Node.js crypto.createDiffieHellman(prime, primeEncoding, generator, generatorEncoding) Method
Last Updated :
28 Apr, 2025
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The crypto.createDiffieHellman() method is used to create a DiffieHellman key exchange object by using the stated prime and an optional specified generator.
Syntax:
crypto.createDiffieHellman( prime, primeEncoding,
generator, generatorEncoding )
Parameters: This method accept four parameters as mentioned above and described below:
- prime: It can hold string, Buffer, TypedArray, or DataView type of elements.
- primeEncoding: It is the encoding of the prime string and is of type string.
- generator: It can hold number, string, Buffer, TypedArray, or DataView type of data. Its default value is 2.
- generatorEncoding: It is the encoding of the generator string and returns string.
Return Value: It returns DiffieHellman key exchange object.
Below examples illustrate the use of crypto.createDiffieHellman() method in Node.js:
Example 1:
// Node.js program to demonstrate the
// crypto.createDiffieHellman() method
// Including crypto module
const crypto = require('crypto');
// Creating DiffieHellman with prime
const alice = crypto.createDiffieHellman(20);
// Generate keys
alice.generateKeys();
// Creating DiffieHellman to get
// prime and generator
const bob= crypto.createDiffieHellman(
alice.getPrime(), alice.getGenerator());
bob.generateKeys();
// Prints prime and generator for
// Alice with encoding
console.log("Alice prime (p):",
alice.getPrime().toString('hex'),
"\nAlice generator (G):",
alice.getGenerator().toString('hex')
);
Output:
Alice prime (p): 0a134b Alice generator (G): 02
Example 2:
// Node.js program to demonstrate the
// crypto.createDiffieHellman() method
// Including crypto module
const crypto = require('crypto');
// Creating DiffieHellman with prime
const k = crypto.createDiffieHellman(30);
// Accessing prime value
const p = k.getPrime();
// Accessing generator value
const g = k.getGenerator();
// Prints prime value
console.log(p);
// Prints generator value
console.log(g);
Output:
// Buffer 22 4a 58 5b // Buffer 02
Therefore, both prime and generator returns buffer.
Reference: https://nodejs.org/api/crypto.html#crypto_crypto_creatediffiehellman_prime_primeencoding_generator_generatorencoding
