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19 votes
Accepted

Why is coinbase mentioned in a BIP?

The coinbase mentioned in BIP34 is not the company; it is referring to the first transaction in a Bitcoin block (which is special as it is allowed to bring new currency into circulation). Coinbase-the-...
Pieter Wuille's user avatar
18 votes
Accepted

Is there a reason to why Bitcoin Core does not implement BIP39?

BIP 39 is not in Bitcoin Core largely for implementation reasons and because BIP 39 is not as secure as it could be. The structure of Bitcoin Core's wallet doesn't really allow for BIP 39 to be ...
Ava Chow's user avatar
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15 votes
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Schnorr's batch validation

You're right that the elliptic curve multiplication is indeed the most expensive operation in the validation algorithm. And as both single signature validation and batch validation require two EC ...
Pieter Wuille's user avatar
13 votes
Accepted

Where are BIPs 40 and 41?

The stratum protocol existed for a while before BIP numbers were eventually assigned. Presumably there was some discussion that they should have BIPs and so BIP numbers were assigned. Stratum started ...
Ava Chow's user avatar
  • 70k
11 votes
Accepted

BIP44: What's the use of internal addresses?

The separation between internal and external addresses comes from BIP32. Using a different chain for each permits you to give out an xpub for just the external ones to an auditor. They would then be ...
Pieter Wuille's user avatar
10 votes
Accepted

Is there an active list of BIPs currently open for voting?

This question is based on a misconception. Miners do not vote on proposals. Consensus changes to Bitcoin are made by the entire ecosystem transitioning to new rules that they choose, by running node ...
Pieter Wuille's user avatar
9 votes
Accepted

What are the different upgradeability features in the BIP-Taproot (BIP 341) proposal?

There is the annex, leaf version, ext_flag, OP_SUCCESS, unknown pubkey types and you could probably include the existing witness version too. I believe that list is exhaustive. The ext_flag isn't so ...
Michael Folkson's user avatar
8 votes
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Is Bitcoin PoW actually SHA256 + Merkle generation? Or have I misunderstood coinbase/append?

You are correct that effectively Bitcoin PoW involves computing the Merkle root every now and then in addition to the hash grinding. However, this is negligable. Even ignoring nTime rolling, the ...
Pieter Wuille's user avatar
8 votes
Accepted

How does a miner put his vote for certain BIP?

See my answer here to address some of your misconceptions. TL;DR: miners signal support in blocks for certain rule changes in order to coordinate activation, not to determine whether it is accepted or ...
Pieter Wuille's user avatar
7 votes
Accepted

BIP 65 - how standard is it?

The softfork defined by BIP 65 activated in december 2015. This means that the whole network enforces the new rules proposed by BIP 65, and it is safe to use CLTV opcodes in scripts since then.
Pieter Wuille's user avatar
7 votes
Accepted

Is every BIP actually a small fork?

Not every BIP is a fork (change in consensus rules). Some are standards for wallet software (like BIP32 and BIP39), the peer-to-peer protocol (BIP152) and other areas. The BIP repository classifies a ...
Vojtěch Strnad's user avatar
6 votes
Accepted

How does nSequence/Check Sequence Verify work?

In order to use a relative time lock, you need to provide the requirements in the scriptPubKey to which the Bitcoin is sent. Example scriptPubKey for escrow with 30 day timeout: IF 2 <Alice's ...
JBaczuk's user avatar
  • 7,368
6 votes

What are the major technical differences between Bitcoin and Bitcoin Cash?

Bitcoin Has SegWit and it's benefits and costs: Code complexity (of acceptable amount) Witness data is discounted in SegWit transactions, somewhat rectifying the fact that outputs are cheaper to ...
6 votes
Accepted

Why is the bitcoin client still in beta

Bitcoin Core probably will never have a "1.0". 1.0 is a socially significant number which indicates some kind of finality or completeness (at least initially). This itself is holding back ...
Ava Chow's user avatar
  • 70k
6 votes

How many BIPs were adopted in the standard client in 2021?

BIPs are just proposals. Whether any particular piece of software supports/adopts it is up to the developers of that software. To find out which BIPs are supported by Bitcoin Core specifically, look ...
Pieter Wuille's user avatar
5 votes

Why seed from BIP39 mnemonic phrase is much longer than entropy?

This is specified in BIP 39 itself: To create a binary seed from the mnemonic, we use the PBKDF2 function with a mnemonic sentence (in UTF-8 NFKD) used as the password and the string "mnemonic" + ...
Nate Eldredge's user avatar
5 votes

Why does the median-past time average the last 11 block timestamps and not the last 12?

BIP 113's goal is not to aim for a specific offset. Its goal is guaranteeing monotonicity (treating every block's timestamp as strictly larger than the timestamp of each of its ancestors). It does ...
Pieter Wuille's user avatar
5 votes
Accepted

BIP91 is activated, why BIP141 is still dormant?

BIP9 only describes a new deployment method of softforks to the Bitcoin network. I therefore assume that you mean the deployment of BIP141 by method of BIP9. The deployment of segwit requires 95% of ...
Murch's user avatar
  • 74.5k
5 votes
Accepted

How to compute double sha256 shown in examples of bip 143?

Do this: echo -n $PREV_OUT | xxd -r -p | openssl dgst -sha256 -binary | openssl dgst -sha256 Explanation You want to do this: prevout (raw bytes) -> sha256 -> sha256 -> convert to hex You're ...
Nick ODell's user avatar
  • 29.4k
5 votes
Accepted

are checksums included in mnemonic seed phrases?

I am assuming that you are talking about BIP 39 here. A BIP 39 mnemonic can have any number of words with the most common being 12, 18, and 24 words. There is a checksum encoded into this mnemonic. ...
Ava Chow's user avatar
  • 70k
5 votes
Accepted

How do BIP numbers get assigned?

The current BIP process is defined in BIP-2. An author drafting a new BIP leaves the BIP number in the preamble marked as XXXX. A BIP editor assigns a number to that BIP when the draft phase is ...
0xb10c's user avatar
  • 1,400
5 votes
Accepted

Criteria for Bitcoin protocol consolidation/freezing at the network level (full nodes)

I think you have a sense of the general idea, but I want to first address a few misunderstandings point by point first. Anyone can submit a BIP that aims to change Bitcoin Core Bitcoin Improvement ...
Murch's user avatar
  • 74.5k
5 votes

What is this || notation in BIP 341?

The meaning of the two pipes is explained in BIP340: || refers to byte array concatenation. The tags for the various tree elements are repeated to amount to 64 bytes. The doubling allows the first ...
Murch's user avatar
  • 74.5k
4 votes

BIP deterministic seeds, number of words and compatible wallets

AFAIK, the two most common sets of HD wallet mnemonic seeds used are BIP 39 compliant or Electrum Wallet compliant. Most of the more secure hardware HD wallet devices support the BIP 39 standard, ...
skaht's user avatar
  • 3,047
4 votes
Accepted

Should full node provide BIP 157/158 services?

Of the 18 outbound connections, one is to a peer which offers COMPACT_FILTERS BIP 158 service. (I got the name from a list of optional node services provided here in Dec. 2019.) And here it says that ...
Pieter Wuille's user avatar
4 votes
Accepted

What is the compact_size function used in BIP341?

It refers to the CompactSize encoding frequently used in the Bitcoin P2P protocol for integers (in particular, lengths of vectors). It's also called VarInt in some other protocol descriptions. Since ...
Pieter Wuille's user avatar
4 votes
Accepted

Is a BIP required for the removal of SegWit Discount for Inscriptions?

The removal of the witness discount would be a consensus change, specifically a soft fork. Changes to consensus rules have always been standardized as BIPs ever since the BIP process was created and I ...
Vojtěch Strnad's user avatar
3 votes

What is the current Status of major proposed BTC upgrades like Taproot, MAST, Submarine Swaps?

1) MAST: Essentially folded into Taproot 2) Taproot: Planned to be part of the upcoming SegWit V1 softfork. A formal proposal for that has been about two weeks away for half a year, so could appear ...
Murch's user avatar
  • 74.5k
3 votes
Accepted

Why does the median-past time average the last 11 block timestamps and not the last 12?

It is a median, not an average, thus it selects the 6th block's timestamp after sorting. If you're a non-native English speaker, international maths heuristics can be quite tricky. Double-check on ...
Paul Razvan Berg's user avatar
3 votes
Accepted

Why are some BIP numbers missing from BIPs list?

If I understood correctly https://github.com/bitcoin/bips contains a list of change proposals that have been accepted as BIPs by the BIP editor? Correct. Why are some of the numbers missing, ...
Pieter Wuille's user avatar

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