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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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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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1answer
25 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
85 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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1answer
39 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 ...
3
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1answer
35 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
110 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
79 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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21 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
131 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
14 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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1answer
1k 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
45 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
132 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
43 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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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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2answers
38 views

How bitcoin gets monetary value [duplicate]

This looks like a complex thing but I am trying hard to understand it. Why would any one in the world honor a crypto currency till it is backed by a government with monetary value? How does a crypto ...
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1answer
307 views

Looking for code generate bitcoin address from passphase in C++

i'm try to write a program which generate bitcoin address from given hash sha256 of passphase as private key or given hex private key. I've found a library for this but it required Boost package in ...
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1answer
37 views

Is hashing an optional step to use with public key cryptography for blockchain

I am confused by the public key cryptography versions that I've read so far. Are the steps optional, dependable on the types of blockchain or they are referring to different methods? Version 1 =======...
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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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2answers
79 views

How to get the generator G point for any new curve?

I have this bitcoin curve: y^2 = x^3 + 7 but the finite field Fp is modified to be: n=115792089237316195423570985008687907853269984665640564039457584007908834675927 1-What is the G point? 2-how ...
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1answer
55 views

proof of stake concept and implementation confusion

i'm currently studying proof of stake concept in cryptocurrency in preparation of building it soon, but i still have some doubts about my understanding of the concept itself, and i have a lot of ...
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118 views

Idioms of use/ bitcoin heuristic

I already know the answer of a) part which is Alice. Can anybody help me in finding answer of b) part.
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1answer
25 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.
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1answer
40 views

Can Bitcoin Tech be Used to Protect Journalists [closed]

Over eight Nigerian journalists are currently in police detention because they published investigative news stories that didn't sit well with the government of the day. How can the bitcoin ...
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1answer
30 views

Have all hashes of unlocked difficulty levels of cryptocurrencies been mined?

I'm wondering if all the hashes of a previously unlocked difficulty level of a cryptocurrency, such as 0000000000000000xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx BTC , have been completely ...
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1answer
34 views

Multisig Wallet Question

I think I understand multisig wallets: X out of Y signatures are required for a transaction to be made. My question is: is there such a thing as a multisig wallet where any ONE of the allowed ...
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1answer
70 views

What's the difference between xpub and bpub?

I've seen and extended public key such as the one below xpub661MyMwAqRbcFLCsW67CH9AgprkK2MbeLbmdMiBRWb1Wamm6GjGhTFQChvPmwQGQh78MMd8Eu7CLJ7FEuwhsomD66XC74VnfgHdEx1NFSKL But now I've seen a bpub ...
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2answers
49 views

Is there a single point generator G for every elliptic curve?

I understand that G is a point on curve which holds true for y^2 = x^3 + ax + b. But there can be several other points as well which holds true for above equation but how do we choose which one is our ...
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0answers
38 views

Could a network described below function and how well?

I have an idea I am working on for some time, it would be using blockchain technology. However, although I know something about blockchain as it stands today, I am lacking a more deepened knowledge ...
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1answer
155 views

What is the difference between digital signature and a digital fingerprint?

I've been reading the book, Mastering Bitcoin by Andreas M. Antonopoulos, in chapter 4, the cryptography used in bitcoin is classified as: keys, bitcoin addresses and digital signatures. I understand ...
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0answers
113 views

Would it be possible for an 8-bit microprocessor to create a bitcoin keypair?

Context for question: With the latest security breaches around modern CPU's (Spectre / Meltdown) I was wondering if we could generate ECDSA keypairs on cheap, small and/or simple air gapped (micro)...
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3answers
392 views

Public key cryptography question - Is Private or Public key used to sign? Confusion between which key is used to sign and which is used to encrypt

I am relatively new to cryptography and blockchain and am learning about how public key cryptography works, and its application in Bitcoin's environment. I read two different articles , the 1st which ...
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0answers
38 views

Error found while doing transaction in Ripple as [RippledError(noNetwork)], Although server_state is full

I am doing ripple transaction and found error as [RippledError(noNetwork)], although my server_state is full in mainnet.. Kindly help me in resolve this issue. Below is my server_info command output. ...
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0answers
28 views

Mining beginner asking for advice of what coin to mine

I am new to mining and have recently purchased the following equipment to create my first mining rig: Motherboard: Asrock H110 Pro BTC+ GPU: Nivida GTX1060 Windforce 6GB GDDR5 X6 PSU: Supernova G3 ...
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2answers
123 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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1answer
658 views

SECP256K1 Minimum Value for Private Key

I've been looking into Elliptic Curve Cryptography, in particular the SECP256K1 spec which is used in Bitcoin and Ethereum. So I understand that the Generator point G is fixed based on the spec and ...
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3answers
593 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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2answers
393 views

BIP32 recommends a 256 bit seed. Why do most Bitcoin wallets only use a 128 bit seed?

According to BIP32's "Master key generation" section, "256 bits is advised". See https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#Master_key_generation Why did BIP32 consider 256 bits ...
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1answer
1k views

Cryptocurrency Exchange Technical architecture? How to build it? (Developer Point of View) [closed]

I'm a softawre developer & newly involved in Blockchain Technology. I need information about How Cryptocurrency Exchange Technically work? i.e Buy ETH using BTC or exchanging any coin with ...
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0answers
246 views

Ed25519 Successor to ECDSA in Bitcoin?

Bitcoin is currently using the secp256k1 curve. Understand that Ed25519 is technically superior -- i.e., offers better security than ECDSA and DSA, speed and most importantly, I think, resistance ...
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1answer
338 views

How can I create uncompressed public key in C++?

I need to derive public key from my private key in uncompressed form. I know how to create compressed one with libbitcoin, but I can't find appropriate method for uncompressed form there. Are there ...
5
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1answer
133 views

what is a discrete logarithmic assumption? how does it set-up trustless proofs?

pending proposal of bulletproofs as a zk proof for confidential transactions relies on fiat-shamir heuristic to be non-interactive via creating a digital signature on interactive proof of knowledge ...
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1answer
372 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 ...
2
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1answer
58 views

Needed maths for full understanding

I often come across papers written in the Bitcoin space involving some math that I am not formally versed in. Could anyone point out general topics in math that I should have a formal grasp on in ...
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1answer
33 views

While creating new crypto using fork need to generate smart contract? [closed]

I have 2 questions for creating nee crypto currency using fork. 1.) I have created one new crypto coin which is called mindcoin, now should i generate smart contract for deployment my currency in ...
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1answer
20 views

hello, need some help [duplicate]

Who is responsible for ensuring that the bitcoin protocol is not violated in the network? 1. The market forces behind the supply and demand of bitcoin 2. Miners 3. Consensus of the miners ...
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1answer
48 views

How important is the hash power in solving a block?

What is the role of hash power in solving a black, I have read at numerous place it's more like a lottery to successfully form a block in bitcoin and any such crypto blockchain currencies. Is it ...
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1answer
74 views

Solving a Block with more than one miner connected to same daemon

Well excuse me in advance if my question sounds funny. But I'm just curious perhaps someone can shed a light. When in a pool of miners, let's say there are 100 miners connected to a single daemon ...
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1answer
30 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 ...