# Questions tagged [ecdsa]

The Elliptic Curve Digital Signature Algorithm

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### How is a Bitcoin transaction signed using ECDSA?

I am quite familiar with the way secp256k1 ECDSA works as well as the equations that are utilised. However, I have no idea how this ECDSA applies to signing Bitcoin (SegWit Format) and transferring it ...
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### Why can't I reverse secp256k1's public key point in order to determine the private key?

I understand that the public key q is generated by the point addition of g (some secp256 k1 constant) u times such that u is a big number (private key). This process can be simplified in this diagram ...
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### How does ECDSA work when generating the public key?

I know the curve has formula y^{2}=x^{3}+ax+b. However, some websites are saying that a=0 and b=7 for secp256k1? What is secp256k1? Is it the curve that is always used or does it generate the field in ...
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### Can the difference be determined between two nonces k1, k2, having a linear relationship if the nonce and private key are unknown, i.e., k2 - k1 = n?

My question is related to weak signature vulnerability testing where a hypothetical attacker does not know the values of the nonce or private key itself, but can determine that the nonce 'k1' is ...
1 vote
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### Verifying the Pizza transaction in Python

A friend of mine and I are trying to learn how to read the bitcoin blockchain. We've gotten pretty much everything except the ECDSA verification that the coins spent actually belong to the person who ...
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1 vote
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### Is it feasible to calculate EC private key k from public key K for very low values of k?

If an EC private key k is very small, say "1", is it feasible to calculate the private key k from its public key K, since there would only be one step back to generator point G and therefore ...
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### How to calculate the public key, compute point P and create signature using ECDSA?

I'm quite new to the intricacies of bitcoin cryptography and ECDSA and elliptic curve cryptography has me quite stymied. I am faced with a curve with the equation: y^2 = x^3 + 7 of order N=39 with ...
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1 vote
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### Elliptic Curve and SECP256K1

Just for curiosity, considering that there is a server communicating with other machine (local machine let's call it). If we have the two public keys from Local and Server and we know that Private and ...
77 views

### How can i achieve this signature?

I want to make a signature in bitcoin where the nonce and private are the same. For example, the private key is 0x1000 and the nonce for the R value is also 0x1000
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### What is the probability of an ECDSA signature being less than 71 bytes

Since DER requires R and s values being minimally encoded signed integers, they could be less than the expected 32 bytes. What is the probability that one or both of R and s are less than 32 bytes for ...
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### Why do private keys have a range limit?

I am reading about ECDSA, and I find that the private key must be in (0,n), with n = FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE BAAEDCE6 AF48A03B BFD25E8C D0364141. Is n the total number of points on the ...
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### What is the relationship between r in signature and the public key

I've been reading about ECDSA in here. Step 11 says that you only need the ‘x‘ value (20 bytes) for the signature, and that value will be called ‘R‘ Does that say that R is the x-coordinate of the ...
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### How long is SIGHASH?

I am reading these two posts 1 2, and following step by step. I almost understand, but I still have some questions. Before signing, input script should be removed and replaced by pre locking script. ...
1 vote
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### Trying to get the Public key from Private key via secp256k1 [closed]

I have the private key in hex format like this: 9E524DE478970A9621C0E52890805D5F28E3620892BA6BFA701B026C6EE10A52 , now I am running the below python function to get the public key via ecdsa: def ...
1 vote
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### How many times and where exactly is ECDSA used in Bitcoin?

I'm currently a little confused about where exactly ECDSA is used in the transaction process... some resources seem to say it's used once, whereas others seem to say it's used three times. Which is ...
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1 vote
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### Error while installing libwally

I am trying to install libwally on my debian machine. I followed the installation guide but running ./configure I got the warning === configuring in src/secp256k1 (/home/standup/libwally-core/src/...
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### How to get public key and bitcoin compressed address from the coordinates (x,y) generated by ECDSA?

I have my x (0xca668a8b5f71e8724aada4b5343c28702a481787855cc42228b8fff97fe94d6a) and y (0x19dd3a603a55b3d8c5f62cbe177b9b63693fb8c91d76845bafc843a7aa19ea55) coordinates generated by ecdsa with a ...
261 views

### How to forge a signature with fixed Z value

I want to forge a signature with a fixed z value, what is the formula to do that
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### Curious about the Math that makes Bitcoin/Blockchain work ! Any good resources to learn it?

A bit of a background about me ; Computer Engineer but during my studies i didn't dive too deep into the maths , especially the maths that makes the blockchain and cryptography work looking for advice ...
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### How to derive the Private key when the two the nonces are k and k*2

Is the same private key using k and k*2 respectively in two different signatures vulnerable? If yes How to calculate the key in this case Here is an example, Both signatures are valid and the nonce of ...
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### What is the best site/tool/way for finding the RSZ values of a bitcoin transaction? [duplicate]

The two most popular sites for doing this are down which are https://2coin.org/ and https://2xoin.com/getRSZfromRawTX/ with no indication they'll ever return to be usable. Can anyone here link any ...
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### public key to private key using HASH TABLE (Pollard's kangaroo for SECPK1)

I have done a little bit of research on HASH TABLE (Pollard's kangaroo for SECPK1) I was wondering if there is any way to extract the private key range using the public key or the public address..??
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### Why is signature S value is unnecessarily high not safe?

I get frequent warning when sending RawTX to PushTX message (Non-canonical signature: S value is unnecessarily high) Why is signature S with a large value dangerous (that is, when the first HEX ...
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### What is the relativity between ECDSA public keys, if any?

Wondering if there is any relative connection between public keys? I know that they are a function of G, but is there any other connection they share? Is it possible to calculate how many G are ...
1 vote
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### Why MakeNewKey in key.cpp isn't called when getnewaddress or generate

Hi I'm student studying bitcoin-core. I tested bitcoin regtest mode, and I want to know when CKey::MakeNewKey() is called. when I do this, bitcoin-cli -regtest createwallet "wallet1" ...
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### As a developer, what steps do I need to take to generate private-public keys?

When developing (I'm using Apple Swift), what steps are needed in order to independently create my own pair of private-public keys (with the ability to restore a private key from a mnemonic phrase)? ...
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### Are there risks to using the same private key for both ECDSA and Schnorr signatures?

I think I've seen a comment by Greg Maxwell about this but am having trouble finding it. I think there was some risk when signing the same message with the same key with both algorithms? In this ...
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I've been researching some crypto related concepts and came across "Nothing-Up-My-Sleeve Numbers" and from what I understand I can generated a Bitcoin address that basically comes with an ...
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### Y coordinate of PubKey on elliptic curve prefix

Public keys in the form of 04[x,y] can be compressed since the x axis is symmetrical. Hence we only need the x-coordinate with the 02/03 prefix which states if Y is odd or even. I don't understand the ...
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### Is ECDSA signing supported from within a Taproot tree or must all signing be Schnorr?

Let's say a server is set up to do ECDSA signing and you want to include the requirement to provide a ECDSA signature within your Taproot tree (script path). Is this supported?
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1 vote
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### 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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### What previously existing technologies made Bitcoin possible?

When watching a tutorial, they mentioned that Bitcoin is based off 4 or 5 technologies that existed for at least a decade before Bitcoin. Satoshi Nakamoto was the first person to combine them all into ...
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### How convert Bitcoin Privat Key Compression to public address?

This script gets the public address from the uncompressed private key. import ecdsa import hashlib import base58 private_key = input("privatekey: ") # ...
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### What is the math behind Bitcoin's elliptic curve?

I have seen many videos regarding the math behind the bitcoin elliptical curve but none of them show the public key generation. They are just defining few steps. I need the complete math behind the ...
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### secp256k1 lib compiling issue "invalid use of incomplete type secp256k1_context"

I make a small test code (test.cpp), try to show the problem I meet: to compile use g++ -o test test.cpp -lsecp256k1 #include <stdio.h> #include "secp256k1.h" static ...
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1 vote
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### secp256k1 recovery id and how does the code work

Here I have some questions regarding the recovery id (recid) defined in secp256k1 implementation. I had found few posts about how the recid is defined and what does it mean, also the source code (...
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1 vote
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### How is the random number R for transaction signatures created?

I wonder about the random number used in signatures that result in R values ? x coordinate R = G(k) How is it created? Does it have a specific chars length? Is there a specific random generator used, ...
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### Random Number In R Value , what is it actually, is it the same as Nonce in the blocks

I wonder about the random number in R value ... if i am right , the R value is First part of the script signature which is combined of two parts (r,s) r = Gk (elliptic curve scalar multiplication) Or ...
1 vote
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### Is it possible to know if the result of 2 point subtraction is before or after G

I am trying to see if there is a way to see if subtraction of 2 points on the elliptical curve resulted in a point before or after G?. Let me explain what I mean by it. Let's take a point GP. Using ...
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1 vote
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### What is the relationship between a Bitcoin Private Key / Public Key / Address?

What is the relationship between a Bitcoin Private Key / Public Key / Address? I see that a private key / public key pair is generated, but is there a possibility of generating a private key already ...
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### How Can i Extract a Z value of a specific Bitcoin Transaction that Belongs to a merkel tree/root transaction?

am trying to find a z value of a transaction that is signed in a merkle tree/root block , i coudn't find a raw tx id in hex of that specific transaction that signed with specific address while a raw ...
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1 vote
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### Is my ECDSA signature always unique?

In P2PKH the validation script is: <sig> <pubKey> OP_DUP OP_HASH160 <pubKeyHash> OP_EQUALVERIFY OP_CHECKSIG If I always use exactly the same private key and always sign exactly the ...
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### Does every transaction have the same signature?

I want to know whether the bitcoin network generates the same signature for each transaction, because people have only one signature?
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### How to get the raw signature data of a transaction?

With the use of segwit, signature data is no longer part of transaction body and thus can’t be retrieved from block explorers. So is there a Bitcoin rpc method in order to get it directly without ...
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### Is that proved that breaking ECDSA as hard as solving ECDLP?

Is that proved that breaking ECDSA (Elliptic Curve Digital Signature Algorithm) as hard as solving ECDLP(Elliptic Curve Discrete Logarithm Problem)?
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### ECDSA public key to private key hex

I have an ecdsa public key how to get the private key of this public key; 0222d2deda24c03b2cc2b458c35780c62b6b5603c088709f17607b7ecf1399e4d7 how to solve this on python I am using Pydroid 3 on my ...
1 vote
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### Bitcoin's cryptographic protocol allows for leakage of information about one's Private Key, making recalculation of the private key possible?

Is it true that the cryptography which is used in bitcoin allows for leakage of information which could be used to recalculate the private key - IF you are continuously reusing the same public address ...
357 views

### What does this variable R mean

What does this variable R mean if it is the same in transaction signatures, and can I find S Z from the transaction I want an explanation or someone helps me to find the variables type address: ...