Questions tagged [schnorr-identification]
The Schnorr Identification Protocol relies upon the security of the Discrete Logarithm Problem. Schnorr's protocol was introduced after, and is comparable to, the identification protocol of Fiat and Shamir and that of Guillou-Quisquater.
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How to make the interactive Schnorr identification protocol become non-interactive
I am reading about ZKP and I found this interesting question about changing this protocol from interactive Schnorr identification protocol to non-interactive and I need help in solving it :
Peggy (...
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1answer
230 views
Sigma protocol for AND-composition involving the same secret
Say we have two public cyclic groups $G_1$, $G_2$ of corresponding prime orders $p_1$, $p_2$, and known generators $g_1$, $g_2$.
Say $g_3$ is also a generator of $G_2$.
For publicly known $C_1$ and $...
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1answer
95 views
What is difference between an identification scheme and a digital signature scheme?
It seems we can use every identification scheme to sign and verify a message and vice versa. I am right or not? What is difference between an identification scheme and a digital signature scheme?
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Schnorr signature using discrete logarithm / problem with python implementation [closed]
For educational purposes (by purpose with small values for the prime order q), I tried to write a small Python implementation of the Schnorr signature described in the Wikipedia article https://en....
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2answers
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Schnorr identification protocol security proof
I read about security proof of Schnorr identification protocol against impersonation attack. For the sake of comprehensibility let me sum up the protocol: Given group $G$ with generator $g$. Verifier ...
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1answer
101 views
The danger of Hash collision in Schnorr NIZK
We use Fiat–Shamir heuristic to turn Schnorr ZK to NIZK. So now NIZK is secure against chosen message attacks in the random oracle model, that is, ideal hash function: every unique query leads to a ...
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0answers
79 views
Schnorr identification scheme without changing k flaws
The Schnorr identification scheme is being used to remotely log into a home computer which has stored $p$, $α$ and $β(\equiv α^a(mod p))$ - with $a$ the password. This works thusly:
1) The user ...
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0answers
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Prove of identity by signature scheme
Let $\Pi = (\mathrm{Gen}, \mathrm{Sign}, \mathrm{Vrfy})$ be a signature scheme, which is existentially unforgeable under adaptive chosen-message attacks. (Assume such a scheme exists.) Consider the ...
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1answer
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Understanding the definition of Schnorrs identification protocol
I have some trouble in understanding the definition of Schnorr's Identification protocol. The is the definition that I received:
Prover and verifier agree on a cyclic group $G$ of prime order $q$ ...
2
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1answer
166 views
Plausible Deniability in Schnorr
How does a dishonest verifier affect plausible deniability of the interactive Schnorr protocol?
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1answer
146 views
Security proof of partially blind signature (schnorr signature based)
I read a representative paper about partially blind signature.
Abe and Okamoto - "provably secure partially blind signature".
They suggested a partially blind signature scheme based on Schnorr ...
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4answers
583 views
Schnorr protocol: how does malicious verifier win?
My question is about the challenge space size in Schnorr protocol. To be precise, I feel I've read all the Internet (twice) and I still don't understand why is it bad to allow challenge space to be ...
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1answer
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How we can create a protocol using Schnorr as identification scheme and a hash function as a puzzle?
My question has to do with the creation of a PoWorK( Proof of Work or Knowledge) protocol.How we can create a protocol like this ,using Schnorr as the underlying CVZK protocol and using a hash ...
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2answers
235 views
Schnorr's identication protocol
Schnorr's identification protocol is said to be a honest verifier zero knowledge protocol. Does it imply it will not work if the verifier is dishonest?
I'm wondering if this is the case, it would ...
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1answer
468 views
Schnorr Identification protocol sometimes wrong?
I'm implementing the Schnorr Identification protocol as part of a larger protocol. In a large percentage of cases, around 20%, my test fails. I don't think it's a code problem, although possible, but ...
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1answer
914 views
Schnorr Identification Scheme under active adversary
According to the paper “GQ and Schnorr Identification Schemes: Proofs of Security against Impersonation under Active and Concurrent Attacks” by Mihir Bellare and Adriana Palacio, the Schnorr ...
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4answers
580 views
How to forge Schnorr signatures if you can guess the challenge
Underlying the Schnorr signature is an identification protocol: let $G$ be a cyclic group where discrete log is "hard" and choose $g$ as a generator of $G$. Now have Alice pick a random (secret) ...
