Node.js crypto.createDecipheriv() Method

Last Updated : 28 Apr, 2025

The crypto.createDecipheriv() method is an inbuilt application programming interface of crypto module which is used to create a Decipher object, with the stated algorithm, key and initialization vector i.e, (iv).

Syntax:

crypto.createDecipheriv( algorithm, key, iv, options )

Parameters: This method accept four parameters as mentioned above and described below:

algorithm: It is a string type value that dependent on OpenSSL. The examples are aes192, aes256, etc.
key: It is the raw key which is used by the algorithm and iv. It holds the string, Buffer, TypedArray or DataView. The key can be a KeyObject optionally of type secret.
iv: It is an initialization vector that must be uncertain and very unique. However, an ideal iv will be cryptographically random. It don't need to be secret. It can holds string, Buffer, TypedArray, or DataView type data. If cipher doesn't requires iv then it can be null.
options: It is an optional parameter that is used to control stream behavior. It is optional except when a cipher is used in CCM or OCB mode(e.g. 'aes-128-ccm'). In that case, the authTagLength option is required which defines the length(bytes) of the authentication tag whereas, in GCM mode, the authTagLength option is not needed but it can be used to set the length of the authentication tag that will be returned by the getAuthTag() method and the default value is 16 bytes.

Return Value: It returns Decipher object.

Below examples illustrate the use of crypto.createDecipheriv() method in Node.js:

Example 1:

javascript

// Node.js program to demonstrate the      // crypto.createDecipheriv() method  // Includes crypto module const crypto = require('crypto');  // Defining algorithm const algorithm = 'aes-192-cbc';  // Defining password const password = 'bncaskdbvasbvlaslslasfhj';  // Defining key const key = crypto.scryptSync(password, 'GfG', 24);  // Defininf iv const iv = Buffer.alloc(16, 0);   // Creating decipher const decipher =      crypto.createDecipheriv(algorithm, key, iv);  // Declaring decrypted let decrypted = '';  // Reading data decipher.on('readable', () => {   let chunk;   while (null !== (chunk = decipher.read())) {     decrypted += chunk.toString('utf8');   } });  // Handling end event decipher.on('end', () => { console.log(decrypted); });  // Encrypted data which is to be decrypted const encrypted =   'MfHwhG/WPv+TIbG/qM78qA==';  decipher.write(encrypted, 'base64'); decipher.end();  console.log("done");

Output:

done CS-Portal

Example 2:

javascript

// Node.js program to demonstrate the      // crypto.createDecipheriv() method  // Includes crypto module const crypto = require('crypto');  // Defining algorithm const algorithm = 'aes-256-cbc';  // Defining key const key = crypto.randomBytes(32);  // Defining iv const iv = crypto.randomBytes(16);  // An encrypt function function encrypt(text) {   // Creating Cipheriv with its parameter  let cipher =      crypto.createCipheriv('aes-256-cbc', Buffer.from(key), iv);   // Updating text  let encrypted = cipher.update(text);   // Using concatenation  encrypted = Buffer.concat([encrypted, cipher.final()]);   // Returning iv and encrypted data  return { iv: iv.toString('hex'),      encryptedData: encrypted.toString('hex') }; }  // A decrypt function function decrypt(text) {   let iv = Buffer.from(text.iv, 'hex');  let encryptedText =     Buffer.from(text.encryptedData, 'hex');   // Creating Decipher  let decipher = crypto.createDecipheriv(         'aes-256-cbc', Buffer.from(key), iv);   // Updating encrypted text  let decrypted = decipher.update(encryptedText);  decrypted = Buffer.concat([decrypted, decipher.final()]);   // returns data after decryption  return decrypted.toString(); }  // Encrypts output var output = encrypt("GeeksforGeeks"); console.log(output);  // Decrypts output console.log(decrypt(output));

Output:

{ iv: '6bbc47a2756d6d6bf315cfd3cc0b711a',  encryptedData: 'fae9a6fb31c0b0668da8c3be1b1da81a' } GeeksforGeeks

Reference: https://nodejs.org/api/crypto.html#crypto_crypto_createdecipheriv_algorithm_key_iv_options

Node crypto.createCipheriv() Method

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Node.js crypto.createDecipheriv() Method

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