diff --git a/SMLoadr.js b/SMLoadr.js
index 3d0b00b..249cdab 100644
--- a/SMLoadr.js
+++ b/SMLoadr.js
@@ -20,7 +20,6 @@ require('./node_modules/cache-manager/lib/stores/memory');
 const requestPlus = require('request-plus');
 const id3Writer = require('./libs/browser-id3-writer');
 const flacMetadata = require('./libs/flac-metadata');
-const crypto = require('crypto');
 const inquirer = require('inquirer');
 const fs = require('fs');
 const stream = require('stream');
@@ -37,6 +36,9 @@ const configFile = 'SMLoadrConfig.json';
 const ConfigService = require('./src/service/ConfigService');
 let configService = new ConfigService(configFile);
 
+const EncryptionService = require('./src/service/EncryptionService');
+let encryptionService = new EncryptionService();
+
 const Log = require('log');
 
 let DOWNLOAD_DIR = 'DOWNLOADS/';
@@ -1973,15 +1975,9 @@ function sanitizeFilename(fileName) {
  * @returns {String}
  */
 function getTrackDownloadUrl(trackInfos, trackQuality) {
-    const step1 = [trackInfos.MD5_ORIGIN, trackQuality, trackInfos.SNG_ID, trackInfos.MEDIA_VERSION].join('¤');
-
-    let step2 = crypto.createHash('md5').update(step1, 'ascii').digest('hex') + '¤' + step1 + '¤';
-    while (step2.length % 16 > 0) step2 += ' ';
-
-    const step3 = crypto.createCipheriv('aes-128-ecb', 'jo6aey6haid2Teih', '').update(step2, 'ascii', 'hex');
     const cdn = trackInfos.MD5_ORIGIN[0];
 
-    return 'https://e-cdns-proxy-' + cdn + '.dzcdn.net/mobile/1/' + step3;
+    return 'https://e-cdns-proxy-' + cdn + '.dzcdn.net/mobile/1/' + encryptionService.getSongFileName(trackInfos, trackQuality);
 }
 
 /**
@@ -2072,62 +2068,6 @@ function getValidTrackQuality(trackInfos) {
     return false;
 }
 
-/**
- * Calculate the blowfish key to decrypt the track
- *
- * @param {Object} trackInfos
- */
-function getBlowfishKey(trackInfos) {
-    const SECRET = 'g4el58wc0zvf9na1';
-
-    const idMd5 = crypto.createHash('md5').update(trackInfos.SNG_ID.toString(), 'ascii').digest('hex');
-    let bfKey = '';
-
-    for (let i = 0; i < 16; i++) {
-        bfKey += String.fromCharCode(idMd5.charCodeAt(i) ^ idMd5.charCodeAt(i + 16) ^ SECRET.charCodeAt(i));
-    }
-
-    return bfKey;
-}
-
-/**
- * Decrypt a deezer track.
- *
- * @param {Buffer} trackBuffer
- * @param {Object} trackInfos
- *
- * @return {Buffer}
- */
-function decryptTrack(trackBuffer, trackInfos) {
-    const blowFishKey = getBlowfishKey(trackInfos);
-
-    let decryptedBuffer = Buffer.alloc(trackBuffer.length);
-    let chunkSize = 2048;
-    let progress = 0;
-
-    while (progress < trackBuffer.length) {
-        if ((trackBuffer.length - progress) < 2048) {
-            chunkSize = trackBuffer.length - progress;
-        }
-
-        let encryptedChunk = trackBuffer.slice(progress, progress + chunkSize);
-
-        // Only decrypt every third chunk and only if not at the end
-        if (progress % (chunkSize * 3) === 0 && chunkSize === 2048) {
-            let cipher = crypto.createDecipheriv('bf-cbc', blowFishKey, Buffer.from([0, 1, 2, 3, 4, 5, 6, 7]));
-            cipher.setAutoPadding(false);
-
-            encryptedChunk = Buffer.concat([cipher.update(encryptedChunk), cipher.final()]);
-        }
-
-        decryptedBuffer.write(encryptedChunk.toString('binary'), progress, encryptedChunk.length, 'binary');
-
-        progress += chunkSize;
-    }
-
-    return decryptedBuffer;
-}
-
 /**
  * Download the track, decrypt it and write it to a file.
  *
@@ -2150,7 +2090,7 @@ function downloadTrack(trackInfos, trackQualityId, saveFilePath, numberRetry = 0
         }).then((response) => {
             log.debug('Got download response for "track/' + trackInfos.SNG_ID + '"');
 
-            const decryptedTrackBuffer = decryptTrack(response, trackInfos);
+            const decryptedTrackBuffer = encryptionService.decryptTrack(response, trackInfos);
 
             resolve(decryptedTrackBuffer);
         }).catch((err) => {
diff --git a/src/service/EncryptionService.js b/src/service/EncryptionService.js
new file mode 100644
index 0000000..0f02408
--- /dev/null
+++ b/src/service/EncryptionService.js
@@ -0,0 +1,70 @@
+const crypto = require('crypto');
+
+module.exports = class EncryptionService {
+
+    getSongFileName(trackInfos, trackQuality) {
+        const step1 = [trackInfos.MD5_ORIGIN, trackQuality, trackInfos.SNG_ID, trackInfos.MEDIA_VERSION].join('¤');
+
+        let step2 = crypto.createHash('md5').update(step1, 'ascii').digest('hex') + '¤' + step1 + '¤';
+        while (step2.length % 16 > 0) step2 += ' ';
+
+        return crypto.createCipheriv('aes-128-ecb', 'jo6aey6haid2Teih', '').update(step2, 'ascii', 'hex');
+    }
+
+
+    /**
+     * Calculate the blowfish key to decrypt the track
+     *
+     * @param {Object} trackInfos
+     */
+    getBlowfishKey(trackInfos) {
+        const SECRET = 'g4el58wc0zvf9na1';
+
+        const idMd5 = crypto.createHash('md5').update(trackInfos.SNG_ID.toString(), 'ascii').digest('hex');
+        let bfKey = '';
+
+        for (let i = 0; i < 16; i++) {
+            bfKey += String.fromCharCode(idMd5.charCodeAt(i) ^ idMd5.charCodeAt(i + 16) ^ SECRET.charCodeAt(i));
+        }
+
+        return bfKey;
+    }
+
+    /**
+     * Decrypt a deezer track.
+     *
+     * @param {Buffer} trackBuffer
+     * @param {Object} trackInfos
+     *
+     * @return {Buffer}
+     */
+    decryptTrack(trackBuffer, trackInfos) {
+        const blowFishKey = this.getBlowfishKey(trackInfos);
+
+        let decryptedBuffer = Buffer.alloc(trackBuffer.length);
+        let chunkSize = 2048;
+        let progress = 0;
+
+        while (progress < trackBuffer.length) {
+            if ((trackBuffer.length - progress) < 2048) {
+                chunkSize = trackBuffer.length - progress;
+            }
+
+            let encryptedChunk = trackBuffer.slice(progress, progress + chunkSize);
+
+            // Only decrypt every third chunk and only if not at the end
+            if (progress % (chunkSize * 3) === 0 && chunkSize === 2048) {
+                let cipher = crypto.createDecipheriv('bf-cbc', blowFishKey, Buffer.from([0, 1, 2, 3, 4, 5, 6, 7]));
+                cipher.setAutoPadding(false);
+
+                encryptedChunk = Buffer.concat([cipher.update(encryptedChunk), cipher.final()]);
+            }
+
+            decryptedBuffer.write(encryptedChunk.toString('binary'), progress, encryptedChunk.length, 'binary');
+
+            progress += chunkSize;
+        }
+
+        return decryptedBuffer;
+    }
+};
\ No newline at end of file