This tag should be used for questions regarding Bitcoin transaction scripts or scripting languages used in transactions of altcoins such as Solidity. Scripts are a set of instructions on how to complete a transaction.
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9 views
Why does the Lightning RFC require that HTLC ouputs go through succes and timeout transactions?
BOLT 3 describes HTLC output scripts:
(https://github.com/lightningnetwork/lightning-rfc/blob/master/03-transactions.md#offered-htlc-outputs)
The payment going to the owner of each commitment ...
1
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0answers
21 views
Segwit versioning limitations
Currently my understanding is that if new version of Segwit script is introduced, you are free to create whatever crazy rules you want there as long as they do not go against any valid consensus rules....
1
vote
1answer
96 views
what if a coin is spendable by multiple keys?
it seems like the scripting language could allow multiple private keys to spend a coin?
what if i send a coin to someone, but also allow it to be spendable by me. would their wallet still show they ...
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1answer
41 views
Bitcoin's script expressivity
I'm conscious that Bitcoin's script is not turing complete, as multiple answers point out (e.g., this answer and this one). But I'm wondering if script can express the language of a PDA or ...
4
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1answer
56 views
Trying to get a deeper understanding of atomic swaps
I'm an IT-student and writing a thesis about atomic swaps on BTC and BTC-like blockchains. For the thesis I decided to use BTC, LTC, BCH and DCR. These chains have a somehow similar codebase and the ...
1
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1answer
30 views
Why is the output address a list in RPC/console?
Vout contains a list of addresses, which I noticed to be always with size = 1, if it exists. The following is an example from Bitcoin Testnet:
{
"value": 0.91840581,
"n": 2,
"...
7
votes
1answer
82 views
What's the use of not relaying non-standard transactions if anyone can still use them using P2SH?
It seems that non-standard transactions are not normally relayed because there is a concern this might break the network or it might make future upgrades harder.
But anyone can use these non-standard ...
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0answers
24 views
Bitcoin transaction scripts : does ScriptSig or ScriptPubkey run first? [duplicate]
I'm confused as to the order regarding which script is run. For examples sake: say I want to spend 1 Bitcoin which was given to me by Alice in a single transaction of value 1 Bitcoin. I understand ...
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0answers
18 views
How can users verify bitcoin escrows, or any bitcoin smart contract?
Coming from an ethereum background, one can view a contract that you send ether to before you send it and verify that the logic works as advertised.
How can bitcoin users do the same? Or am I ...
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2answers
125 views
P2SH signature verification in python
I am trying to understand and verify P2SH script by writing a python code to parse real transaction in blockchain. I have chosen below Transaction randomly.
TxID: ...
5
votes
1answer
145 views
Bitcoin Script tutorial
Are there any tutorials with examples on Bitcoin Script: from basics to complex scripts?
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1answer
1k views
Is sha-1 used in Bitcoin?
The Bitcoin scripting language has OP_SHA1 as one of its opcodes. However, I'm not able to find any usage of this opcode (it is not used in any standard scripts nor in any other procedures such as ...
2
votes
1answer
51 views
Addresses field in ScriptPubkey
"txid": "055f9c6dc094cf21fa224e1eb4a54ee3cc44ae9daa8aa47f98df5c73c48997f9",
"hash": "055f9c6dc094cf21fa224e1eb4a54ee3cc44ae9daa8aa47f98df5c73c48997f9",
"version": 1,
"size": 433,
"vsize": 433,
"...
0
votes
1answer
25 views
Why do I get 5 bytes worth of 0x00 hex values in both outputs?
From the hex generated by the createrawtransaction command, I understand that the following is the output value:
...
0
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2answers
27 views
Breaking down the hex value for output 1
Within the hex generated by createrawtransaction, I am trying to understand the output 1 hex.
The output 1 hex I have is:
76a914ab68025513c3dbd2f7b92a94e0581f5d50f654e788ac
Spacing out the ...
1
vote
0answers
56 views
Locktime requirement not satisfied when locktime set to 1 in p2sh
I've created the following script on testnet:
OP_IF
2 <pubkey1> <pubkey2> <pubkey3> 3
OP_CHECKMULTISIG
OP_ELSE
1 OP_CHECKSEQUENCEVERIFY
OP_DROP
<pubkey1&...
2
votes
1answer
55 views
Lightning close-channel transaction example?
From this article, I can understand that a punishment-based bidirectional payment channel (the type used by Lightning) would contain roughly this bitcoin script as one of the outputs:
OP_IF
“+7 days” ...
0
votes
1answer
33 views
Possible to check who signed the transaction in a multi-sig transaction case?
Say you have a multi-sig tx that originated from a 2-of-3 P2SH address.
Is it possible to say who signed the transaction? i.e. you can get access to the redeem script once the tx is broadcasted, and ...
0
votes
1answer
55 views
Parse scripts to extract address [duplicate]
I want to parse a script with c++ to gain an output address from it.
can anybody introduce a suitable library or a sample code which extract addresses from scripts ?
0
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1answer
40 views
Extract output address from raw script in bitcoin protocol
I'm working on bitcoin protocol and exactly i want to extract raw script from output script to gain address from tx messages.
for common scripts, like scripts start with 0x76(means OP_DUP), we can ...
1
vote
1answer
41 views
unknown output script in a sample bitcoin pcap file
I start working on bitcoin protocol to extract output addresses from scripts in tx structures. Now in can produce some valid bitcoin address but some scripts are not familiar in op_code lists ...
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0answers
18 views
Script Mistake in Asymmetric Revocable Commitments [duplicate]
Disclaimer
Please note that this is not a question on lightning network or on hash time lock contracts since those subjects come later in the book, so answers that relate to those subjects are not ...
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1answer
65 views
Bitcoin RIPEMD160 purpose
Bitcoin uses RIPEMD160 on top of SHA256. Is its sole purpose to make public key address shorter or does it strengthen security in any way?
5
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2answers
93 views
Getting Started With Script
I would like to manually write a few locking and unlocking scripts to get a deeper feel for that part of the network. What is the simplest step-by-step set of instructions to set up everything needed ...
2
votes
1answer
62 views
Extract lightning network funding transactions with python bitcoin blockchain parser lib
My ultimate goal is to parse funding transactions (as well as channel closes in a later step) from the blockchain. In order to do so I wanted to start with a funding transaction and disect it. ...
0
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1answer
86 views
Electrum Gap Limit from CLI
Is there any way to change wallet gap limit in Electrum from command line? If yes, how? If not, could it be bypassed using some kind of external script? I really need to avoid GUI. Thank you in ...
1
vote
2answers
212 views
What redeem script is used in bitcoin core wallet when generate the address?
I'm trying to generate the address 38DGj87axzmQiZeAd1w1y5FEmuu5a7pfBa in my bitcoin core wallet with code.
First, I dump the private key from the address, then I calculate the address from the ...
3
votes
1answer
52 views
Weird script stack entries at block #227837?
At block 227837 , the coinbase TX
e35ca7413b61397a49551fea6ebb540988afcf4a2d0e750773d38eb11b138f40
has the following script:
...
1
vote
1answer
106 views
How does a P2SH script get executed?
I'm trying to visualize how a typical P2SH script gets executed, as I realize that it's a special form of script that gets executed slightly differently to a standard script.
Before P2SH:
Before ...
0
votes
1answer
39 views
Does bitcoin still concatenate the locking and unlocking script and execute?
Does bitcoin still concatenate the locking and unlocking scripts and execute in order to validate transaction or is validation done another way?
0
votes
1answer
26 views
How can OP_CHECKLOCKTIMEVERIFY be used to create outputs provably spendable by anyone?
While reading BIP 65 it says that op_checklocktimeverify can be used to create provably spendable outputs by anyone. How is this possible?
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0answers
24 views
How to create contracts using bitcoin?
Is there a way to create contracts with bitcoin such as allowing a transaction being funded by segwit outputs to be broadcasted only if the receiver signs it or only if the scriptsig contains a ...
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1answer
71 views
What does a coinbase output script look like?
What does a coinbase output script look like and how would it be used to fund a transaction?
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2answers
35 views
how to use multiple time specific address in input scripts with difference balances?
look at to the following transaction (withdraw transaction from binance)
https://blockchain.info/tx/404fd22d3d88d129975d03fe2993f0126db8f066b3d8126d6cca676747439515?show_adv=true
How in input scripts ...
1
vote
1answer
27 views
Bitcoin multisig contract - to Lock coins with nTimeLock (BIP65)
I really need help.
I am currently Developing a Bitcoin wallet and want to build in a SMS Based send function where the sender does not need to know the receiver publicKey. After the contract get ...
2
votes
1answer
112 views
How do I fix my check-multisig if-else output script?
I'm trying to create a custom script with if/else and a multisig operation in one branch. Currently, my script looks thus:
OP_IF
<pub1>
OP_CHECKSIG
OP_ELSE
OP_2
<pub2>
...
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0answers
20 views
Valid p2sh transaction using only the redeem script
Is it possible to create a valid p2sh transaction using only the redeem script in the scriptsig and no signature?
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1answer
137 views
How to find out the requirements for spending an output script?
How do you find out the requirements to spend an output script?
Do you decode the hash?
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0answers
27 views
How to create output scripts? [duplicate]
How are output scripts created and how can you create your own scripts or is this only possible through creating a transaction?
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0answers
34 views
P2sh transaction with non standard script
How can you relay a p2sh transaction with a non standard script, such as a scriptsig that only contains OP_True and get it mined?
Example:
https://blockchain.info/tx/...
0
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1answer
174 views
P2sh redeem script hash
What are the contents of a redeem script hash in a p2sh transaction?
From what i read it's similar to the pubkey script but does it only contain the receiver's address?
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0answers
85 views
Is it possible to create a Dapp on top of Bitcoin?
Is it possible to create a dapp on top of bitcoin similar to how it can be done with ethereum? Can it be just as capable as ethereum?
1
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1answer
59 views
Ho to identify a multisig transaction?
79fbae117dc38effafb33304af83ce4894589747aee1ef992f63280567f52f5ba870678b4ab4ff6c8ea600bd217870a8b4f1f09f3a8e8353aeffffffff0130d90000000000001976a914569076ba39fc4ff6a2291d9ea9196d8c08f9c7ab88ac00000000
...
1
vote
1answer
88 views
Why don't P2PK scripts have their own address?
If I understand addresses correctly, different types of addresses are used to map to a particular locking script (scriptPubKey).
So based on the leading character of an address, a wallet will decode ...
1
vote
1answer
37 views
How to calculate variable length fields?
Some parts of bitcoin tx Ex: Script are of variable length var_int. Can someone explain how to calculate its value from that var_int table.
Ex: In the below tx, the bolded part is script-length. its ...
2
votes
2answers
130 views
Does the alternative stack make Script Turing complete?
The wiki documents the presence of an "alt stack" in Script:
OP_TOALTSTACK Puts the input onto the top of the alt stack. Removes it from the main stack.
OP_FROMALTSTACK Puts the input onto the top of ...
0
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2answers
72 views
How is a transaction formated/signed?
Every transaction takes unspent outputs as inputs and creates new outputs. The creator of the transaction uses his private key to sign the transaction and nodes validate that transaction by using the ...
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2answers
54 views
Why is this script invalid, and how can I generate valid public key/digital signature pairs?
Why does the default P2PKH transaction at http://bitcoin-script-debugger.visvirial.com/ return NULL rather than true? I haven't tried to swallow the gory details of OP_CHECKSIG yet, but everything ...
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0answers
42 views
What does this elaborate output script mean? [duplicate]
Bitcoin transaction a214a2daf91691afdd491fd00d894eb3301e35bc18b5554b14e12843037e954c has an interesting output script:
PUSHDATA(33)[...
1
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1answer
35 views
Can I use opcodes traditionally used for verifying keys to verify payment sizes?
Can I use binary opcodes usually used for verifying keys to verify payment sizes?
It looks like these opcodes like OP_EQUALVERIFY and OP_NUMEQUALVERIFY are used for checking signatures or keys, ...
