Questions tagged [diffie-hellman]
The Diffie–Hellman key agreement is an anonymous, non-authenticated key-agreement protocol.
157 questions with no upvoted or accepted answers
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The backdoor of Telegram on Diffie-Hellman Key Exchange and possibly other examples?
Diffie-Hellman Key-Exchange (DHKE) should be used carefully during the end-to-end encryption. A man-in-the-middle (MITM) attack is possible.
Standard DHKE
The simple protocol on the multiplicative ...
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How many qubits are required to break classical Diffie-Hellman?
There have been comparisons between RSA and ECDH with regards to the number of qubits required to break the algorithm with a specific key size. But how many qubits are required to break "...
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About a SETUP mechanism on ECDH
I'm following these three articles:
Kleptography: Using Cryptography Against Cryptography,
Kleptographic Attack on Elliptic Curve Based
Cryptographic Protocols and
Elliptic Curve Kleptography .
In ...
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Regarding the need to hash the shared secret in X25519 with the public keys
I was looking at the LibSodium documentation where it says
[...] and to mitigate subtle attacks due to the fact many $(p, n)$ [public key - secret scalar] pairs produce the same result, using the ...
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Precomputation attacks against ECDH
Diffie-Hellman groups are vulnerable to sieving precomputation attacks. These attacks allow a one-time computation against a given DH modulus that makes it practical to attack all subsequent key ...
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Are all MNT curves assumed to hold XDH?
For one of my projects, I need a pairing group which holds the External co-Diffie-Hellman assumption. I am trying to implement it using Charm crypto python modules which provides support for MNT ...
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How does post quantum key exchange in OpenSSH 8 work?
OpenSSH 8 supports a post quantum KEX, namely [email protected]
It says in its description that it is basically NTRU + ECC X25519. However, I have tried but cannot understand how ...
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Is it possible to create a useful hyperelliptic curve cover having Genus 2 for altbn254 or bls12-381?
I m looking for a way to perform pairings without final exponentiation or where the last step is easy to inverse (in order to perform pairing inversion through Miller inversion using https://eprint....
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Are there any projects leveraging a combination of (1) Noise and (2) Signal / Double Ratchet to augment the former with per-message forward secrecy?
Are there examples (in code, or a blog post / writeup) of using Noise and Signal together?
Here is a link to Noise.
For example, using the Double Ratchet per each message to achieve forward secrecy, ...
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Where do the PKs come from in Bluetooth device?
I am studying the Elliptic Curve Diffie-Hellman (ECDH) on Bluetooth 4.2.
There are some questions about the PK..
Where do these public and private keys come from?
Who defines them?
and Will it be ...
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Encrypt using ECDH with two different EC public keys, minimizing payload size
Let's say Alice has the private EC keys $a$ and $b$, with a base point of prime order $G$. Alice computes the corresponding public keys $A = aG$ and $B = bG$, and sends them to Bob.
Bob now wants to ...
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How to modify the Socialist Millionaire Protocol to be symmetric.
In the Socialist Millionaire Protocol, the roles of Alice and Bob are almost symmetric. By this I mean they do almost the same thing, until the very last step.
In the final step, both parties check a ...
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Compute key size in Hyperelliptic Curve Cryptography
I am trying to implement a basic Diffie-Hellman key exchange using ECC and HECC of genus 2 and 3 and compare them. However, I am a bit confused about the concept of key size in HECC.
In ECC, from my ...
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A tensor-based Diffie-Hellman exchange
Below is a description of a "cube" Diffie-Hellman, based on commuting matrix actions on tensor products. Some questions:
References for something similar?
Obvious flaws, is this a terrible ...
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Solving DDH from an ElGamal adversary
Suppose an adversary wins IND-CPA against ElGamal,
They're given public key $h=g^x$,
Give a pair of messages $m = [m0,m1]$,
Get back ciphertext $(a,b) = (g^r, g^{xr} \cdot g^{m[b]})$,
from which ...
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