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Questions tagged [cryptography]

Concerning the broad subject of cryptography and its narrow application in Bitcoin protocol and applications.

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3
votes
3answers
144 views

Are BTC Private Keys evenly distributed in 256bit space?

If we assume that there are ~2^96 private keys for EACH bitcoin address (2^256-160) and we assume that in cryptography it is considered good property of every hash function if it evenly distributes ...
-2
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0answers
21 views

Bitcoin ballet cold wallet ( card ) [on hold]

Ok so when using paper wallet you always want to get a new passphrase everytime you spend. I understand. But isnt the ballet keeping you on same passphrase? Isnt this less secure? It states its ...
3
votes
1answer
40 views

I need to know about wallets in cryptocurrency, how do exchanges generate deposite address per user?

In exchanges like Binance when a user wants to deposit coins in bitcoin or in other coins, per user receives a unique public key? Do they have to generate pair key private/public key for each user in ...
0
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2answers
83 views

Is there any blockchain explorer available to track the trades of cryptocurrency exchange?

I haven't seen any decentralized exchange that provides the information of trades and can track the record of transaction history and time. I am looking forward to that exchange which can provide ...
0
votes
2answers
218 views

Practical application of Electrum's Encrypt/Decrypt message feature?

It's pretty clear how signing a message with a Bitcoin key can be useful in proving ownership of funds. However, it's far from clear how encrypting a message with a Bitcoin key can do anything useful....
5
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2answers
4k views

How to generate Ed25519 public key from private key using libsodium?

Not all crypto currencies are using secp256k1 technology for keypair generation and digital signatures. Curve25519 technology (frequently used to support ECDH key exchanges) is being used by a few ...
0
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1answer
17 views

Learning to trade iOS user friendly crypto wallet safety when stored in and transfer for trading or use to purchase or get cashed

iPhone users best crypto wallet in bitcoin currency trading and transfer for easy access to use and keep safe deposit and profits as a new and first time trading experience to the trading crypto ...
4
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0answers
47 views

Can ECDH peers waste each other's time at will?

Peter Dettman notes that ECDH peers can waste each other's time at will. What does he mean? Can this be weaponized against Lightning nodes?
0
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0answers
21 views

What does Google's quantum supremacy mean to Bitcoin? [duplicate]

Recently, there has been a heated discussion on the internet about a paper published by Google on NASA's website saying that Google has achieved the so-called "quantum supremacy", which generates ...
0
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0answers
20 views

At what step does the private key is transformed to mnemonic phrase [duplicate]

If I am correct to make a private key you have to first generate a random 256 bit number then transform it to a WIF private key using base 58 check encode, does the mnemonic phrase is generated from ...
0
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2answers
60 views

I am just wondering what are the methods which can hide all the transactions and also able to validate transactions in an block chain?

I am new to block chain and was looking at how block chain work mainly proof of stake based . They check validity by going through all the transactions which is something concerning as everyone can ...
0
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0answers
35 views

BIP32 HD Wallet vs HMAC vs Hashing

I've been working on a website which will be caring out various cryptographic operations. On the website users can post Ads. Each Ad has a monotonically increasing unique ID. For each Ad, I would like ...
1
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1answer
266 views

Mycelium Backup Restore

Is there a way I can restore my mycelium Bitcoin wallet if I have forgotten the 12-word list? I have searched everywhere and no one describes a situation like this.
0
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1answer
106 views

how to place a bitforex api buy order

I have read the documentation for BitForex on placing a buy order here: https://github.com/bitforexapi/API_Doc_en/wiki/Order Then after understanding that, I read the API Call Description ...
0
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1answer
36 views

Can a cryptocurrency be liquid while it is in its pre-sale, or even ICO

I am planning to run a Coin's ICO for several years, not interested in the gains to be made from selling out ICO in 3 days NO, but interested in using the COin to end Global Poverty as i deem fit. So ...
0
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3answers
1k views

Why is it impossible to modify a transaction in the blockchain?

Many pages (including Wikipedia) say that it is impossible to modify a transaction which is already in the blockchain included. But why is it so difficult?
0
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1answer
186 views

Does each miner in a bitcoin mining pool has a chance to win the block reward?

Suppose there is mining pool XYZ. 10 miners 1 through 10 are subscribed to it and miners have varying hash power, some have 10 GPU mining rig while others have just a single CPU running 24 hours a day ...
6
votes
1answer
654 views

Recovering the last few digits of a Litecoin private key

Is it possible to recover the last few lost digits (10) of my Litecoin wallet private key? Are there any recovery tools available? Or will I have to try and roll my own? Crucially, what crypto ...
0
votes
1answer
479 views

How do I calculate the expected shares per minute for my pool

I am currently mining Zencash in a pool, and I'd like to be able to calculate the expected shares per minute for a given pool's hashrate. Let's say the pool's hashrate is 50 KSol/s. I think that the ...
5
votes
2answers
637 views

Is it possible to discover the set of bitcoin addresses from a public key?

I'm trying to find the set of bitcoin addresses from a public key associated with a user just to analyse this user transaction. Is there any way to derive/find all the addresses that have been ...
2
votes
2answers
40 views

How can I use messengers for crypto transactions?

Is it possible to use Signal or Telegram for crypto transactions? I heard CryptoCat messenger is for such needs, but interested in using those two mentioned above.
2
votes
1answer
85 views

How to make a homomorphic preimage/payment hash with current lightning network / Bitcoin implementations?

If I remember / understand it correctly by using the mechanisms from the scriptless scripts paper we could easily create homomorphic preimages / paymenthashes. I think this would be a very desirable ...
-1
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1answer
34 views

Is IQmining worth the investment? [closed]

I am interested in investing in crypto-contracts, is IQmining worth the investment?
0
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2answers
122 views

Do mining pools eliminate the need to store blockchain?

Suppose I want to design generic crypto currency miner starting from scratch . By generic I mean it can be configured to support a large number of available crypto currencies. This generic miner must ...
0
votes
1answer
43 views

Consider using Bitcoin but just heard the IRS is sending tax notices to 10k plus users

article: https://www.cnn.com/2019/07/26/tech/irs-cryptocurrency-taxes/index.html My background: Good understanding of RSA cryptography, some elliptic curve, Number Theory and I am a (real)programmer ...
0
votes
1answer
443 views

BITCOIN SCRIPT: Write the bitcoin ScriptPubKey script for a transaction that can be redeemed by anybody who supplies a square root of 1764?

Bitcoin script: For the following questions, you're free to use non-standard transactions and op codes that are currently disabled. You can use as a shorthand to represent data values pushed onto the ...
0
votes
1answer
33 views

How public-key cryptography secures bitcoin transactions from 51% attacks and Mining Attacks

I wanted to better understand how public-key cryptography avoids 51% attacks and mining attacks, also if this question is wrong please correct so that i can improve my research and provide me with ...
3
votes
2answers
301 views

To what extent does asymmetric cryptography secure bitcoin transactions?

Is there a specific attack or bug which asymmetric cryptography prevents during bitcoin transactions?
0
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0answers
24 views

What role does public-key cryptography play in bitcoin transaction? [duplicate]

Explain in one word and kindly tell what is it exactly that public-key cryptography does in bitcoin.
2
votes
2answers
97 views

Are there valid transactions which are impossible to mine?

Is it possible to have a bitcoin transaction T that is valid with a very generous transaction fee for which it is impossible for T to be included in the next block, or even in all subsequent blocks? ...
0
votes
0answers
38 views

How to integrate bitcoin address generator into website

I want to integrate a bitcoin accounts and address generator into my website, similar to those found on crypto exchanges. Users can generate addresses and have their own accounts. Is there an open ...
0
votes
0answers
42 views

Shamir SSSS how to split the example if i want to use 12 Bits instead of 11 Bits?

Shamir Mnemonics are encoded into 3 components - the Version, the Parameters, and the Shamir Share. The encoded components are concatenated together to form a Shamir Mnemonic. First Component is ...
0
votes
1answer
37 views

What's the purpose of CSHA256::Write and CSHA256::Finalize

Looking at Bitcoin Core implementation of SHA256, I noticed it was a bit different from OpenSSL's implementation. In OpenSSL, you would initialize a variable with SHA256_CTX when in Bitcoin Core it's ...
0
votes
1answer
61 views

Confused on using SHA256 code from Bitcoin Core

I was looking at Bitcoin Core code to use its SHA256 code but am confused on where I should be looking at. In bitcoin/src/crypto/sha256.h there is CSHA256 and in bitcoin/src/crypto/sha256.cpp there ...
4
votes
1answer
154 views

What are the 3 arguments called in function SHA256?

void sha256(struct sha256 *sha, const void *p, size_t size) { struct sha256_ctx ctx; sha256_init(&ctx); sha256_update(&ctx, p, size); sha256_done(&ctx, sha); } I'm trying ...
3
votes
1answer
64 views

ECDSA - why not using the cyclic additive group

As I understand things so far, the ECDSA scheme used by Bitcoin uses a group G generated by a point on the elliptic curve y^2 = x^2 + 7. Now G is a cyclic group of finite order n and is, hence, ...
0
votes
4answers
176 views

cryptocurrency tax question

I have a buddy who I sent money to to buy a certain amount of Ripple. For one reason or another, I couldn't do this on my own at the time. In any case, the currency has tripled and I want him to send ...
2
votes
1answer
478 views

Bitcoin Core Old Wallet.dat Vulnerability

Own a wallet.dat file from 2010-2011. Yesterday I saw there was a vulnerability which is makes attacking somewhat easier if your wallet is generated by old client and I'm pretty sure my wallet is ...
2
votes
2answers
398 views

How can my private key be revealed if I use the same nonce while generating the signature?

I know it is well understood that it is not a good practice to use the same nonce while generating the signatures, but I am not getting the math right. Assume I have some UTXOs that are controlled ...
1
vote
0answers
37 views

Schnorr Fiat Shamir Transformation

In the Schnorr identity protocol, we can transform the interactive ZKP into a non-interactive one by replacing the role of the verifier (i.e. providing a random challenge value) with a hash function ...
0
votes
1answer
65 views

How to verify signature of multisig transaction

How to verify signature of multisig transaction (2-2) after it being signed by first owner? How can I understand if that owner used wrong private key => wrong signature?
7
votes
1answer
15k views

Byte array to hexadecimal and back again in JavaScript [closed]

I can generate a byte array with var myByteArray = window.crypto.getRandomValues(new Uint8Array(16)) and I get 181,143,16,173,231,56,63,149,181,185,224,124,84,230,123,36 I can then turn this into ...
4
votes
1answer
101 views

Low-s value in bitcoin signature

What are the problems related in using the "normal" ( bigger than N/2) value of the s number in transaction signature and why we use the lower one? Is it about the math behind the ecdsa?
1
vote
1answer
177 views

What's the difference between xpub and bpub?

I've seen extended public keys such as the one below xpub661MyMwAqRbcFLCsW67CH9AgprkK2MbeLbmdMiBRWb1Wamm6GjGhTFQChvPmwQGQh78MMd8Eu7CLJ7FEuwhsomD66XC74VnfgHdEx1NFSKL But now I've seen a bpub ...
0
votes
1answer
72 views

Private key generation doubt

I read that the private key pk has to be any number between 1 and n, where n is almost 10^77. Since pk' s function is practically to be used as a scalar for multiplying the generator point G, why does ...
0
votes
1answer
48 views

Are transactions with the same ScriptSig a security problem?

For instance while looking at the transaction stack of my address, tracing it to exchanges I use, I came across this: https://www.blockchain.com/btc/tx/...
2
votes
1answer
99 views

What is the current computing speed of performing an elliptic curve multiplication?

Hi I was just looking for some information on how long it would take to crack a private key in bitcoin using a brute force approach and I couldn't find a very good answer for how long it takes to ...
0
votes
2answers
98 views

The order of the generator point G used in bitcoin

Hi I was just wondering how the order of the generator point G used in bitcoin was actually calculated. From the specification listed http://www.secg.org/SEC2-Ver-1.0.pdf for secp256k1 I can see ...
0
votes
2answers
622 views

C#, How can I actively query the crypto-market?

Are there any wrappers to get the real-time crypto-currency value similar to coincap.io? Right now I am using Json to deserialize a download string from CoinMarketCap, however, the api does not ...
0
votes
1answer
69 views

Bitcoin Signatures are susceptible to quantum attacks - how exactly and with what practical impact? [duplicate]

@PieterWuille wrote in another thread: "" The hashing algorithm is probably the most quantum-resistant piece of cryptography right now in Bitcoin. Barring any specific breaks, SHA256 and RIPEMD160 ...