sanket1729
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What does Bitcoin policy language offer the developer that Miniscript doesn't? What is the difference between Bitcoin policy language and Miniscript?
9 votes

At a high level: The policy is compiled to Minsicript. Miniscript is encoded to bitcoin Script. (One to One Mapping) Bitcoin Script is decoded back to Miniscript. (One to One Mapping) Policy and ...

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How to emulate SIGHASH_NOINPUT using CHECKSIGFROMSTACKVERIFY?
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6 votes

Eltoo relies on a primitive SIGHASH_ANYPREVOUT or SIGHASH_NOINPUT (hereafter referred as APO) BPI118, constructing Eltoo from APO would be replacing the CHECKSIG figure 4 of Eltoo paper with a ...

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How does SPV prevent double spending of UTXO?
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6 votes

In a bitcoin transaction, A's address is not scanned for spendable Unspent Transaction Outputs (UTXOs). Full nodes simply check if the inputs of the transaction are really unspent. There is no ...

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What is the purpose of submit header relative to submit block?
4 votes

The `submitheader RPC checks the header against the candidate chain tip to check if it is valid(i.e has sufficient PoW). Is that a legacy function? Or can it still be used? This can still be used ...

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How isn't blockchain fundamentally broken?
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4 votes

The chain works by verifying every previous block, right? How does this not become an exponential problem? I think you are assuming Blockchain growth is exponential with time, but it is linear with ...

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How is the human end of the Bitcoin network secured?
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4 votes

In an ideal world, we would want all programs to be auditable/verifiable(we can verify every execution path to be secure and correct). But that's far from reality, when you download a binary from a ...

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how pool mining works?
3 votes

Whenever a miner makes an attempt to solve the mining puzzle, the probability that this particular attempt will be successful is independent of how many other people are trying and even independent of ...

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Why is the block reward slightly higher than what it should be?
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3 votes

The coinbase transaction(the transaction that pays miner bitcoins) gets bitcoins from two sources. Block reward: This part goes on declining like 50/25/12.5 and so-on in a pre-defined schedule ...

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How does BIP9 handle expiration dates over retargeting periods?
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3 votes

As per BIP 9, the transition to FAILED takes precendence. Which means that the feature will not be activated via BIP09. The relevant part of the code. case STARTED: if (GetMedianTimePast(...

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How did they generate these vanity addresses with 27 predetermined characters?
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2 votes

Your observation is correct and indeed those addresses cannot be generated by vanity address generator in a reasonable amount of time. Most likely, there is no secret key corresponding to that address ...

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Adjustable block size
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2 votes

So, would it make sense to increase block sizes at least for these intervals and decrease afterwards? The key problem here is miners can introduce transactions in a block for free. In other words, ...

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What's the default strategy miners employ when they select txs from their pool?
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2 votes

You are correct, it is infact equivalent to knapsack problem. To the best of my knowledge most miners simply sort by fee and this gives a good approximation for optimal solution. A couple of things of ...

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Mining 0 fee transactions
2 votes

I think you are assuming that miners who are picking low fees transactions are not competing with anyone which is incorrect. Mining is not progressive(i.e your chances do not increase the more you try)...

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Mining Process - Transactions Selection
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2 votes

Most miners today simply use sort transactions by fee/byte and include them in blocks. This is optimal strategy for revenue maximization(ignoring the knapsack errors). When the nonce space is ...

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Does bitcoin have transaction fees?
2 votes

Yes, Bitcoin transactions have transaction fee. It is not proportional to amount of Bitcoins sent, but it is proportional to the size of transaction and it is measured in satoshi/byte. (10^8 Satoshi ...

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What is the probability of mining a block by a miner controlling a fraction of hashing power?
1 votes

In an ideal world, if a miner has α fraction of hashing power, the probability of them finding the next block is α. It should not depend on any other factor, but in real-world network speeds, block ...

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Script: How to check if the top item on the main stack is numeric or not?
1 votes

The best way that I know is quite involved because bitcoin-core standardness rules around Minimal representation of script ints. If you really need to do this, I can add detail in an updated answer. ...

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Proof of private keys ownership for multiple addresses
1 votes

I think what you need is a threshold signature(n of n). I don't know of any tools that would help you create such signature, but conceptually speaking it is not that difficult. You take all of the ...

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Is it possible to do a 3-of-5 OR 1 multi-sig for backup purposes?
1 votes

You can try to miniscript compiler http://bitcoin.sipa.be/miniscript/ with the policy or(pk(K1),thresh(3,pk(K2),pk(K3),pk(K4),pk(K5),pk(K6))) to get a corresponding Script. However, to the best of my ...

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Who can predict that a benign attacker has 51% hash rate of the system?
1 votes

1) As this benign attacker accepts any new block by other miners, is it again illegal to have more than 50% of the total hash-rate? It is not illegal to have any percent of hash rate, you are allowed ...

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What would be the benefits of 10x the energy spent
1 votes

Apart from Nate Eldredge direct consequence of increase in cost for 51% attacks, I would like to point out some indirect consequences. 10x mining power can be supported only by 10x rise in Bitcoin ...

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Did the Bitcoin fork resulting in the Bitcoin Cash created money from nothing?
1 votes

Yes, it is created out of thin air. Even I can create a fork of bitcoin anytime and announce it into the market. The huge difference is probably it won't be valued as much as BCH. Isn't this a ...

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Application of proof of work in bitcoin
1 votes

which problem does it try to solve? Imagine a P2P system in which all nodes are connected. Now, any peer can propose a block(these set of transactions) and say that it is valid and should be added to ...

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can sender send 2 amounts to single recipient in single transaction?
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1 votes

Yes. This sort of transaction is doable in bitcoin. A point which I would like ot highlight is that transaction fees in bitcoin are proportional to the transaction size in bytes(and not the amount ...

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Why are transactions not used for signalling?
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1 votes

Such a system could be easily gamed by people who simply spam the network with transactions and by miners who choose what transactions to include in their blocks. The penalty which they incur is still ...

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How to measure profit and losses in bitcoin investment?
1 votes

I am no expert in finances, but I look at profit calculation of investment in fungible goods in the way shown below: Total Profit(between time t1 and time t2) = Total assets at t2 - Total assets at ...

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Bitcoin Transaction Speed
1 votes

Payment channels are a way to prevent double spending in such cases. As per the Wiki A Micropayment Channel or Payment Channel is class of techniques designed to allow users to make multiple ...

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How do bonds in Secure Multi‐Party Lotteries work as described in Bitcoin and Cryptocurrency Technologies book
0 votes

The transactions for revealing commitments are separate from the transactions for the lottery. Timed hash commitments only force parties to reveal preimage x of H(x). The lottery logic is carried in a ...

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