What does the Sender of a Transaction include in the Input that allows the Recipient to Unlock/Redeem?
I have been struggling to grasp what exactly is included in the input of a Transaction that allows the intended recipient to then redeem/unlock that UTXO when they are ready to do so.
I understand that a transaction contains a Digital Signature created by the Senders Private Key on the message.
I become confused when trying to understand what data the sender includes in the Transaction that allows the recipient to unlock that UTXO and turn it into a subsequent input when they choose to do so. Is the Sender including the Recipients Public Key in the Transaction allowing them to use a scriptSig to unlock that UTXO?
Thanks for taking the time out help
transactions
add a comment |
I have been struggling to grasp what exactly is included in the input of a Transaction that allows the intended recipient to then redeem/unlock that UTXO when they are ready to do so.
I understand that a transaction contains a Digital Signature created by the Senders Private Key on the message.
I become confused when trying to understand what data the sender includes in the Transaction that allows the recipient to unlock that UTXO and turn it into a subsequent input when they choose to do so. Is the Sender including the Recipients Public Key in the Transaction allowing them to use a scriptSig to unlock that UTXO?
Thanks for taking the time out help
transactions
add a comment |
I have been struggling to grasp what exactly is included in the input of a Transaction that allows the intended recipient to then redeem/unlock that UTXO when they are ready to do so.
I understand that a transaction contains a Digital Signature created by the Senders Private Key on the message.
I become confused when trying to understand what data the sender includes in the Transaction that allows the recipient to unlock that UTXO and turn it into a subsequent input when they choose to do so. Is the Sender including the Recipients Public Key in the Transaction allowing them to use a scriptSig to unlock that UTXO?
Thanks for taking the time out help
transactions
I have been struggling to grasp what exactly is included in the input of a Transaction that allows the intended recipient to then redeem/unlock that UTXO when they are ready to do so.
I understand that a transaction contains a Digital Signature created by the Senders Private Key on the message.
I become confused when trying to understand what data the sender includes in the Transaction that allows the recipient to unlock that UTXO and turn it into a subsequent input when they choose to do so. Is the Sender including the Recipients Public Key in the Transaction allowing them to use a scriptSig to unlock that UTXO?
Thanks for taking the time out help
transactions
transactions
asked Jan 24 at 22:19
Nathaniel RichardsonNathaniel Richardson
161
161
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
The transaction output has a property called the scriptPubkey
that is executed with the scriptSig
when the output is spent in a transaction. An understanding of Bitcoin script would help.
Bitcoin Script
Bitcoin uses it's own stack-based scripting language with a set of op-codes. This scripting language is used to determine whether an unspent transaction output (utxo) can be spent. When you send Bitcoin, you are really just assigning a Bitcoin value to a script, which can be spent only if the script executes successfully and results in a single true value on the stack. The script that is assigned to the Bitcoin transaction output is called the scriptPubKey
. To satisfy the script, you must provide the correct scriptSig
, which is also a script, which is prepended to the scriptSig
and executed to test if the spending succeeded. Let's look at an example:
scriptPubKey (raw): 76a914306e2ea1eed91bf66dfe5d94f3957d4ba63bde8488ac
scriptPubKey (assembly): OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG
In plain english, this script, when executed will do the following:
OP_DUP
: Duplicate the top item on the stack (place a copy of it on the stack)
OP_HASH160
: Pop the top item off the stack, calculate it's HASH160, i.e. theRIPEMD160(SHA256())
, and place that on the stack
OP_EQUALVERIFY
: Pop the top 2 items off the stack, and if they are not equal, it will exit immediately and fail, otherwise nothing
OP_CHECKSIG
: Pop the top 2 items off the stack, and use the top as the public key, the second as the signature, and verify the transaction signature
In order to spend this output, we must provide a valid signature and public key. We'll just provide 00
for the signature for this example, and not worry about the final checksig op.
Example
Let's visualize this example with a scriptSig
. Let's use kallewoof's btcdeb
Script visualization tool. After the first command, you can type step
once, and then just press enter each time after that to step through each operation:
$ btcdeb '[00 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG]'
btcdeb -- type `btcdeb -h` for start up options
valid script
7 op script loaded. type `help` for usage information
script | stack
-------------------------------------------------------------------+--------
0 |
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 |
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0000 0
btcdeb> step
<> PUSH stack
script | stack
-------------------------------------------------------------------+--------
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 | 0x
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0001 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_DUP | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_HASH160 | 0x
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0002 OP_DUP
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_HASH160 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_EQUALVERIFY | 0x
OP_CHECKSIG |
#0003 OP_HASH160
btcdeb>
<> POP stack
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_EQUALVERIFY | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_CHECKSIG | 0x
#0004 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
btcdeb>
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_EQUALVERIFY | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_CHECKSIG | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
| 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0005 OP_EQUALVERIFY
btcdeb>
<> POP stack
<> POP stack
<> PUSH stack 01
<> POP stack
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_CHECKSIG | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0006 OP_CHECKSIG
You can play around with this using any of the opcodes listed at Script.
add a comment |
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "308"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fbitcoin.stackexchange.com%2fquestions%2f83980%2fwhat-does-the-sender-of-a-transaction-include-in-the-input-that-allows-the-recip%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
The transaction output has a property called the scriptPubkey
that is executed with the scriptSig
when the output is spent in a transaction. An understanding of Bitcoin script would help.
Bitcoin Script
Bitcoin uses it's own stack-based scripting language with a set of op-codes. This scripting language is used to determine whether an unspent transaction output (utxo) can be spent. When you send Bitcoin, you are really just assigning a Bitcoin value to a script, which can be spent only if the script executes successfully and results in a single true value on the stack. The script that is assigned to the Bitcoin transaction output is called the scriptPubKey
. To satisfy the script, you must provide the correct scriptSig
, which is also a script, which is prepended to the scriptSig
and executed to test if the spending succeeded. Let's look at an example:
scriptPubKey (raw): 76a914306e2ea1eed91bf66dfe5d94f3957d4ba63bde8488ac
scriptPubKey (assembly): OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG
In plain english, this script, when executed will do the following:
OP_DUP
: Duplicate the top item on the stack (place a copy of it on the stack)
OP_HASH160
: Pop the top item off the stack, calculate it's HASH160, i.e. theRIPEMD160(SHA256())
, and place that on the stack
OP_EQUALVERIFY
: Pop the top 2 items off the stack, and if they are not equal, it will exit immediately and fail, otherwise nothing
OP_CHECKSIG
: Pop the top 2 items off the stack, and use the top as the public key, the second as the signature, and verify the transaction signature
In order to spend this output, we must provide a valid signature and public key. We'll just provide 00
for the signature for this example, and not worry about the final checksig op.
Example
Let's visualize this example with a scriptSig
. Let's use kallewoof's btcdeb
Script visualization tool. After the first command, you can type step
once, and then just press enter each time after that to step through each operation:
$ btcdeb '[00 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG]'
btcdeb -- type `btcdeb -h` for start up options
valid script
7 op script loaded. type `help` for usage information
script | stack
-------------------------------------------------------------------+--------
0 |
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 |
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0000 0
btcdeb> step
<> PUSH stack
script | stack
-------------------------------------------------------------------+--------
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 | 0x
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0001 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_DUP | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_HASH160 | 0x
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0002 OP_DUP
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_HASH160 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_EQUALVERIFY | 0x
OP_CHECKSIG |
#0003 OP_HASH160
btcdeb>
<> POP stack
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_EQUALVERIFY | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_CHECKSIG | 0x
#0004 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
btcdeb>
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_EQUALVERIFY | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_CHECKSIG | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
| 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0005 OP_EQUALVERIFY
btcdeb>
<> POP stack
<> POP stack
<> PUSH stack 01
<> POP stack
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_CHECKSIG | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0006 OP_CHECKSIG
You can play around with this using any of the opcodes listed at Script.
add a comment |
The transaction output has a property called the scriptPubkey
that is executed with the scriptSig
when the output is spent in a transaction. An understanding of Bitcoin script would help.
Bitcoin Script
Bitcoin uses it's own stack-based scripting language with a set of op-codes. This scripting language is used to determine whether an unspent transaction output (utxo) can be spent. When you send Bitcoin, you are really just assigning a Bitcoin value to a script, which can be spent only if the script executes successfully and results in a single true value on the stack. The script that is assigned to the Bitcoin transaction output is called the scriptPubKey
. To satisfy the script, you must provide the correct scriptSig
, which is also a script, which is prepended to the scriptSig
and executed to test if the spending succeeded. Let's look at an example:
scriptPubKey (raw): 76a914306e2ea1eed91bf66dfe5d94f3957d4ba63bde8488ac
scriptPubKey (assembly): OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG
In plain english, this script, when executed will do the following:
OP_DUP
: Duplicate the top item on the stack (place a copy of it on the stack)
OP_HASH160
: Pop the top item off the stack, calculate it's HASH160, i.e. theRIPEMD160(SHA256())
, and place that on the stack
OP_EQUALVERIFY
: Pop the top 2 items off the stack, and if they are not equal, it will exit immediately and fail, otherwise nothing
OP_CHECKSIG
: Pop the top 2 items off the stack, and use the top as the public key, the second as the signature, and verify the transaction signature
In order to spend this output, we must provide a valid signature and public key. We'll just provide 00
for the signature for this example, and not worry about the final checksig op.
Example
Let's visualize this example with a scriptSig
. Let's use kallewoof's btcdeb
Script visualization tool. After the first command, you can type step
once, and then just press enter each time after that to step through each operation:
$ btcdeb '[00 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG]'
btcdeb -- type `btcdeb -h` for start up options
valid script
7 op script loaded. type `help` for usage information
script | stack
-------------------------------------------------------------------+--------
0 |
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 |
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0000 0
btcdeb> step
<> PUSH stack
script | stack
-------------------------------------------------------------------+--------
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 | 0x
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0001 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_DUP | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_HASH160 | 0x
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0002 OP_DUP
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_HASH160 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_EQUALVERIFY | 0x
OP_CHECKSIG |
#0003 OP_HASH160
btcdeb>
<> POP stack
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_EQUALVERIFY | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_CHECKSIG | 0x
#0004 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
btcdeb>
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_EQUALVERIFY | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_CHECKSIG | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
| 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0005 OP_EQUALVERIFY
btcdeb>
<> POP stack
<> POP stack
<> PUSH stack 01
<> POP stack
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_CHECKSIG | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0006 OP_CHECKSIG
You can play around with this using any of the opcodes listed at Script.
add a comment |
The transaction output has a property called the scriptPubkey
that is executed with the scriptSig
when the output is spent in a transaction. An understanding of Bitcoin script would help.
Bitcoin Script
Bitcoin uses it's own stack-based scripting language with a set of op-codes. This scripting language is used to determine whether an unspent transaction output (utxo) can be spent. When you send Bitcoin, you are really just assigning a Bitcoin value to a script, which can be spent only if the script executes successfully and results in a single true value on the stack. The script that is assigned to the Bitcoin transaction output is called the scriptPubKey
. To satisfy the script, you must provide the correct scriptSig
, which is also a script, which is prepended to the scriptSig
and executed to test if the spending succeeded. Let's look at an example:
scriptPubKey (raw): 76a914306e2ea1eed91bf66dfe5d94f3957d4ba63bde8488ac
scriptPubKey (assembly): OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG
In plain english, this script, when executed will do the following:
OP_DUP
: Duplicate the top item on the stack (place a copy of it on the stack)
OP_HASH160
: Pop the top item off the stack, calculate it's HASH160, i.e. theRIPEMD160(SHA256())
, and place that on the stack
OP_EQUALVERIFY
: Pop the top 2 items off the stack, and if they are not equal, it will exit immediately and fail, otherwise nothing
OP_CHECKSIG
: Pop the top 2 items off the stack, and use the top as the public key, the second as the signature, and verify the transaction signature
In order to spend this output, we must provide a valid signature and public key. We'll just provide 00
for the signature for this example, and not worry about the final checksig op.
Example
Let's visualize this example with a scriptSig
. Let's use kallewoof's btcdeb
Script visualization tool. After the first command, you can type step
once, and then just press enter each time after that to step through each operation:
$ btcdeb '[00 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG]'
btcdeb -- type `btcdeb -h` for start up options
valid script
7 op script loaded. type `help` for usage information
script | stack
-------------------------------------------------------------------+--------
0 |
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 |
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0000 0
btcdeb> step
<> PUSH stack
script | stack
-------------------------------------------------------------------+--------
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 | 0x
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0001 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_DUP | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_HASH160 | 0x
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0002 OP_DUP
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_HASH160 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_EQUALVERIFY | 0x
OP_CHECKSIG |
#0003 OP_HASH160
btcdeb>
<> POP stack
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_EQUALVERIFY | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_CHECKSIG | 0x
#0004 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
btcdeb>
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_EQUALVERIFY | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_CHECKSIG | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
| 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0005 OP_EQUALVERIFY
btcdeb>
<> POP stack
<> POP stack
<> PUSH stack 01
<> POP stack
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_CHECKSIG | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0006 OP_CHECKSIG
You can play around with this using any of the opcodes listed at Script.
The transaction output has a property called the scriptPubkey
that is executed with the scriptSig
when the output is spent in a transaction. An understanding of Bitcoin script would help.
Bitcoin Script
Bitcoin uses it's own stack-based scripting language with a set of op-codes. This scripting language is used to determine whether an unspent transaction output (utxo) can be spent. When you send Bitcoin, you are really just assigning a Bitcoin value to a script, which can be spent only if the script executes successfully and results in a single true value on the stack. The script that is assigned to the Bitcoin transaction output is called the scriptPubKey
. To satisfy the script, you must provide the correct scriptSig
, which is also a script, which is prepended to the scriptSig
and executed to test if the spending succeeded. Let's look at an example:
scriptPubKey (raw): 76a914306e2ea1eed91bf66dfe5d94f3957d4ba63bde8488ac
scriptPubKey (assembly): OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG
In plain english, this script, when executed will do the following:
OP_DUP
: Duplicate the top item on the stack (place a copy of it on the stack)
OP_HASH160
: Pop the top item off the stack, calculate it's HASH160, i.e. theRIPEMD160(SHA256())
, and place that on the stack
OP_EQUALVERIFY
: Pop the top 2 items off the stack, and if they are not equal, it will exit immediately and fail, otherwise nothing
OP_CHECKSIG
: Pop the top 2 items off the stack, and use the top as the public key, the second as the signature, and verify the transaction signature
In order to spend this output, we must provide a valid signature and public key. We'll just provide 00
for the signature for this example, and not worry about the final checksig op.
Example
Let's visualize this example with a scriptSig
. Let's use kallewoof's btcdeb
Script visualization tool. After the first command, you can type step
once, and then just press enter each time after that to step through each operation:
$ btcdeb '[00 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 OP_DUP OP_HASH160 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 OP_EQUALVERIFY OP_CHECKSIG]'
btcdeb -- type `btcdeb -h` for start up options
valid script
7 op script loaded. type `help` for usage information
script | stack
-------------------------------------------------------------------+--------
0 |
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 |
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0000 0
btcdeb> step
<> PUSH stack
script | stack
-------------------------------------------------------------------+--------
030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046 | 0x
OP_DUP |
OP_HASH160 |
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0001 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_DUP | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_HASH160 | 0x
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 |
OP_EQUALVERIFY |
OP_CHECKSIG |
#0002 OP_DUP
btcdeb>
<> PUSH stack 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_HASH160 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_EQUALVERIFY | 0x
OP_CHECKSIG |
#0003 OP_HASH160
btcdeb>
<> POP stack
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
306e2ea1eed91bf66dfe5d94f3957d4ba63bde84 | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_EQUALVERIFY | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
OP_CHECKSIG | 0x
#0004 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
btcdeb>
<> PUSH stack 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_EQUALVERIFY | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
OP_CHECKSIG | 306e2ea1eed91bf66dfe5d94f3957d4ba63bde84
| 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0005 OP_EQUALVERIFY
btcdeb>
<> POP stack
<> POP stack
<> PUSH stack 01
<> POP stack
script | stack
-------------------------------------------------------------------+-------------------------------------------------------------------
OP_CHECKSIG | 030cfcefa07af9dd6dbe770b87d7dbdd2c31ba7f4fcf8f3a1196d502f13561b046
| 0x
#0006 OP_CHECKSIG
You can play around with this using any of the opcodes listed at Script.
answered Jan 24 at 22:28
JBaczukJBaczuk
4,7141321
4,7141321
add a comment |
add a comment |
Thanks for contributing an answer to Bitcoin Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fbitcoin.stackexchange.com%2fquestions%2f83980%2fwhat-does-the-sender-of-a-transaction-include-in-the-input-that-allows-the-recip%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown