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Questions tagged [cryptocurrency]

A cryptocurrency is a digital currency powered by cryptography. This tag is applicable only to Q&As about the CRYPTOGRAPHIC MECHANISMS used by a currency, not for questions about economy, usage, or acquisition of any particular currency. The latter kinds are unwelcome. Please note that Stackexchange has dedicated websites for Bitcoin, Ethereum, Monero, etc.

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Bitcoin Generation [migrated]

In a blockchain network with number of parties, how are the number of bitcoins held by each party decided in the initial stage? Example: If there are 4 parties A,B,C,D who decides/generates the ...
Crypto_researcher's user avatar
-4 votes
1 answer
51 views

How to check balance of big number of bitcoin private keys easily? [closed]

I have 86400 bitcoin private keys. Within these keys there is high chance of getting 4 btc. I am not jocking. All keys are important. I have checked some. Example: ...
Asif Iqbal's user avatar
2 votes
0 answers
47 views

Efficient NOT in set proof?

I am looking for a solution for a very specific problem, I have one, but I am not statisfied with it and it feels there must be a much more efficient way to do this. I have a hashed value of 256 bits. ...
ovanwijk's user avatar
  • 155
0 votes
0 answers
29 views

i want to verify the following p2pkh transaction

I know to veify the p2pkh transaction we have to place the unlocking script and locking script in a stack and than evalute the stack. In such cases the the scriptpubkey_asm is of the form <OP_DUP ...
Code's user avatar
  • 1
1 vote
1 answer
68 views

How should I map E'(Fp6) --> E'(Fp) starting from Bitcoin public key coordinates(x,y)?

Let $p$ be the prime number 115792089237316195423570985008687907853269984665640564039457584007908834671663 and let $E$ and $E'$ be the curve equations $$E(\mathbb ...
bnsage123's user avatar
0 votes
1 answer
61 views

Can I construct a incomplete Merkle Tree without denting its security?

...
Chirag Parmar's user avatar
3 votes
1 answer
724 views

Is AES a group?

The question I'm wondering is whether the AES cipher is a closed cipher (which is equivalent to AES being a group). And this question interests me due to the lack of understanding of whether it is ...
Ss1996's user avatar
  • 53
4 votes
1 answer
2k views

In Bitcoin, given half the 52-character private key in WIF format, is it possible to reconstruct the whole private key?

Given the following two preconditions: It is almost impossible to reconstruct a bitcoin private key if an attacker only has one half of the private key as well as the public key. It is almost ...
Ohumeronen's user avatar
-1 votes
2 answers
222 views

If it is proved that P=NP, what happens to crypto? [duplicate]

If various PKC is shown to be not NP=Hard, what happens to crypto? More importantly, what happens to crypto wallets? If it is shown that P=NP for many currently assumed to be hard problems, but ...
Zekchelovek's user avatar
2 votes
1 answer
129 views

In NIZK, what is the difference between "transparent“ and “without trusted setup”?

When I study a zk-SNARK scheme, the scheme claims to be transparent. Does this mean that this scheme does not require a trusted setup? Furthermore, if a NIZK scheme includes a Common Reference String (...
user109993's user avatar
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0 answers
59 views

Interacting with Zksync sometimes returns an "invalid value for value.blockHash" error

I've been sometimes getting this error while interacting with zksync "invalid value.blockHash" and have been unable to find information about it elsewhere. What's curious to me is that it ...
Javier Cabrera's user avatar
-1 votes
2 answers
285 views

Formula for deriving the x-coordinate using the y-coordinate (decompressing a compress public key)

According to my understanding a public key is made up of x and y coordinate and a compress public key is made up of the y-coordinate since it's possible to directly calculate the uncompress public key ...
Aviril Smith's user avatar
1 vote
1 answer
194 views

Deriving of the y-coordinate on secp256k1 elliptic curve

...
Aviril Smith's user avatar
1 vote
0 answers
39 views

How can the validity of signatures in layer-2 transactions be proven in zk-rollup?

I have many questions about the details of using zk-SNARK technology in zk-rollup: How can the validity of signatures in layer-2 transactions be proven in zk-rollup? In zk-rollup, is a single large ...
user109993's user avatar
1 vote
1 answer
171 views

What is the probability of decrypting AES-128-ECB if some of the information is available?

There is a JSON array like this: ...
accountnujen's user avatar
0 votes
0 answers
47 views

Practical deployments of ECC with cofactor of elliptic curves $4$ or $8$?

Are cofactor $4$ and $8$ ECC schemes widely used in practical deployments such as those in cryptocurrencies? Can you name some practical settings where there curves are used and cryptocurrencies where ...
Turbo's user avatar
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-7 votes
1 answer
58 views

In the context of a blockchain-based digital currency, I have some questions regarding the functionality and operations of a particular system

Could you clarify where the stack object is typically generated? Is it created on the sender's device or the recipient's device? If I send funds to a multipay stack that was created on another device ...
Hcomber's user avatar
0 votes
0 answers
39 views

The specific nature of a 51% attack - in relation to a multiple choice question that I was marked as incorrect on

In a course I'm taking the following question came up: ...
phoenixestant's user avatar
0 votes
2 answers
65 views

Proof generation in zk cryptocurrency

In a cryptocurrency with privacy e.g., zcash, where does proof generation take place? Can it happen in the client's device every time a transaction is performed? If it happens in client's device, are ...
learner1's user avatar
3 votes
1 answer
238 views

Does PBKDF2 HMAC 512 really only produce a maximum of ~128 bits of entropy? Regardless of input?

Andreas Antonopoulos effectively states: an input of 256bits of entropy into PBKDF2-HMAC-SHA512 will ONLY output a 64 byte hash containing ~128 bits of entropy. He states the algorithm essentially ...
George's user avatar
  • 33
1 vote
0 answers
195 views

Quantum-safe algorithm for hiding cryptocurrency transaction amount [closed]

I have a decentralized coin system that I am trying to develop. Each coin can be split up into 1,000,000 units. I've been looking for a quantum-safe and practical (efficient) algorithm to send ...
rapt's user avatar
  • 91
1 vote
0 answers
36 views

Ethereum signature as xml-dsig11

This question was originally posted in https://ethereum.stackexchange.com/questions/151471/ethereum-signature-as-xml . I post it here aswell because I rarely get any response there. I am seeking to ...
lash's user avatar
  • 111
4 votes
1 answer
184 views

ECDSA (ecrecover) - How an attacker can construct a hash and signature that look valid

I found information, that it is possible to construct a hash and signature that look valid if the hash is not computed within the contract itself (we are talking about ECDSA/ecrecover here). So, the ...
Andrew Rukin's user avatar
1 vote
1 answer
76 views

Can the last n bitcoin blocks (including transactions) be reliable enough to be used as a seed for a PRNG or an input to a crypto hash-function?

Suggested by u/HolgerBier on reddit Is it unpredictable enough or too difficult to manipulate (as in more than a few hundred million USD) to have a sequence of blocks?
TheReal_Skywalker's user avatar
2 votes
1 answer
166 views

Provably secure cryptography in blockchains

Do you know a blockchain that does not use at all cryptographic primitives standardized by USA or other countries? It is strange to me that the security of many cryptocurrencies is based on ciphers, ...
Dimitri Koshelev's user avatar
2 votes
0 answers
23 views

Which channel protocol should I use to broadcast the message between parties?

I am building the Threshold Signature Scheme (TSS) based wallet. I would like to run the each party's node separately with different host. And these nodes should be able to send the messages through ...
thant zin tun's user avatar
1 vote
0 answers
94 views

Can we reduce the size of the XMSS signature?

As XMSS is post-quantum we can use it to secure blockchain. One of the main disadvantage of XMSS is its signature size. If we can reduce the size of the signature then we can use XMSS in the ...
Anantashayana Hegde's user avatar
1 vote
1 answer
60 views

ZKP vs disposable addresses [closed]

In other words, what does ZKP brings on top of the practice of not reusing addresses? From my research, ZCash is currently a state of the art example of ZKP application, but what extra benefits does ...
Jp_'s user avatar
  • 111
1 vote
0 answers
63 views

Secure permutation of $E(\mathbb{F}_q)$ as a set for an elliptic curve $E$ over a finite field $\mathbb{F}_q$

Let $E$ be an elliptic curve over a finite field $\mathbb{F}_q$. For simplicity, let the group $E(\mathbb{F}_q)$ be of prime order. Assume that I know how to construct an efficiently computable ...
Dimitri Koshelev's user avatar
1 vote
0 answers
48 views

In Zcash, how does a recipient look up which transactions belong to him/her?

For Monero, the scheme for stealth addresses is pretty straightforward. (For example: https://monero.stackexchange.com/questions/1500/what-is-a-stealth-address) However, I haven't found any details on ...
frt132's user avatar
  • 23
-1 votes
1 answer
52 views

Zero knowledge proof to validate/invalidate a claim

Have a look at the Twitter conversation below in the screenshots. @theveveshow asks if @trader1sz has sent ETH to the girl in question? @trader1sz responds that the girl in question has indeed sent ...
Mogambo's user avatar
  • 11
1 vote
0 answers
37 views

How does the Mongomery Algorithm work? [closed]

can someone please explain to me what's the role of montgomery reduction algorithm and how to implement it in python. I wrote the code below to calculate a*b mod m but it doesn't seem to work well. ...
meran_kud's user avatar
1 vote
1 answer
96 views

How to Ensure Security in a Gaming Peer to Peer Network

I've been recently thinking about building a c++ poker game that would let players to play over sockets in a peer to peer network. However I do not know how security would be ensured. I was thinking ...
Kiran Manicka's user avatar
1 vote
0 answers
333 views

Understanding seed phrase, private key, wallet addresses

I have a question about Cryptocurrency wallets like Metamask (soft) or Ledger (hard). How is a 12 or 24 word seed phrase enough to show the same crypto addresses in any crypto wallet that supports the ...
HankCa's user avatar
  • 139
2 votes
1 answer
201 views

How to implement a "viewing key" for secrets proved by zero knowledge proofs?

In ZCash, Monero etc, the sender/receiver addresses as well as transaction details are hidden. However, with a viewing key, a third party can see the exact details of the transaction or all ...
toga's user avatar
  • 21
2 votes
0 answers
721 views

ECDSA Common Nonce Reuse Attack

so I recently stumbled upon this video by @bertcmiller who created two transactions with the same nonce "k". That seen I researched quite a lot of pages explaining how to recover the private ...
Robert Bahn's user avatar
19 votes
1 answer
5k views

Will IBM's Condor quantum processor run Shor's Algorithm to crack a 256-bit Elliptic Curve key?

Yesterday IBM announced that they have a 433 bit quantum computer, called Osprey. There is nothing in the press releases I can find that says whether it can or cannot run Shor's Algorithm. They also ...
Simon G.'s user avatar
  • 343
0 votes
1 answer
211 views

Is it impossible to extract any data from an ECDSA signature of hashed data

I am trying to write a function that, given an EIP712 ECDSA signature, verifies the signature was signed by a particular person, and then (somehow) retrieves the information that is encoded in the ...
Barney Chambers's user avatar
-4 votes
1 answer
512 views

Compressed Address public key [closed]

Is it possible to get the x, y of the compressed public key? I have decompress it and naturally it gives the xy of the decompress public key. I need the xy coordinates of my compressed public key . ...
Roy Nahar's user avatar
2 votes
1 answer
755 views

How does Ethereum BLS signature verification works?

I am implementing BLS signature verification on smart contracts and I have a question regarding the way that Ethereum verifies the signature. Recall that bls signature works as $e(P_2,H(m)_1)_T=e(G_2,...
blockByblock's user avatar
0 votes
1 answer
2k views

Finding the private key with the transaction signature [duplicate]

I have two ETH transactions (both belonging to the same address) that both have the same r value in the transaction signature, is it possible to extract the private key from it? Details of both ...
Hossien Basuli's user avatar
0 votes
1 answer
57 views

Is there any way to ensure that a network merge, after a parition, never causes disagreements?

Background: A cryptocurrency, such as Bitcoin, have a global order of all transactions that is guaranteed to be agreed by all participating nodes. With Bitcoin, this is ensured by making the longest ...
caveman's user avatar
  • 573
2 votes
0 answers
297 views

Are digital signatures a type of zero-knowledge proof?

Are the digital signatures used in cryptocurrencies such as Bitcoin a type of zero-knowledge proof?
CHONG ZHAO XIAN's user avatar
2 votes
1 answer
146 views

How easy is it to know how many preimages an image might have, given that there's at least one (preimage, image) pair?

I have been considering an approach to incentivize cryptocurrency miners to verify claims of quantum computational supremacy. Briefly, miners find collisions $f(x_1)=f(x_2)=y$ of some known $f:m+1\...
Mark S's user avatar
  • 289
-1 votes
2 answers
152 views

Allow decryption key to be known only after a certain time [duplicate]

We have a smart contract containing encrypted data that should remain encrypted till a specified timeLimit. Then, the decryption key would be made public, for everyone to read that data. We want to ...
explorer's user avatar
1 vote
1 answer
577 views

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 ...
planet-pranav's user avatar
0 votes
2 answers
104 views

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 ...
Prankster2k's user avatar
1 vote
1 answer
237 views

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@...
alwaysInTheBasement's user avatar
1 vote
0 answers
214 views

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) ...
J. Smitherson's user avatar
2 votes
1 answer
77 views

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 ...
Michael Folkson's user avatar

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