The most famous key exchange algorithm with perfect forward-secrecy.
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3answers
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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 ...
4
votes
2answers
763 views
How to calculate the time it'll take to crack RSA or DH?
Sometimes the easiest way to describe security of a type of cryptography is to say that "the time it takes to solve for an x-bit key would be y years". How would one go about doing such a calculation ...
5
votes
2answers
815 views
Why can't Diffie-Hellman be used for signing?
I understand that signing is often a case of hashing data and then encrypting the hash with the private key. What properties keep Diffie-Hellman from being useful for this?
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3answers
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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 ...
7
votes
3answers
3k views
How does one calculate a primitive root for Diffie-Hellman?
In the Diffie-Hellman key exchange, one of the steps involves calculating a primitive root of a prime number $p$. How would one go about doing so, considering that $p$ could be very large?
Is there ...
7
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7answers
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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.
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20
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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 ...
