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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Determining the vulnerability of BTC in the presence of output RSZ with the entropy of mutual relations [closed]
I found the program as I understood from the description of the search for mutual entropy of different groups of RSZ output signatures from one wallet to bitcoin. Who has heard anything about this ...
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2
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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 ...
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What is the probability of accidentally getting a seed phrase that is associated with a real address with a balance in the bitcoin blockchain? [migrated]
Good afternoon! Such a question is interesting, and with what probability can you accidentally get a seed phrase that is associated with a real address with a balance in the bitcoin blockchain?
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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 (...
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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 ...
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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 ...
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149
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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 ...
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What is the probability of decrypting AES-128-ECB if some of the information is available?
There is a JSON array like this:
...
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43
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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 ...
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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 ...
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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:
...
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2
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53
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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 ...
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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 ...
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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 ...
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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 ...
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Why does compressed WIF generate a different address when importing to a wallet
I have a compressed WIF private key starting with K but when ever i try to import it gives a different address. What could the issue be. The address generated is correct for the private key as i do ...
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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 ...
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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?
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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, ...
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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 ...
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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 ...
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1
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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 ...
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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 ...
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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 ...
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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 ...
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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.
...
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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 ...
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211
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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 ...
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143
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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 ...
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501
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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 ...
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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 ...
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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 ...
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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 . ...
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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,...
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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 ...
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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 ...
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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?
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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\...
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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 ...
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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 ...
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2
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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 ...
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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@...
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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) ...
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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 ...
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bitcoin public address cryptography
I was learning about bitcoin cryptography and seen some strange bitcoin public addresses like this
1Lets1xxxx1use1xxxxxxxxxxxy2EaMkJ
1fuLL1xxxx1power1xxxxxxxxxxzatvCK
...
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1
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Can form of elliptic curve digital signature equation be simpler?
I am curious why equations for signing/validating with ECDSA have forms they have. Is it possible to use simpler equation that have same properties.
For example, this is an equation I found in the ...
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Is it theoretically possible to delegate public key generation?
Imagine the following scenario:
In a given cryptocurrency, privacy should be as high as possible.
For this purpose, a new account with a new address is created for every incoming transaction (the ...
2
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What is the difference between Solution-Verification and Challenge-Response variants of Proof of Work;
Sorry if question is really dumb, I am new to crypto :(
If the client provides the solution for the PoW Challenge-Response, in my understanding, the solution of that challenge should be verified. So I ...
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P256 seed problem
I'm reading up on elliptic curves and their history and it seems that people don't trust P256 seed which is defined in FIPS 186-3 on page 89 to be
SEED = c49d3608 86e70493 6a6678e1 139d26b7 819f7e90
...
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