The most famous key exchange algorithm with perfect forward-secrecy.
7
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3answers
2k views
Can one generalize the Diffie-Hellman key exchange to three or more parties?
Does anyone know how to do a Diffie-Hellman or ECDH key exchange with more than two parties?
I know how to do a key exchange between 2 parties, but I need to be able to have a key agreement between 3 ...
5
votes
2answers
203 views
Besides key and ciphertext sizes what are other advantages of elliptic curve versions of various protocols?
There are elliptic curve variants of Diffie-Hellman, ElGamal, DSA and possibly other protocols/algorithms. I know that these elliptic curve variants have smaller key and ciphertext sizes which will ...
7
votes
7answers
3k views
Is Diffie-Hellman mathematically the same as RSA?
Is the Diffie-Hellman key exchange the same as RSA?
Diffie Hellman allows key exchange on a observed wire – but so can RSA.
Alice and Bob want to exchange a key – Big brother is watching everything.
...
20
votes
1answer
1k views
Does the generator size matter in Diffie-Hellman?
For the Diffie-Hellman protocol I've heard that the generator 3 is as safe as any other generator. Yet, 32-bit or 256-bit exponents are sometimes used as generators. What is the benefit of using ...
6
votes
2answers
2k views
What's the fundamental difference between Diffie-Hellman and RSA?
What is the difference in the purpose of DH and RSA? Aren't they both public-key encryption?
11
votes
3answers
1k views
For Diffie-Hellman, must g be a generator?
Due to a number of recently asked questions about Diffie-Hellman, I was thinking this morning: must $g$ in Diffie-Hellman be a generator?
Recall the mathematics of Diffie-Hellman:
Given public ...
0
votes
1answer
272 views
How do I generate a session key using the Diffie Hellman algorithm?
How to generate a session key between two nodes in two different subnets when the nodes don't know each other directly, using diffie hellman algorithm?
7
votes
2answers
314 views
Using same keypair for Diffie-Hellman and signing
Are there any security risks using a single key-pair for both key-exchange and signing?
I'm mainly interested in using Curve25519 for key-exchange and Ed25519 for signing. But similar combinations, ...
0
votes
1answer
155 views
How can the Diffie-Hellman key exchange be extended to three parties? [duplicate]
Possible Duplicate:
Can one generalize the Diffie-Hellman key exchange to three or more parties?
How can Alice, Bob, and Charlie share a common secret key using an extended version of the ...
5
votes
2answers
169 views
Which risks are associated with deriving multiple keys from the same DH secret Z?
NIST recommends Krawczyk's HMAC-based key derivation function (HKDF) in SP-800-56C (PDF). HKDF shall e.g. be used to create keys from shared secrets after Diffie Hellman key establishment.
NIST ...
3
votes
3answers
405 views
What is the relation between Discrete Log, Computational Diffie-Hellman and Decisional Diffie-Hellman?
How are the three problems Discrete Logarithm, Computational Diffie-Hellman and Decisional Diffie-Hellman related?
From my understanding, since the Discrete Log (DL) Problem is considered hard, then ...
1
vote
1answer
92 views
How large should a Diffie-Hellman p be if the messages are encrypted?
How large should the prime $p$ and generator $g$ values be in a Diffie-Hellman handshake if the messages are encrypted.
If the key that encrypted the Diffie-Hellman messages becomes compromised, ...
