Questions tagged [cryptography]
Concerning the broad subject of cryptography and its narrow application in Bitcoin protocol and applications.
199
questions
-1
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1answer
16 views
Is IQmining worth the investment? [on hold]
I am interested in investing in crypto-contracts, is IQmining worth the investment?
0
votes
1answer
39 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
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1answer
32 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 ...
0
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0answers
23 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.
3
votes
2answers
296 views
To what extent does asymmetric cryptography secure bitcoin transactions?
Is there a specific attack or bug which asymmetric cryptography prevents during bitcoin transactions?
2
votes
2answers
96 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
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0answers
26 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
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0answers
35 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
30 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
41 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
148 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
55 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, ...
1
vote
0answers
32 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
54 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?
2
votes
1answer
67 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 ...
4
votes
1answer
65 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?
0
votes
1answer
58 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
votes
1answer
68 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 ...
2
votes
2answers
357 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 ...
0
votes
1answer
36 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
96 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
78 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
1answer
52 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 ...
1
vote
1answer
111 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 ...
2
votes
1answer
115 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
votes
1answer
80 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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votes
2answers
131 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 ...
0
votes
1answer
282 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
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0answers
35 views
Correct breakdown of the name of secp256k1?
sec Standards for Efficient Cryptography
256 256bit prime
k1 Koblitz curve no. 1
?
1
vote
1answer
152 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, ...
0
votes
0answers
19 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 ...
7
votes
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 ...
14
votes
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 ...
1
vote
1answer
51 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 ...
2
votes
1answer
389 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 ...
1
vote
1answer
58 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 ...
0
votes
2answers
42 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,...
0
votes
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 ...
0
votes
1answer
684 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 ...
0
votes
1answer
39 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 =======...
0
votes
2answers
55 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
votes
2answers
117 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 ...
-1
votes
1answer
61 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 ...
1
vote
0answers
151 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.
2
votes
1answer
30 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.
0
votes
1answer
70 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 ...
0
votes
1answer
31 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 ...
0
votes
1answer
44 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 ...
1
vote
1answer
157 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
...
1
vote
2answers
127 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 ...
