Diffie hellman key agreement protocol

Who are those individuals?

Diffie and Hellman are researchers. These people invented the algorithm of “Diffie-Hellman key exchange” in the area of cryptography.

What they have got done?

They published the primary public-key algorithm known as the “Diffie-Hellman key exchange” precisely the same year, finally making exchange from the keys real and secure.

Overview with the Algorithm

Diffie-Hellman key exchange (D-H) is really a cryptographic that permits two parties that contain no prior knowledge of each other to jointly set up a shared secret key over an insecure communication channel. This key will then be used to encrypt subsequent communications having a symmetric key cipher.

Synonyms of Diffie-Hellman key exchange include:

o Key agreement

o Key establishment

o Key negotiation

o Exponential key exchange

o Diffie-Hellman protocol

The agreement was invented in 1976 during collaboration between Whitfield Diffie and Martin Hellman and was the 1st practical way for establishing a shared secret over an unprotected communication channel.

The method was followed shortly afterwards by RSA, another implementation of public key cryptography using asymmetric algorithms.

Protocol in action

The protocol has two system parameters p and g. They are both public and might be used by all of the users inside a system. Parameter p can be a prime number and parameter g (usually referred to as a generator) is definitely an integer under p, with all the following property: for each number n between 1 and p-1 inclusive, there is really a power k of g to ensure that n = gk mod p.

To create a simpler description we shall imagine 2 different people – Alice and Bob who would like to securely exchange data.

Suppose Alice and Bob would like to agree on a shared secret key with all the Diffie-Hellman key agreement protocol. They proceed as follows:

o Alice and Bob acknowledge a finite cyclic group G and also a generating element g in G. (This is usually done a long time before the rest from the protocol; g is assumed being known by all attackers).

o First, Alice generates a random private value a, and Bob generates a random private value b. Both a and b are sucked from the pair of integers.

o Then they derive their public values using parameters p and g in addition to their private values.

o Alice’s public value is ga mod p and Bob’s public value is gb mod p. They then exchange their public values.

o Finally, Alice computes gab = (gb) a mod p, and Bob computes gba = (ga) b mod p. Since gab = gba = k, Alice and Bob now take over a shared secret key k.

The important point could be that the two values generated are indifferent. They are the “Shared Secret” that may encrypt information between systems.

Leave a Reply

Your email address will not be published. Required fields are marked *