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.
299 questions
4 votes
1 answer
732 views
How to crack ECC using halving
If I have a public key $P$ and if I could calculate the following values: $\displaystyle{P \over 2}$, $\displaystyle{P \over 3}$, $\displaystyle{P \over 4}$, $\displaystyle{P \over 6}$, $\displaystyle{...
- 43
2 votes
0 answers
95 views
Would an ECC break or CRQC be able to reveal relatioships between addresses in a wallet?
The very early bitcoin wallets used HKDF-type constructions (for every address belonging to a wallet) but then all crypto wallets moved to a construction where every address shared an ECC mathematical ...
2 votes
1 answer
343 views
Mapping points between elliptic curves
Let's say you are given an ellipitic curve defined over a finite field, with all of its domain parameters well-defined, e.g. the NIST curves. How can we go about defining a mapping between this curve ...
2 votes
0 answers
37 views
Understanding the Practical Implications of Multisignature Scheme Vulnerabilities
I'm researching the security models for multi-signature (multisig) schemes in various blockchain contexts. Specifically, what are some of the less obvious or recently discovered practical ...
0 votes
1 answer
230 views
In curve secp256k1, Bitcoin, what are the arithmetic steps to do mod p?
If the result of my point addition is point Q = ( x, y ) then what is the arithmetic to do the mod p? Is the mod to be done on x or y as soon as they exceed p? Maybe here is the answer. This is an ...
2 votes
0 answers
70 views
Recoverable ECDSA signature validation
I'm by no means expert in the area, so I apologize for any misunderstanding. I'm aware of the signing process, which ends up producing the values (r, s, v): r - x coordinate of k*G, where k is an ...
- 21
2 votes
0 answers
44 views
Why are two values (z, z') necessary for exculpability in this e-cash scheme?
I was recently looking into Chaum's E-Cash Protocol and its variations. I came across Formal Analysis of E-Cash Protocols by Jannik Dreier, Ali Kassem, and Pascal Lafourcade. The paper describes a ...
- 121
0 votes
1 answer
211 views
Nonce (r) Reuse and Private Key Security: A Risk for P2PKH Addresses?
I have a question regarding nonce (r) reuse in ECDSA signatures and the potential risk of private key leakage. Specifically, I'm looking into transactions using P2PKH addresses and whether reusing the ...
1 vote
0 answers
83 views
Can we efficiently solve the ECDLP if the j-invariant of an elliptic curve equals the field?
I have a scenario where the j-invariant of an elliptic curve is equal to the characteristic of the finite field over which the curve is defined. All other aspects of the curve appear secure, such as ...
- 11
1 vote
1 answer
148 views
How does the Related Key Attack on Schnorr Signatures work in real life?
We know that Schnorr signature is applied this way: Key Generation Define curve $E$, field $\mathbf F_q$, order $N$, generator $G$, and hash $h$. Private key: $d \in (0, N)$, Public key: $P = dG$. ...
- 163
0 votes
0 answers
93 views
Modular Arithmetic on Public Key
How can I multiply my secp256k1 elliptic curve public key by half the order of the curve modulo half the order of the curve? For instance, my public key is obtained by multiplying the generator point ...
0 votes
0 answers
30 views
How to identify a private key is odd or even from the (x,y) coordinate of the key? [duplicate]
Suppose k is a private key. Now using elliptic curve cryptography and scaler multiplication point point P(x,y) has been calculated from the private key k Now if I give someone point P(x,y). Will he/...
0 votes
0 answers
62 views
Is it possible to convert public key to private key if anybody can decode doubling to singling?
If a point is P then, P => Doubling operation => 2P If anybody can reverse it, i,e 2P => Reverse Doubling => P Will he/she be able to calculate private key from the specific public key of ...
- 125
1 vote
1 answer
119 views
Does FROST threshold signing go well with BIP340?
FROST is a popular threshold signing protocol for Schnorr-style signatures. BIP340 is a specification for an instantiation of a Schnorr-style signature scheme for Bitcoin Taproot. Specifically, they ...
- 697
0 votes
1 answer
77 views
How to determine large point for the same x axis in the elliptic curve cryptography?
For a given X value of elliptic curve cryptography there are two Y values. One point is P(x,y) and another point is Q(x1,y1) where P =-Q or Q = -P. Suppose given X value is ...
- 21