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29 votes
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Is it possible to convert a taproot address into a native segwit address?

I am afraid the sent coins are irrevocably burned. The reason is that P2TR addresses encode a (tweaked) public key, while P2WSH addresses encode a script hash. If someone would take a P2TR address so ...
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18 votes
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What is the script assembly and execution in P2TR spend (spend from Taproot)

Before we start I realize your question is only about single-sig scenarios, and you want an answer focused on how validation works. I will address these things, but I think I need to elaborate a bit ...
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14 votes
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Why does Taproot require a new address format?

Background P2TR addresses will be encoded using Bech32, although likely an amended version. In anticipation of Taproot getting merged, some proponents tested the behavior of various wallets and ...
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13 votes
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Musig Signature Interactivity

MuSig is interactive because each signer needs to provide a signature nonce (effectively randomness) before signing. This is not specific to MuSig, but applies to any discrete logarithm-based ...
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13 votes
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What is this unusual transaction in the Bitcoin blockchain?

The first output of transaction b53e3bc5…5377f141 has the following scriptPubKey: OP_PUSHNUM_1 OP_PUSHBYTES_32 01010101…0101010101 The segwit softfork in 2017 defined versioning rules for all native ...
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11 votes
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Why is no security lost by using 32-byte public keys in Schnorr signatures instead of 33?

From the (very recently updated) bip-schnorr draft: Implicit Y coordinates are not a reduction in security when expressed as the number of elliptic curve operations an attacker is expected to ...
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10 votes
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How can I find samples for P2TR transactions on mainnet?

Taproot activated in block 709 632, but the first P2TR transactions were in block 709 635. A few P2TR transactions that may be useful for test vectors would be: 33e7…9036, the first P2TR transaction ...
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9 votes
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Should the Bitcoin Core wallet (or any wallet) prevent users from sending funds to a Taproot address pre activation?

TL;DR: Wallets SHOULD allow sending to all bech32m addresses at this point, but wallets MUST NOT request P2TR outputs before the Taproot spending rules are enforced on the network¹. The design of ...
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8 votes
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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 ...
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8 votes
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Who would benefit from Taproot deployment?

Taproot benefits everyone who uses it, but it has the most benefit to those who use complex scripts and multisigs. Since that group is a small portion of users of Bitcoin, that may be why some people ...
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8 votes

Should I be worried that bitcoincore.org now suddenly only provides an "unsigned" Bitcoin Core installer?

Beginning with Taproot? Hmm... Something about this feels scary to me. Your mistrust is misguided. So, they are no longer making "signed" installers? The releases are still signed with ...
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7 votes
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Would a Schnorr PubKey be a different length than a Taproot PubKey like P2WPKH and P2WSH?

A P2WPKH PubKey is shorter than a P2WSH PubKey. No, not quite. A P2WPKH address is shorter than a P2WSH address. The addresses are both based on a hash of the underlying witness program (i.e. the ...
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7 votes
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What are the sizes of single-sig and 2-of-3 multisig taproot inputs?

Taproot generally has two ways of spending. The default way is to spend the output using the key path: pay-to-taproot then behaves like a p2pk output except that it is using a schnorr signature and ...
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7 votes
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How do the fees for taproot transactions compare to P2WPKH?

Taproot inputs are smaller but outputs are larger. Specifically, P2WPKH (Native SegWit) inputs and outputs take 68 and 31 vbytes in a transaction, respectively, while P2TR (Taproot) inputs and outputs ...
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7 votes
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Is there a way to convert a P2PKH address into P2TR?

Short answer: no, at least not via the key path (and using a script path would be less efficient than using P2WPKH instead) Longer answer: no, and even if it were possible, this would be a terrible ...
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7 votes
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Can Schnorr aggregate signatures be nested inside other Schnorr aggregate signatures?

TL;DR: depending on what you mean, there is probably no published scheme with a security proof, but there is hope for such a scheme. First, a few clarifications Aggregation is just a concept, not an ...
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6 votes
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What are some interesting applications of Taproot "smart contracts"?

I think it's important to note first that BIP341-BIP342 are improvements to the Bitcoin script "framework" more than they are improvements to the smart contracting "functionality". ...
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6 votes

What are "leaf versions" in Taproot?

To add to Michael Folkson's answer, a question one may have is what the differences are between witness versions and leaf versions. Why do we need both? Leaf versions are not revealed until an output ...
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6 votes
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What are "leaf versions" in Taproot?

SegWit introduced versioned witness programs. When satisfying a script to spend coins you need to provide a redeem script consisting of a version byte and a witness program. The version introduced ...
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6 votes
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In theory could we skip the proposed Taproot soft fork, activate Simplicity instead and use Simplicity to write the equivalent of Taproot scripts?

I think that's both very premature, and misses the point. Simplicity is a completely different approach to scripting, with significant advantages, but it's being designed from the ground up. There is ...
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6 votes

What kind of privacy does Taproot give bitcoin?

Taproot allows inputs to hide the fact that there is a script specifying a contract. If sufficient parties involved in that contract agree and cooperatively spend the Bitcoin, that input looks just ...
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6 votes
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I would like to dig into the open Taproot PR to understand it, test it and possibly even review it. Any advice or recommendations?

Previous Bitcoin Core PR review club sessions A good starting point is the various Bitcoin Core PR review club sessions that have been held thus far on specific commits of the Taproot PR. The latest ...
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6 votes

Will "Taproot" replace Lightning Network?

With respect to the original wording of the question I believe Taproot will actually make the Lightning Network pointfull instead of pointless. While Taproot allows us to save some space on the ...
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6 votes

Will "Taproot" replace Lightning Network?

Will Taproot allow me to skip Lightning Network and simply use pure Bitcoin Core? Well, Bitcoin Core doesn't support Lightning for now, and probably won't for the foreseeable future, but there is no ...
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6 votes

Does the Taproot update benefit all bitcoin users? or is it for a selective amount of people

Bitcoin transactions require a certain size and with taproot and tapscript we can decrease that size. This means that effectively we will be able to store more transactions in one block allowing ...
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6 votes
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Will P2TR make P2WSH obsolete?

As far as I can tell, P2TR is better than P2WSH in almost every way. I cannot think of a case in which it would be a significant advantage to use P2WSH over P2TR, except that P2WSH is already ...
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6 votes
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Where can I get some MuSig2 test vectors?

As far as I know, there is not even a published specification for MuSig2. One is being worked on at https://github.com/ElementsProject/secp256k1-zkp/blob/master/doc/musig-spec.mediawiki, but it is ...
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5 votes
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Does v1 Segwit includes v0?

If this question is about the recently published bip-taproot proposal, the answer is no, you cannot use a v0 script inside a v1 output. The general reason for this is that some of the goals the BIP ...
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5 votes

What are Merklized Alternative Script Trees?

The idea of Merklized Alternative Script Trees (or previously Merklized Abstract Syntax Trees) dates back to an idea Russell O'Connor had in 2012. The original idea was that you could have alternative ...
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5 votes
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Can Taproot be used to commit arbitrary data to chain without any additional footprint?

Yes, you can commit to data this way, but there is nothing special about Taproot here. The Pay-to-Contract construction used to tweak the root key in Taproot is generally usable, and has in fact been ...
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