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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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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 ...
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0answers
5 views

How do I get inflation rate for crypto coins in csv format

I'm interested in doing econometric analysis of crypto coins and returns based on inflation rate. Any csv files that has all coins and inflation rate? Thanks.
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1answer
19 views

is it possible to encrypt the message with PUBLIC key and decrypt with SAME PUBLIC Key? [on hold]

In asymmetric cryptography, is it possible to decrypt the message with the SAME PUBLIC key with which the message was encrypted ? or message encrypted with public key can ONLY BE decypted with ...
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24 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 ...
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1answer
24 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 ...
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1answer
34 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 ...
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1answer
142 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 ...
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1answer
49 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, ...
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2answers
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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 ...
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4answers
170 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
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1answer
295 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 ...
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1answer
246 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.
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1answer
32 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 ...
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1answer
32 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 ...
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2answers
337 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 ...
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30 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 ...
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1answer
175 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 ...
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1answer
405 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 ...
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2answers
558 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 ...
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1answer
39 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?
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1answer
12k 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 ...
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0answers
51 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 ...
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2answers
115 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 ...
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1answer
41 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?
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1answer
126 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 ...
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1answer
61 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 ...
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1answer
29 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/...
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1answer
138 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 ...
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1answer
80 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 ...
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2answers
66 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 ...
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2answers
541 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 ...
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1answer
46 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 ...
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1answer
99 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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2answers
122 views

How would one prove he is Satoshi Nakamoto if he lost his private keys

Assume you're Satoshi Nakamoto, completely, and that you've forgotten your private key/s. How do you prove that this is true, using the BTC blockchain? Is there a transaction you can make, or a ...
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1answer
102 views

What is so special about chacha20 stream cipher along with poly1305 for message authentication codes?

I am currently trying to dissect the low level cryptography protocols of the lightning network and I realize that in many places chacha20 is being used. I tried reading about it in the Wikipedia ...
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1answer
56 views

ECDSA signature with r value of 31?

occasionally on Android we are generating an ECDSA signature. This turns out to have a "r" length of 31 bytes. Is that valid? For reference here is a nice diagram outlining the ASN.1 structure of ...
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2answers
149 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....
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3answers
891 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?
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0answers
26 views

Correct breakdown of the name of secp256k1?

sec Standards for Efficient Cryptography 256 256bit prime k1 Koblitz curve no. 1 ?
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1answer
143 views

How specific are ASIC's design? Can they single hash SHA256?

I understand that Bitcoin's ASICs are a highly optimized piece of equipment and, therefore, are also very specific. My question: are they able to do a single (or triple?) SHA-256 hash at all? And, ...
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0answers
16 views

Private Blockchains: Blocks’ validation

I’m a software developer and I’m trying to understand blockchain at a code level I have the following issue: There’s a private blockchain, this private blockchain does not have any relation to ...
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2answers
2k views

Is a bitcoin address collision possible if generating 90 million addresses every 4 hours?

I am running a test to see if I can obtain a successful bitcoin address collision after generating billions of addresses. I am not entirely sure how I would check them yet. Basically I have an extra ...
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2answers
561 views

What are the advantages of using Secp256k1?

Bitcoin uses secp256k1 as the specification for it's address system (https://en.bitcoin.it/wiki/Secp256k1). What are the advantages (and disadvantages) of using this over other specifications such as ...
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1answer
2k views

What is the origin of insecure 64-bit nonces in signatures in the Bitcoin chain?

In Biased Nonce Sense: Lattice Attacks against Weak ECDSA Signatures in Cryptocurrencies Joachim Breitner and Nadia Heninger use a lattice based algorithm to recover private keys from signatures in ...
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1answer
48 views

Security implications of removing CHECKSIG in a test

If I conduct an htlc transaction on testnet that does not include OP_CHECKSIG will it still cost an attacker more than (say) $10 in processing power or storage to subvert my tests? Details: I'm ...
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1answer
533 views

Ramifications of creating Electrum 2.x seeds which are not BIP39

Electrum 2.0 seeds (mnemonic phrases) are created with a checksum based algorithm (such that the hmac_sha512 starts with 01. It's usually a 13 word seed, but can be 12 in some circumstances. If all ...
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2answers
36 views

In theory could a pubkeyhash script be solved without the public key in the scriptSig?

When signing a pubkeyhash UTXO, it is required to provide both a signature and a public key. The public key is duplicated and one copy is provided to op_checksigverify to ensure the signature is valid,...
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1answer
52 views

Setup bitcoin-seeder

I wanna setup a dnsseed for a crypto currency using sipa/bitcoin-seeder on my VPS. The server is hosted at NetCup and running the software as root, and also listening on port :53 UDP. My domain is ...
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4answers
109 views

Use of proof of work in bitcoin

I am trying to understand what problem in bitcoin proof of work solves and came to this somewhat helpful quote: So, for instance, if a miner controls one percent of the computing power being used ...
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2answers
182 views

Block chain and its uses cases for a non-financial asset market

So i have been reading a lot about block chain technology and its use cases in the finance and cryptocurrecncy markets. One thing that guarantees blockchain's success in the cryptocurrency market is ...