1, which makes using the original Bitcoin network even more difficult: users are pushed, very strongly, to use a different cryptocurrency, programmed by a totally different team

Everything about that is accurate. If anyone disagrees, prove it.

That's because you're lying. There is nowhere to start, because I'm 100% accurate in what I'm saying.



There are some changes to Bitcoin that can only be made using a hard-fork, and they would be useful and important changes. It's difficult to see how you can come to the conclusion that I dislike hard-forks, I've never said anything like that.

And you, uh, accuse me of distortions and inaccuracies? Interesting.

Seriously, ROFL

1. Someone needs to wake this dinosaur economist up: it's 2017, central bank currencies have been digital since the 1980's

2. Money laundering and tax evasion went the same way as copyright: non-concepts. There's no such thing as copyright anymore, it's been meaningless for a long time.

Bitcoin did the same to money laundering and tax evasion that p2p filesharing did to copyright, there's just no point in pretending un-workable ideas still work.

If people need to target anti-social or immoral behaviour, they need to come up with a better idea. If people running government-owned monopoly service providers can't raise money through violently threatened theft (i.e. taxes), they need to come up with a better idea to do it.

Yep. They did choose Segwit.


The difference is that they consulted and proposed the change to everyone. Not just their friends. And they did nothing to force anyone to use Segwit, if someone doesn't want to use it, they can still use the regular P2PKH and P2SH Bitcoin address formats. This was a deliberate choice in the way Segwit was designed.


Everything about Segwit2X / B2X design, and it's promotional rhetoric, has the effect of imposing their hard fork on Bitcoin users; no proposition, no consulting. And so no opportunity to agree. That's called force.


So, you were saying...?

You obviously don't understand


Jeff Garzik is quoted as essentially saying "B2X is the real Bitcoin, so we don't need to protect users money"


If a Bitcoin hard fork uses the same network parameters as the original Bitcoin (as B2X does), then if Bitcoin Core changed their network parameters to stop tx replays, then Garzik will just change the B2X net parameters in the exact same way to stop Core, using the same logic that "B2X is the real Bitcoin, so we don't need to protect users money".

So, Garzik, Silbert & the miners basically want to choose what Bitcoin is for all users, and yet you're trying to say this is some kind of benevolent or benign act? Tell me you still agree with that, lol

If gold was what gives fiat money it's value (it isn't), then what gives gold it's value?


Don't say electric or chemical properties. The price of gold is far, far too high to be used industrially, save for some very niche applications where the extreme expense of gold can be absorbed.


So, why then is gold so valuable, if it never gets used for the (physical) tasks it can perform so well?

But check out his job title though:



This guy, and by extension NYU, actually believes that using language like "I'm [professionally] ok with this price", or "this price is technically incorrect" is in any way categorically capitalism.


It isn't. I'm ok with people like Damodaran making such pronouncements (), but let's call it what it is: technocratic central planning, or pricing by decree. Which is not capitalism, where capital allocated by it's owners is used to make price determination (it's so simple ffs), however "wrong" that price is.

The capitalist way of viewing this might be described as being only subtly different: one could say that they believe Bitcoin to be overvalued at price x or price y. Subtle or not, the language we use has an important effect on the filters through which we interpret the world around us.

I expect that won't work, Bitpay won't willingly make it easy for Copay users to avoid their hardfork. Best course of action is to export your keys to use with different wallet software, and keep the Copay wallet for when you want to dump your B2X coins when the airdrop happens.

Be careful to follow best practices to avoid replay transactions (maybe if you swap Copay wallet for BTC wallet when making B2X transactions, you could use the replay protection that apparently exists in that software, but it needs to be selected as an option, it's not a default option)