All Questions
Tagged with ethereum or cryptocurrency
291 questions
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Why Can't I Use an Nacl Sign Keypair for Encrypt and Decrypt Operations?
I'm aware that the difference between the NaCL sign keys vs the box keys is that the secret key that comes from the NaCL box keypair is the ...
- 113
0
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2
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124
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Is "The only way to confirm the absence of a transaction is to be aware of all transactions" proven?
I have read the Bitcoin paper and there is one statement that I would like to know if it is really proven ir not:
The only way to confirm the absence of a transaction is to be aware of
all ...
- 41
1
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1
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288
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best encryption algorithm for encrypting a string
I am making a password manager , I am new to cryptography, so , can someone tell me if this can be a good solution?
1- the user inputs the email/password
2- all the payload gets encrypted with aes@...
1
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0
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222
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Assuming secp256k1 curve and given fixed (but random) $h$ and $d$ values, is it possible to calculate a $k$ such that $h\equiv(k\,G)_X\,(k-d)\pmod n$?
For generator point $G$ in the secp256k1 curve, I want to find a value $k$ such that:
$$h\equiv(k\,G)_X\,(k-d)\pmod n$$
where $n$ is the group order, and $(k\,G)_X$ indicates the x-coordinate (mod n) ...
2
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1
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88
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Before Bitcoin what was the motivation for researching key aggregation multisig and threshold schemes?
The motivation for key aggregation multisig and threshold schemes (e.g. MuSig(2), FROST etc) in Bitcoin is obvious. Signatures are a large part of every transaction, all the nodes on the network are ...
- 207
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3
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272
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bitcoin public address cryptography
I was learning about bitcoin cryptography and seen some strange bitcoin public addresses like this
1Lets1xxxx1use1xxxxxxxxxxxy2EaMkJ
1fuLL1xxxx1power1xxxxxxxxxxzatvCK
...
0
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1
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85
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Can form of elliptic curve digital signature equation be simpler?
I am curious why equations for signing/validating with ECDSA have forms they have. Is it possible to use simpler equation that have same properties.
For example, this is an equation I found in the ...
3
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1
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373
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Is it theoretically possible to delegate public key generation?
Imagine the following scenario:
In a given cryptocurrency, privacy should be as high as possible.
For this purpose, a new account with a new address is created for every incoming transaction (the ...
2
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0
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54
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What is the difference between Solution-Verification and Challenge-Response variants of Proof of Work;
Sorry if question is really dumb, I am new to crypto :(
If the client provides the solution for the PoW Challenge-Response, in my understanding, the solution of that challenge should be verified. So I ...
1
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1
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490
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P256 seed problem
I'm reading up on elliptic curves and their history and it seems that people don't trust P256 seed which is defined in FIPS 186-3 on page 89 to be
SEED = c49d3608 86e70493 6a6678e1 139d26b7 819f7e90
...
- 11
0
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1
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438
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Proof of Elapsed Time (PoET)
Proof of Elapsed Time (PoET) was discovered by Intel in 2016 as a consensus mechanism primarily for permissioned blockchain networks. Importantly, we can only use this concept in permissioned ...
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0
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52
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What's the best way to encrypt crypto seeds? [closed]
I would like to encrypt cryptocurrency wallet seeds (12 to 24-word passphrases) for replication and secure preservation. The seeds would be in a .txt or .rtf format before encryption. I would like to ...
- 11
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0
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39
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cryWhat algorithm are Trezor One and Trezor T using to sign messages? [closed]
My knowledge of cryptography is beyond shallow, and I have a problem I cannot solve.
Trezor wallets have two message signing formats: "Trezor" and "Electrum".
I have a method in my ...
- 111
1
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1
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190
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Question about Harden and Normal Key derivation
I am reading about Hardened and Normal child key in chapter 5 of the book "Mastering Bitcoin" by Andreas, along with this detailed thread and BIP-32. Here are some of my understanding about ...
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3
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1
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323
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two closely distanced ECDSA keys
Assume that one uses two private keys $x_1$ and $x_2$ to generate two public ECDSA keys $y_1$ and $y_2$ (e.g., used as public key for Bitcoin address). The distance between $x_1$ and $x_2$ is small (e....
- 109
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2
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2k
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Modulo p in Elliptic Curve Cryptography
To carry out Elliptic Curve Cryptography between parties, are all elliptic curve equations considered to be in the form $\bmod p$?
For example, the $secp256k1$ Bitcoin curve of the equation $y^2=x^3+7$...
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1
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1
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74
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Which application protocols use elliptic curve key recovery?
Section 4.1.6 of https://www.secg.org/sec1-v2.pdf describes a technique for recovering public keys from ECDSA signatures.
I guess Ethereum uses this. Like if you want to validate a particular ...
- 2,959
1
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1
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139
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zkSNARKS: What prevents the prover from chosing a different polynomial than the one he is expected to know
I am reading this explanation of zkSnark written by Maksym Petkus - https://arxiv.org/pdf/1906.07221.pdf
Here the Prover knows a polynomial of degree 3, 2 of the solutions of the polynomial are 3 &...
- 2,266
1
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1
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255
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Is this simple Proof of Work algorithm based on SHA256 susceptible to length extension attack?
Each block's contents are hashed into 32 bytes using $\operatorname{SHA-256}$ (call this string $a$). In order for the block to be accepted, there must be a 256bit nonce (call this string $b$) ...
- 123
14
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1
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5k
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Why "1" in 51% attack on Blockchain network
In many sources, included Wikipedia, we read:
Any pool that achieves 51% hashing power can effectively overturn network transactions, resulting in double-spending.
My question is: Why do we talk ...
- 243
3
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1
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110
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How would a malicious group of co-signers use a hash collision to sign an unintended message?
According to BIP340:
However, a major drawback of this optimization is that finding collisions in a short hash function is easy. This complicates the implementation of secure signing protocols in ...
- 31
0
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0
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199
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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 ...
- 1
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1
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169
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Is there anything stopping me from making my own NFT of an existing NFT?
I feel like I some understanding of cryptocurrencies, but what never made sense to me are NFTs. This is my current understanding of NFT's
NFT's are a type of smart contract
Smart contracts aren't ...
- 3
2
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1
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534
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How can I understand the math behind crypto, especially that used in blockchains / distributed ledgers?
A bit of a background about me; Computer Engineer but during my studies I didn't dive too deep into the maths, especially the crypto maths that is used to make the blockchain and cryptography work.
I'...
- 123
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1
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502
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Why are public keys derived from elliptic curve cryptography (ECC) and not from hashing?
I've just started studying Bitcoin and cryptocurrencies, so I might be wrong, but so far my understanding is that public keys are derived from private keys using ECDSA, in Bitcoin's case using ...
- 19
2
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0
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140
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Difference between fuzzy vault and fuzzy commitment?
https://dl.acm.org/doi/10.1145/2905055.2905118
Quoting the above paper's abstract, "Biometric cryptosystem can apply fuzzy vault, fuzzy commitment, helper data and secure sketch, whereas, ...
- 121
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0
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59
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Does the number of bits in the block nonce influence the security of the blockchain?
I know that Bitcoin uses a 32bit nonce that miners iterate over trying to hit the target number of prefixed 0's in the hash. If they run through all 2^32 combinations they then change something else ...
- 123
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0
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86
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Literature about cryptography and programming on c++ [closed]
I'm interested in learning about cryptography and making something practical out of it - make own cryptocurrency sometime im future.
I think I have good knowlegde of c++, I learned from learncpp.com ...
- 11
2
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1
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839
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Which passphrase length is good so it's hard to break bitcoin's PBKDF2 key?
According to https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki#From_mnemonic_to_seed
To create a binary seed from the mnemonic, we use the PBKDF2 function
with a mnemonic sentence (in ...
3
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1
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187
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DIY TRNG on an embedded system for Ethereum private key generation
I'm trying to build this Ethereum hardware wallet on a custom designed embedded system and I'm no expert. Googling around I found this Robust, low-cost, auditable random number generation
for embedded ...
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0
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39
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Is a truly p2p ledger (cryptocurrency) possible?
Is a truly p2p ledger possible, where there is no need for a third party (or a number of third parties) to verify ledgers.
Probably a system where the two parties who don't trust each other can verify ...
- 13
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0
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62
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Private Key from Extended Private Key and Public Address [closed]
Is it possible to generate a private key from a public address and an extended private key?
For context: I am using C# and NBitcoin. The public address is generated from the outside via an extended ...
- 11
2
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1
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209
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How does hardware wallet recovery work?
I'm investigating hardware cryptocurrency wallets and am trying to understand how recovery works from a technical point of view. These wallets typically provide a 24-word "recovery seed" ...
- 123
1
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1
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783
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Are zk-STARKs really quantum resistant?
I see lots of mention that zk-STARK proofs that are being developed notably for use in blockchain networks are labelled as "quantum resistant". Many articles and reports that state this, ...
- 199
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1
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263
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How to pad in the SHA256 Algorithm (an example using Bitcoin Header)?
For any bitcoin block we combine various Header fields to create a string which is an input to a 2 pass SHA algorithm. The resultant hash must match with the Hash in the Block header for the Block to ...
- 151
0
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1
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644
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Related Key Attack on Schnorr Signature - Why does the challenge include $\psi = g^x$, not $y$?
The original Schnorr signature scheme suffers from a Related Key Attack (RKA) as described by Morita et al. The authors of this paper then suggest a modification to the signature algorithm to prevent ...
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1
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1
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300
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How to generate a random string in Python for a mission-critical application
I'm trying to figure something out, but it is difficult for me. I need to generate a fully random string in Python. My current function is attached below. I just want to know whether this is secure ...
-2
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1
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109
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Bitcoin energy waste
Reading learnmeabitcoin I found the following how bitcoin works:
The bitcoin difficulty self adjusts so that a block is solved on average in 10 minutes.
Solving a block requires the miner to generate ...
- 99
0
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1
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94
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What hash structure is Facebook Diem using?
Some cryptocurrencies use fixed values in some positions in the resulting hash, like a fixed amount of initial zeros. What fixed positions and fixed values are Facebook Diem using?
- 123
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0
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46
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Is it possible to provably make cryptocurrency tokens inaccessible?
Would it be possible to generate an agreed upon public key that has no corresponding private key (maybe by using the latest few block hashes of a blockchain) and then send cryptocurrency to that ...
- 11
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226
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What are the algorithms used in Facebook's Diem algorithm?
Facebook plan a new cryptocurrency release called Diem. What algorithms are used? What output size is used for the hash function?
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1
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99
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is it efficient if blockchain uses double Hash algorithms $H_1$ and $H_2$?
I wonder is it efficient to use less Target condition and double hash algorithms with different target (or the same target with different Hash algorithms) and one nonce in a Block.
Example
Target 1 ...
- 503
1
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0
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74
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Moving a monero wallet+ node from a disk to another one [closed]
I dont know where to put this question, and the most appropriate would be here i guess, i found no criptocurrency stack, if its not here i would apreciate a link to post this
I've downloaded a monero ...
- 111
1
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1
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546
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BIP 39: If I mix my 24 seed phrase with another 24 words, will the checksum property allow an attacker to retrieve the original seed phrase?
Assume that I have a 24-word passphrase that I want to store securely but online by mixing it with another 24 words in a manner only I know. Does the checksum property somehow help an attacker to ...
- 13
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1
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207
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Fully understanding bitcoin transcation verifying and secp256k1
Hello fellow cryptographers.
I have spent last few days trying to understand and find a way to generate secp256k1 private and public keys from scratch, but i failed.
I have seen tons of videos and ...
1
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0
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24
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minimal trading amount per transaction, looking for exchange [closed]
I currently developed crypto bot with support of low transaction estimate to buy/sell. Now I am looking for exchange allowing to buy all possible pairs for under a \$1 or even less. Let's say BTC/USDT ...
- 111
1
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0
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27
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Can Litecoin & Bitcoin have overlapping Transaction Ids (txid) [closed]
Im currently coding my own transaction lookup page for cryptos. Since Litecoin and Bitcoin are so similar to their txid. I wanted to ask if its actually possible that these 2 currencies have ...
- 11
1
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2
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204
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What are alternatives to Proof of Work for consensus of a blockchain that doesn't contain anything of value?
For example, a distributed blockchain that would keep track of the weather. Anyone could add a weather reading, and several of these would be stored in each block, just like transactions in a ...
- 11
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1
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1k
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Calculate private key from public key and r [closed]
I watched this video where somebody finds bitcoin wallet private keys using only the "sigR" value and the public key using a python script named "formula".
How does this work and ...
0
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2
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487
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Encrypting cryptocurrency seeds for cold storage
I’d like some feedback on an encrypting algorithm. I’m not rolling my own, but even putting together well-proved pieces may create many pitfalls. (I don’t know if I'm stretching questioning in this ...
- 103