Diffie – Hellman key exchange ( D – H ) is a specific method of exchanging cryptographic keys.

The Diffie – Hellman key exchange method allows two parties that have no prior knowledge of each other to jointly establish a shared secret key over an insecure communications channel.

In 2002, Hellman suggested the algorithm be called Diffie – Hellman – Merkle key exchange in recognition of Ralph Merkle's contribution to the invention of public-key cryptography ( Hellman, 2002 ).

Although Diffie – Hellman key agreement itself is an anonymous ( non-authenticated ) key-agreement protocol, it provides the basis for a variety of authenticated protocols, and is used to provide perfect forward secrecy in Transport Layer Security's ephemeral modes ( referred to as EDH or DHE depending on the cipher suite ).

The system ... has since become known as Diffie – Hellman key exchange.

While that system was first described in a paper by Diffie and me, it is a public key distribution system, a concept developed by Merkle, and hence should be called ' Diffie – Hellman – Merkle key exchange ' if names are to be associated with it.

Diffie – Hellman establishes a shared secret that can be used for secret communications by exchanging data over a public network.

* the elliptic curve Diffie – Hellman ( ECDH ) key agreement scheme is based on the Diffie – Hellman scheme,

* Curve25519: A state-of-the-art Diffie – Hellman function by Dan Bernstein

Several public-key cryptography algorithms, such as RSA and the Diffie – Hellman key exchange, are based on large prime numbers ( for example 512 bit primes are frequently used for RSA and 1024 bit primes are typical for Diffie – Hellman .).

The Diffie – Hellman key exchange relies on the fact that there are efficient algorithms for modular exponentiation, while the reverse operation the discrete logarithm is thought to be a hard problem.

Diffie – Hellman key exchange is the most widely used public key distribution system, while the Digital Signature Algorithm is the most widely used digital signature system.

These researchers independently developed Diffie – Hellman key exchange, and a special case of RSA.

The scheme was first published by Whitfield Diffie and Martin Hellman in 1976, although it was later alleged that it had been separately invented a few years earlier within GCHQ, the British signals intelligence agency, by Malcolm J. Williamson but was kept classified.

, now expired, describes the algorithm and credits Hellman, Diffie, and Merkle as inventors.

There was some criticism from various parties, including from public-key cryptography pioneers Martin Hellman and Whitfield Diffie, citing a shortened key length and the mysterious " S-boxes " as evidence of improper interference from the NSA.

This method of key exchange, which uses exponentiation in a finite field, came to be known as Diffie – Hellman key exchange.

* Diffie – Hellman key exchange protocol

It was the need to synchronize the scramblers that suggested to James H. Ellis the idea for non-secret encryption which ultimately led to the invention of both the RSA encryption algorithm and Diffie-Hellman key exchange well before either was reinvented publicly by Rivest, Shamir, and Adleman, or by Diffie and Hellman.

In cryptography, the ElGamal encryption system is an asymmetric key encryption algorithm for public-key cryptography which is based on the Diffie – Hellman key exchange.

The public disclosure of both secure key exchange and asymmetric key algorithms in 1976 by Diffie, Hellman, Rivest, Shamir, and Adleman changed secure communications entirely.

IKE uses X. 509 certificates for authentication which are either pre-shared or distributed using DNS ( preferably with DNSSEC ), and a Diffie – Hellman key exchange to set up a shared session secret from which cryptographic keys are derived.

IKE phase 1's purpose is to establish a secure authenticated communication channel by using the Diffie – Hellman key exchange algorithm to generate a shared secret key to encrypt further IKE communications.

Diffie – Hellman key exchange •

# REDIRECT Diffie – Hellman key exchange

# REDIRECT Diffie – Hellman key exchange

It has become known as Diffie – Hellman key exchange.

It has become known as Diffie – Hellman key exchange.

In 1976, Whitfield Diffie and Martin Hellman first described the notion of a digital signature scheme, although they only conjectured that such schemes existed.

Diffie and Hellman, however, devised a time-memory tradeoff that could break the scheme in only double the time to break the single-encryption scheme.

MQV ( Menezes – Qu – Vanstone ) is an authenticated protocol for key agreement based on the Diffie – Hellman scheme.

Also, the confidentiality of ElGamal encryption is equivalent to the CDH assumption ( though the semantic security of the scheme is based on the decisional Diffie – Hellman assumption ).

Leading cryptography scholar Martin Hellman discusses the circumstances and fundamental insights of his invention of public key cryptography with collaborators Whitfield Diffie and Ralph Merkle at Stanford University in the mid-1970s.

Hellman describes his invention of public key cryptography with collaborators Whitfield Diffie and Ralph Merkle at Stanford University in the mid-1970s.

Trapdoor functions came to prominence in cryptography in the mid-1970s with the publication of asymmetric ( or public key ) encryption techniques by Diffie, Hellman, and Merkle.

Hellman describes his invention of public key cryptography with collaborators Whitfield Diffie and Ralph Merkle at Stanford University in the mid-1970s.

Hellman describes his invention of public key cryptography with collaborators Whitfield Diffie and Ralph Merkle at Stanford University in the mid-1970s.

Martin Edward Hellman ( born October 2, 1945 ) is an American cryptologist, and is best known for his invention of public key cryptography in cooperation with Whitfield Diffie and Ralph Merkle.

Hellman describes his invention of public key cryptography with collaborators Whitfield Diffie and Ralph Merkle at Stanford University in the mid-1970s.

However, the discrete logarithm problem can be used as the basis for a trapdoor when the related problems called the computational Diffie – Hellman problem ( CDH ) and / or its decisional variant are used.

As he did with the new cuts for his Greatest Hits package, Diffie worked with producer Don Cook and producer / session drummer Lonnie Wilson, a friend of Diffie's who formerly fronted the band Bandana.