Questions tagged [cryptography]
Concerning the broad subject of cryptography and its narrow application in Bitcoin protocol and applications.
298 questions
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How to implement coinscrash.com model of deposit & withdraw flow for my crypto poker casino?
In coinscrash.com for each user they generate separate bech32 address for deposit & displays the deposited amount as balance in top of the navigation bar.
Similarly for withdraw they just ask for ...
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Help recovering funds: Wallet created with non-standard public key format (no 02/03/04 prefix)
Title: Help recovering funds: Wallet created with non-standard public key format (no 02/03/04 prefix)
I have a Bitcoin address (19CLgD8MqfWzE3BzzUGjyXKM4EP72XgYJ8) containing ~0.064 BTC that was ...
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Is there any major flaw in this seed-phrase encryption approach?
I would like to add some security to my seed phrase storage for existing wallets. I'm not trying to make it absolutely secure, just want to make it much more difficult to access my fund if someone ...
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138
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What is exactly Randstorm vulnerability?
I've read the article from Unciphered about it, multiple times, and still fail to understand it
It basically says that wallets generated by BitcoinJs front end library from 2011 to 2015 are vulnerable ...
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48
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Can I recover my investment? I've been scammed [duplicate]
I am a victim of a scam. There is a company saying that they can recover what was stolen, it's almost 200 k euros and according to them, I am required to top up the balance of your secure crypto ...
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69
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Is it possible to reduce the field size without disrupting generation of public keys?
I have a curious question, i am aware of the curve parameters of secp256k1. i was wondering if its possible to reduce to field to a 130 bit or lower without disrupting the actual functionality.. what ...
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Bitcoin Core VM and hardware SHA256
It has come to my attention recently that linux machines store info about their cryptographic capabilities in /proc/crypto.
A baremetal machine I have shows sha256_ssse3 in the sha256 module parameter,...
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How to know the number of digits in the decimals place in division results (ECC SECP256K1)?
p - is the order of the finite field
n - is the order of the group. Private keys can range from 1 (the generator point G) to n - 1.
All the private keys (Priv) lie in certain ranges of 2.
2^a < ...
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507
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Why does BIP-340 use secp256k1?
If the entire Taproot/Schnorr soft-fork was going to implement an entirely new signing scheme anyway that was completely independent from the previous ECDSA scheme, why did it use secp256k1?
Couldn't ...
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What is one word seed word exactly?
I have the following code
import hashlib
import binascii
def word_to_private_key(word):
sha256_hash = hashlib.sha256(word.encode()).digest()
private_key = binascii.hexlify(sha256_hash).decode(...
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Is it safe to share half of the private key in WIF format?
Assuming I would generate my keys on https://www.bitaddress.org.
Is it safe to share the following four pieces of data?
One half of the private key.
The public key.
An SHA512 hash of the private key.
...
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197
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Why is the challenge scalar multiplied with the private key scalar In the Schnorr identification protocol?
If Alice wants to prove to Bob she is the holder of private key x, without exposing x, they can use the Schnorr identification protocol which has the public function sG = kG + exG and the private ...
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138
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Decrypting wallet
I'm seeking assistance with understanding the technical aspects of how Electrum wallets handle parsing errors and potential solutions for resolving them. My friend has encountered a recurring issue ...
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108
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Public key factors - but what's next?
Let's say I found (I know, impossible) public key factors. What to do with them next to compute original private key for that public key?
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Bulletproof++ as generic ZKP à la SNARKs?
My understanding is that the primary usecase for Bulletproof (BP) & Bulletproof++ (BP++) in elements is for range proofs for confidential transactions/confidential assets.
There seems to be a lot ...
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Probability of Generating a Bitcoin Address with Specific Starting and Ending Characters
I've recently come across a situation where scammers are generating (bitcoin) addresses that have the same starting and ending characters. This is concerning as many people, including myself, often ...
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Why doesn't Bitcoin Core use auxiliary randomness when performing Schnorr signatures?
BIP340 recommends using auxiliary randomness in generation of the Schnorr signature nonce, as follows:
Using unpredictable randomness additionally increases protection against other side-channel ...
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How can I manually (on paper) calculate a Bitcoin public key from a private key?
I am interested in generating a Bitcoin address by hand for security's sake. After I choose/generate a private key, how do I generate the public key?
From there, how would I double check my work?
...
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154
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Derive Secp256k1 curve public key starting off from known 32 bytes string
Starting off from a sha256 hash of a threshold pubkey, how can I generate a valid secp256k1 public key?
The challenge is that the 32 bytes of the hash does not always fall within secp256k1 range, so I ...
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What is the step-by-step algorithmic process to find the modular multiplicative inverse of (n-1) mod np, where (n-1) and np are not coprime?
Having perused the stackexchange, I found some similar questions, but am having difficulty understanding how to arrive at the solution to (n-1)*x=1 mod np, where:
n: Finite group order of the Bitcoin ...
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59
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Bulletproofs vs Merkle paths for inclusion proofs
In this blog post, Andrew Poelstra comments that bulletproofs can be used for efficient merkle inclusion proofs.
How would these proofs compare in size and verifying time to simple merkle paths? Take ...
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201
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What does it mean for an integer to be a member of secp256k1 group?
I'm reading the spending section of BIP47:
Alice calculates a scalar shared secret using the x value of S:
s = SHA256(Sx).
If the value of s is not in the secp256k1 group, Alice MUST increment the ...
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459
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How does this field multiplication in libsecp256k1 work?
I'm looking at libsecp256k1's codebase, for learning reasons (doubt I can contribute with anything useful there). While looking at the field implementation, the implementation of ...
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1
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233
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weak transaction in secp256k1
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 ...
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64
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Why does the Bitcoin network encrypt the transaction data? [duplicate]
The whole process of encryption sounds useless to me. Miners/validators and full nodes need to verify each transaction. They need two pieces of information:
The original transaction data
The ...
2
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1
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101
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Where is chacha20 and chacha_poly_aead used in Bitcoin Core?
In the source code of Bitcoin Core there are these functions but no explanation of how and where they are used. I need to make a description for all crypto-functions used in Bitcoin Core (https://...
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119
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How to encrypt messages with Pub/Priv keys
I'm wondering if it's possible to use the Bitcoin public and private keys (usually used for signing) for text encryption. This is an example in nodeJs:
import pkg from 'bitcore-lib'
const { ...
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216
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How does the BIP340 lift_x algorithm work?
Couple questions of code that I'm reviewing trying to learn schnorr sigs.
Why do we want an odd private key? I see even tests on the private key and then subtract it from the SECP256K1 Order to get an ...
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391
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Why bitcoin's generator point does not satisfy Elliptic Curve Cryptography equation?
This is my Python program:
Acurve = 0
Bcurve = 7
Gx = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798
Gy = 0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8
print(...
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87
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Is www.soloxbit.com a legitimate exchange? [duplicate]
help is needed urgently.
I have been invited to use a crypto exchange called www.soloxbit.com by a telegram group. I signed up as there was a 50% bonus on my first deposit using their referral.
My ...
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447
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Why g is 2 and 3 to derive the lambda and beta values for endomorphism on the secp256k1 curve?
As you can seen here, in hex, N and P are:
N = FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE BAAEDCE6 AF48A03B BFD25E8C D0364141
P = FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE FFFFFC2F
The ...
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What's the difference between the anti klepto protocol and anti exfil?
What is the difference between the anti-klepto protocol (also here) and Anti-Exfil? Is it the same thing just with different names or are there differences? It seems they are both addressing the nonce ...
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problem accessing wallet
I have a 2011 wallet.dat created in version 0.4.0 it accepts my password normally. but when putting in the current version of bitcoin core it doesn't work can you help me?
If I enter any other (not ...
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2
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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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What is the best way to check multiple crypto coins payments are paid - NODE JS
I am trying to write a gateway system where users can check the data upon the callback that is sent to their specific url.
I am wondering how I could go about checking that the payment has been ...
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234
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How do we know that Bitcoin supply is actually capped at 21 million?
Everyone says that the Bitcoin supply is capped at 21 million. But how did everybody come to this number? In Nakamoto's paper, I could not find this number. Can someone explain where it is or how we ...
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452
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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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2
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4k
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How is the generator point G chosen in the secp256k1 curve used in Bitcoin?
The generator point G in the secp256k1 curve used in Bitcoin is a known constant:
Gx = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798
Gy = ...
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Is it Possible to Create Signature Chains for Private Keys to Sign Transactions with? Similar to how Certificate Authorities Use Intermediate Certs?
I am wondering if it is possible to implement this flow with bitcoin private keys, similar to how certificate authorities have a root cert and an intermediate cert used to sign csr's. It would be ...
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128
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Is it possible to compute just a byte of the public key by having the private key?
Let's say we have a certain known public key to which we want to find the private key with a bad approach such as brute forcing.
Would it be possible that instead of computing the whole public key to ...
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107
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What needs to be changed in Bitcoin if SHA-256 is broken? [duplicate]
I come up with a little bit "catastrophical“ question. I declare that I understand the degree of improbability of such a scenario in our lifetime, but I would still be interested in your opinion. ...
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774
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What happens to the public and private keys after a transaction? Specifically, how (and why) do they change upon payment?
Feel free to answer/address as many of these topics as you like:
In particular, I am interested in how bitcoins can be stolen, e.g., the 2016 Bitfinex hack. If I am not mistaken, the only way to steal ...
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1
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140
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How transactions script work?
I am trying to learn Bitcoin in some technical details, but I don't really understand the process of locking and unlocking scripts. I know that for what they are using, but can someone explain me some ...
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149
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How do nodes fetch unconfirmed transactions?
I'm taking up a project to build a software in python to mine cryptocurrency (preferably bitcoin).
I have an overview of the computation that needs to be done.
I would like to know how nodes fetch ...
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1
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185
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BIP 32 CKDpriv not working in my python implementation
I have been working on implementing BIP 32 in Python. This is my code for deriving normal (not hardened) child keys as part of an HD_Key class:
def CKDpriv(self, index):
key = bytes.fromhex(self.c)...
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57
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how does new exchanges order books work?
When a new exchange is launched and it doesn't have many users, how does it managed an order book? how can they match orders when there's not enough of them?
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Can I be rewarded for discovering, creating, and proving bugs on Bitcoin?
There has never been a remittance history to this address.
https://www.blockchain.com/btc/address/1JqPFnGPhHhy54zJKmC1MPiczzgFjCmzE9
public key : ...
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1
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103
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BT wifi Internet router not detecting S9K miner
I am mining crypto via GPU & ASIC miners. I recently bought an S9K Antminer which powers on perfectly fine; however as we all know, it needs to connect to the internet via an ethernet cable. This ...
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1
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597
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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 ...
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93
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If you lose your Bitcoin wallet Password, can you simply transfer private key to another bitcoin wallet provider?
If you lose your Bitcoin wallet password, can you simply transfer private key to another bitcoin wallet provider? I mean if I lost the password to the website where the wallet is stored, can I simply ...
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