diff --git a/src/core/operations/DeriveEVPKey.mjs b/src/core/operations/DeriveEVPKey.mjs
deleted file mode 100644
index b729d6ea..00000000
--- a/src/core/operations/DeriveEVPKey.mjs
+++ /dev/null
@@ -1,145 +0,0 @@
-/**
- * @author n1474335 [n1474335@gmail.com]
- * @copyright Crown Copyright 2016
- * @license Apache-2.0
- */
-
-import Operation from "../Operation.mjs";
-import Utils from "../Utils.mjs";
-import CryptoJS from "crypto-js";
-
-/**
- * Derive EVP key operation
- */
-class DeriveEVPKey extends Operation {
-
-    /**
-     * DeriveEVPKey constructor
-     */
-    constructor() {
-        super();
-
-        this.name = "Derive EVP key";
-        this.module = "Ciphers";
-        this.description = "This operation performs a password-based key derivation function (PBKDF) used extensively in OpenSSL. In many applications of cryptography, user security is ultimately dependent on a password, and because a password usually can't be used directly as a cryptographic key, some processing is required.<br><br>A salt provides a large set of keys for any given password, and an iteration count increases the cost of producing keys from a password, thereby also increasing the difficulty of attack.<br><br>If you leave the salt argument empty, a random salt will be generated.";
-        this.infoURL = "https://wikipedia.org/wiki/Key_derivation_function";
-        this.inputType = "string";
-        this.outputType = "string";
-        this.args = [
-            {
-                "name": "Passphrase",
-                "type": "toggleString",
-                "value": "",
-                "toggleValues": ["UTF8", "Latin1", "Hex", "Base64"]
-            },
-            {
-                "name": "Key size",
-                "type": "number",
-                "value": 128
-            },
-            {
-                "name": "Iterations",
-                "type": "number",
-                "value": 1
-            },
-            {
-                "name": "Hashing function",
-                "type": "option",
-                "value": ["SHA1", "SHA256", "SHA384", "SHA512", "MD5"]
-            },
-            {
-                "name": "Salt",
-                "type": "toggleString",
-                "value": "",
-                "toggleValues": ["Hex", "UTF8", "Latin1", "Base64"]
-            }
-        ];
-    }
-
-    /**
-     * @param {string} input
-     * @param {Object[]} args
-     * @returns {string}
-     */
-    run(input, args) {
-        const passphrase = Utils.convertToByteString(args[0].string, args[0].option),
-            keySize = args[1] / 32,
-            iterations = args[2],
-            hasher = args[3],
-            salt = Utils.convertToByteString(args[4].string, args[4].option),
-            key = CryptoJS.EvpKDF(passphrase, salt, {
-                keySize: keySize,
-                hasher: CryptoJS.algo[hasher],
-                iterations: iterations,
-            });
-
-        return key.toString(CryptoJS.enc.Hex);
-    }
-
-}
-
-export default DeriveEVPKey;
-
-/**
- * Overwriting the CryptoJS OpenSSL key derivation function so that it is possible to not pass a
- * salt in.
-
- * @param {string} password - The password to derive from.
- * @param {number} keySize - The size in words of the key to generate.
- * @param {number} ivSize - The size in words of the IV to generate.
- * @param {WordArray|string} salt (Optional) A 64-bit salt to use. If omitted, a salt will be
- *                 generated randomly. If set to false, no salt will be added.
- *
- * @returns {CipherParams} A cipher params object with the key, IV, and salt.
- *
- * @static
- *
- * @example
- * // Randomly generates a salt
- * var derivedParams = CryptoJS.kdf.OpenSSL.execute('Password', 256/32, 128/32);
- * // Uses the salt 'saltsalt'
- * var derivedParams = CryptoJS.kdf.OpenSSL.execute('Password', 256/32, 128/32, 'saltsalt');
- * // Does not use a salt
- * var derivedParams = CryptoJS.kdf.OpenSSL.execute('Password', 256/32, 128/32, false);
- */
-CryptoJS.kdf.OpenSSL.execute = function (password, keySize, ivSize, salt) {
-    // Generate random salt if no salt specified and not set to false
-    // This line changed from `if (!salt) {` to the following
-    if (salt === undefined || salt === null) {
-        salt = CryptoJS.lib.WordArray.random(64/8);
-    }
-
-    // Derive key and IV
-    const key = CryptoJS.algo.EvpKDF.create({ keySize: keySize + ivSize }).compute(password, salt);
-
-    // Separate key and IV
-    const iv = CryptoJS.lib.WordArray.create(key.words.slice(keySize), ivSize * 4);
-    key.sigBytes = keySize * 4;
-
-    // Return params
-    return CryptoJS.lib.CipherParams.create({ key: key, iv: iv, salt: salt });
-};
-
-
-/**
- * Override for the CryptoJS Hex encoding parser to remove whitespace before attempting to parse
- * the hex string.
- *
- * @param {string} hexStr
- * @returns {CryptoJS.lib.WordArray}
- */
-CryptoJS.enc.Hex.parse = function (hexStr) {
-    // Remove whitespace
-    hexStr = hexStr.replace(/\s/g, "");
-
-    // Shortcut
-    const hexStrLength = hexStr.length;
-
-    // Convert
-    const words = [];
-    for (let i = 0; i < hexStrLength; i += 2) {
-        words[i >>> 3] |= parseInt(hexStr.substr(i, 2), 16) << (24 - (i % 8) * 4);
-    }
-
-    return new CryptoJS.lib.WordArray.init(words, hexStrLength / 2);
-};