Questions tagged [signature]

This tag should be used for questions regarding digital signatures. A digital signature proves that the owner of a private key produced or endorsed a given message. These are used in transactions to prove that an output can be spent in a transaction.

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1answer
543 views

Bitcoin ECDSA signature in the compact format

I would like to understand how to get Bitcoin ECDSA signature in a compact format, when it's exactly 65 bytes. In the bitcoin-core repository, secp256k1_ecdsa_recoverable_signature_load is ...
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1answer
2k views

Signature verification in python using compressed public key

I am trying to learn bitcoin blockchain programming. I am trying to verify signature in Transaction with txid: 4269fdc239d027922dcec96f1ae283dbaff10e2d1bd49605661d091e79714956 I am getting ...
2
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1answer
689 views

Verifying a legitimate version of bitaddress.org on Windows

How can I make sure I am accessing (online) or have downloaded (as an HTML file or from GitHub) a legitimate, trustworthy version of bitaddress.org? In other words, how can I make sure no hacker has ...
2
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1answer
546 views

Signing tx with OpenSSL, but fails when sending with bitcoin qt. How to debug?

I try to create a tx with 4 inputs, and sign it via cmdline and openssl on a cold storage machine. Then I want to send it via bitcoin qt (or blockchain.info). Signing with a single input and a single ...
2
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1answer
809 views

Calculating Z value in a tx with 1 input and 2 outputs

After reading this: ECDSA Signature and the "z" value I'm still confused about the 'Z' value, for this transaction: https://blockchain.info/tx/...
2
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1answer
1k views

Can't find correct z1 & z2 for transaction

I've been trying to understand the issue and repeat Willem Hengeveld's answer, but I think I'm failing at getting correct script for hash. I'm looking for this transaction, my scripts are: ...
2
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1answer
157 views

What is the algorithm used to sign data within Nxt?

I understand that Nxt uses Curve25519 to generate pubkeys for user accounts, however, I can't find a reference that states what which signing algorithm/process is used for transactions and blocks. (...
2
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2answers
113 views

Are Bitcoin signatures currency specific?

I am wondering whether signatures for Bitcoin-like currencies are currency specific, or given one program that can sign a Bitcoin raw/JSON transaction one can create valid signatures for other coins ...
2
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1answer
928 views

signrawtransaction - Which private key from BitAddress.org?

I am trying to do multisignature addresses and when it comes time to spend the funds, I am getting stuck. If I create a 2 of 3 multisignature address using 3 public keys that I generate locally, then ...
2
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1answer
163 views

Would a transition to a different signature scheme be feasible?

The recent problem with Android's SecureRandom PRNG once again shows that using (EC)DSA can go horribly wrong if the signature nonce is ever reused. There is an elliptic curve signature scheme that ...
2
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1answer
350 views

How can I use message signing to prove that I have private keys for many different accounts?

I want to prove the total sum of BTC I have access to. Therefore I think if I use message signing to assert "owned by makerofthings7" in each address, then anyone can compute the total coins in my ...
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0answers
44 views

Why is adding s values in half aggregation insecure?

Jonas Nick an Tim Ruffing discussed in a presentation that summing up the s values in signature half aggregation would be insecure (without giving the reason) They presented a secure solution which ...
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0answers
32 views

Sign transaction externally

I create a transaction with inputs from a given address / public key without signatures. Every input needs to be signed. I use a different method to generate the signatures so I can't provide a ...
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0answers
174 views

Getting Error “Unable to sign input, invalid stack size (possibly missing key)”

I have created a key from using coinstring, and then imported it into my wallet. Then I ran: bitcoin-cli signrawtransactionwithkey "$rawtxhex" "[\"$mykey$\"]" But it results in: Unable to sign ...
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0answers
147 views

How to Validate Signature with SigScript length 8b?

I created a raw Transaction: ...
2
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0answers
33 views

Script and DER in P2PKH

Im trying to figure out the script and DER In P2PKH, the "first part (scriptsig)" push in stack (<sig><pubK>) because is it DER? Instead the "second part (scriptPubKey)" you can map the ...
2
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1answer
186 views

NBitcoin get signature, use spending P2SH transaction with non-standard script

After creating a new NBitcoin transaction (with a single pay-to-script hash input and multiple outputs), is there any way to calculate the transaction signature and manually put it in the inputs[0]....
2
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1answer
252 views

Why do we need public key as part of Witness in P2WPKH transactions?

As we want to minimize the data payload in a blockchain, which also led to concepts like SegWit, and is matter of discussion in Signature aggregation etc, I wonder why do we actually need to supply ...
2
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0answers
41 views

Proving sendership of transactions

Why does Bitcoin Core, on the message verification tab, say that verifying messages signed by Bitcoin addresses "only proves the signing party receives with the address, it cannot prove sendership of ...
2
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1answer
1k views

How do I get hash to verify transaction?

If I have the public key and signature for a transaction how do I get the hash value that is used in verify(hash, sig, pubkey). I want to know how to work backwards from a raw transaction to get it, ...
2
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1answer
525 views

Multi-Signature Transaction - Verify First Signature is Valid?

Using Gavin Anderson's TwoOfThree.sh Gist located here: https://gist.github.com/gavinandresen/3966071 Is it possible to verify the first "partial" signrawtransaction is valid from the known public ...
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2answers
170 views

Is it safe to share bitcoin address and signature generated from electrum wallet

Some bitcoin airdrops are asking to prove ownership on bitcoin address by sharing signature. My question is if one shares bitcoin address and signature is there any risk of a attacker to compute the ...
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2answers
184 views

Do you sign only the previous output of transaction?

I need to confirm that I understand how transactions work in the Bitcoin network. Ok, so: Alice is a network node. Alice wants to send bitcoins to someone in the network. Alice is creating a ...
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3answers
941 views

Sign a tx with “low s” value using OpenSSL

I currently try to sign a tx using OpenSSL. After some tinkering I think I got most of the tx right but Electrum complains with mandatory-script-verify-flag-failed (Non-canonical signature: S value is ...
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1answer
489 views

tiny-secp256k1 and ECDSA signing determinism

I noticed in bitcoin when using the tiny-secp256k1 library to sign the signature for a signature hash of an input, the signature is always the same. However in other ECDSA secp256k1 libraries (im ...
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1answer
209 views

Where is SIGHASH_TYPE serialized in SegWit?

When preparing or verifying a signature, a transaction pre-image is created in memory. This pre-image exists purely for the purpose of creating a signature and is not published to the blockchain. At ...
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4answers
2k views

Generate and push raw Bitcoin transaction

When I try to push a raw Bitcoin transaction via the blockchain.info API I get the following error message: Script resulted in a non-true stack: [] Transaction should send 0.001 Bitcoins with a 0....
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1answer
122 views

Sign transaction legacy with Openssl

I want to understand how Bitcoin sign transactions with Openssl. I saw this post But I have some issues. Above my private and public keys. Private keys: $ cat chiave_priv_3.pem -----BEGIN EC ...
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1answer
348 views

How to verify a signed message by bitcoin core?

I want to verify, in Java, a signature produced with bitcoin core's signmessagewithprivkey (equivalent to the verifymessage). I noticed a bitcoinj method similar to the bitcoin core's verifymessage - ...
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1answer
147 views

How can you calculate the inverse of S component of signature, while you cannot do it in ECC to calculate private key from public key?

When verifying the signature in bitcoin, we calculate S^(-1) * hash(m) * G + S^(-1) * R * pub_key and verify that this is equal to the temporary public key. Given the same logic, why can't we use it ...
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1answer
323 views

Why hash witness script instead of pubkey script in signature?

When a segwit input is signed, the signature will commit to the witness script (or a p2pkh-like script in case of p2wpkh). This is specified in BIP143: For P2WPKH witness program, the scriptCode ...
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1answer
34 views

which was the purpose of changing the signature of a TX? or it was just a bug before segwit?

Was there any purpose in changing the signature of a transaction? Or it was a bug before segregated witness? Does segregated witness disable some wanted feature?
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1answer
577 views

Why are the inputs of Bitcoin transactions signed?

This is my understanding of what a transaction looks like: inputs: input0: txid: <funding tx0 TXID> outputID: <output ID of UTXO in the funding tx0> scriptSig: <...
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1answer
58 views

Transaction Malleability, if i want to change signature, what part should I change, so that it would remain valid?

I know what transaction malleability is, but I don't understand how someone can change my signature so that it would remain valid. For example, If I want to change signature what part should I change, ...
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1answer
326 views

What happens if I use same k twice in DSA algorithm?

To sign a message , we choose nonce k but what happens if we use same k twice to sign a message using DSA algorithm?
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2answers
3k views

How to manually verify a signature given scriptSig and scriptPubKey?

First transaction Given a transaction on the blockchain: 3a1b9e330d32fef1ee42f8e86420d2be978bbe0dc5862f17da9027cf9e11f8c4 One of the outputs transfers 424,242.42424242 BTC to ...
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2answers
107 views

'01' at the end of signatures

I am confused about the end marker at the end of signatures (in my case, individual sigs for a Tx that spends a P2SH) in pybitcointools: pybitcointools: ...
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1answer
254 views

Can you include a signature in a bitcoin payment?

I know you can use the bitcoin client to sign messages (for which you own the private key) and verify messages from other public addresses. But can you actually embed a signed message into a ...
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1answer
2k views

Two identical R value finding z value from two transaction

tx1 from the trans1 i got Input Scripts 30450220262e481b6d8905b5adba67aff05eb8261501b0a9434c0b7f043d00cf8d23c91b022100bf82c0d212f30d3a0599e9b879516d762eaf5688ab83787cf470e99af5a6917101 ...
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1answer
2k views

How can I verify the the PGP signature of bitaddress.org?

bitaddress.org appears to have a versioning system and a PGP signature to confirm the source code hasn't been hacked. If I save the source code for the page (so I can run it on an offline computer), ...
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1answer
60 views

Why is full blockwide signature aggregation of schnorr signatures non-interactive?

I can only think of the MuSig paper describing how Rouge attacks are prevented by also committing to the public key of all signers. But as far as I understand the case of multisig is not the same as ...
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1answer
80 views

What does bitcoin do that prevents someone from using your coins by just generating a key pair and saying “you” sent those coins?

I think I'm missing and understanding about the current process of how your wallet works and how the transactions are signed. For example, if I'm user "A" and there exists a transaction from ...
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1answer
39 views

Are high-s ECDSA signatures forbidden in segwit witnesses?

I must have looked that up five times by now, but did segwit actually forbid high-s ECDSA signatures in witnesses, esp. in standard single-sig constructions such as P2SH-P2WPKH or P2WPKH? Or are high-...
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1answer
184 views

How to verify if a transaction is signed correctly?

Given an arbitrary signed raw transaction, how can we easily verify if all inputs are correctly signed (assuming all inputs are existent/unspent and the fee is higher than zero)? Bitcoin core's RPC ...
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1answer
344 views

How to sign a PSBT transaction?

I have a PSBT (in Base64 format) which I need to sign using GoLang, but I can't figure out which steps I need to do that. I found this but I'm not really confident with Bitcoin and Python, so I didn't ...
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1answer
100 views

What is “signature recovery”?

Bolt #11 defines a "tagged field," n, which identifies the payee by a public key, but it isn't required. It also requires a signature which can be verified only if the public key is known. When ...
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1answer
97 views

What goes in the tx hash preimage when signing with 0x83 (SINGLE|ANYONECANPAY)?

I have script to create a P2WPKH to P2WPKH transaction (1 input, 1 output) and sign it with the sighash type 0x01 SIGHASH_ALL. Which fields would I need to change in the tx digest preimage to turn ...
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2answers
81 views

What happens when the verification of a manipulated transaction fail?

If a malicious miner changes the amount in a given transaction, the hash value of the block changes. Thus, he has to find the required hash value again in that block. Let's say he successfully found ...
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1answer
134 views

P2PKH - Sharing a wallet address does not reveal my pub key?

Is it technically correct to say that if I share my address with the network, nobody has access to my pubkey still? But if I share a valid signature to a P2PKH UTXO, someone can derive my pubkey and ...
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1answer
144 views

For a transaction with a single input and output, is there a difference between SIGHASH_ALL and SIGHASH_SINGLE|SIGHASH_ANYONECANPAY

I have an signing implementation that already works for SIGHASH_ALL, and I'm trying to also support SIGHASH_SINGLE|SIGHASH_ANYONECANPAY. I'm referencing https://en.bitcoin.it/wiki/OP_CHECKSIG for the ...

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