diff --git a/angular.json b/angular.json
index fbcae5a..9afefbb 100644
--- a/angular.json
+++ b/angular.json
@@ -23,6 +23,9 @@
             "polyfills": [
               "zone.js"
             ],
+            "allowedCommonJsDependencies": [
+              "crypto-js"
+            ],
             "tsConfig": "tsconfig.app.json",
             "inlineStyleLanguage": "sass",
             "assets": [
diff --git a/package-lock.json b/package-lock.json
index b1ba46a..5378f9a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -16,7 +16,9 @@
         "@angular/platform-browser": "^16.1.0",
         "@angular/platform-browser-dynamic": "^16.1.0",
         "@angular/router": "^16.1.0",
+        "@types/crypto-js": "^4.1.1",
         "angular-cli-ghpages": "^1.0.6",
+        "crypto-js": "^4.1.1",
         "rxjs": "~7.8.0",
         "tslib": "^2.3.0",
         "xp.css": "^0.2.6",
@@ -3242,6 +3244,11 @@
         "@types/node": "*"
       }
     },
+    "node_modules/@types/crypto-js": {
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/@types/crypto-js/-/crypto-js-4.1.1.tgz",
+      "integrity": "sha512-BG7fQKZ689HIoc5h+6D2Dgq1fABRa0RbBWKBd9SP/MVRVXROflpm5fhwyATX5duFmbStzyzyycPB8qUYKDH3NA=="
+    },
     "node_modules/@types/eslint": {
       "version": "8.44.1",
       "resolved": "https://registry.npmjs.org/@types/eslint/-/eslint-8.44.1.tgz",
@@ -3326,9 +3333,9 @@
       "dev": true
     },
     "node_modules/@types/node": {
-      "version": "20.4.6",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-20.4.6.tgz",
-      "integrity": "sha512-q0RkvNgMweWWIvSMDiXhflGUKMdIxBo2M2tYM/0kEGDueQByFzK4KZAgu5YHGFNxziTlppNpTIBcqHQAxlfHdA==",
+      "version": "20.4.8",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-20.4.8.tgz",
+      "integrity": "sha512-0mHckf6D2DiIAzh8fM8f3HQCvMKDpK94YQ0DSVkfWTG9BZleYIWudw9cJxX8oCk9bM+vAkDyujDV6dmKHbvQpg==",
       "dev": true
     },
     "node_modules/@types/qs": {
@@ -4892,6 +4899,11 @@
         "node": ">= 8"
       }
     },
+    "node_modules/crypto-js": {
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/crypto-js/-/crypto-js-4.1.1.tgz",
+      "integrity": "sha512-o2JlM7ydqd3Qk9CA0L4NL6mTzU2sdx96a+oOfPu8Mkl/PK51vSyoi8/rQ8NknZtk44vq15lmhAj9CIAGwgeWKw=="
+    },
     "node_modules/css-loader": {
       "version": "6.8.1",
       "resolved": "https://registry.npmjs.org/css-loader/-/css-loader-6.8.1.tgz",
diff --git a/package.json b/package.json
index c8cc89d..5e373fb 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,9 @@
     "@angular/platform-browser": "^16.1.0",
     "@angular/platform-browser-dynamic": "^16.1.0",
     "@angular/router": "^16.1.0",
+    "@types/crypto-js": "^4.1.1",
     "angular-cli-ghpages": "^1.0.6",
+    "crypto-js": "^4.1.1",
     "rxjs": "~7.8.0",
     "tslib": "^2.3.0",
     "xp.css": "^0.2.6",
diff --git a/src/app/correct-answer-window/correct-answer-window.component.ts b/src/app/correct-answer-window/correct-answer-window.component.ts
index 5dea2b6..6bf2bd6 100644
--- a/src/app/correct-answer-window/correct-answer-window.component.ts
+++ b/src/app/correct-answer-window/correct-answer-window.component.ts
@@ -32,7 +32,7 @@ export class CorrectAnswerWindowComponent implements OnInit {
 
   private saveCurrentScore(): void {
     const currentScore: string | null = this.storageService.get(StorageKeyEnum.CURRENT_SCORE);
-    let currentScoreNumber: number = currentScore === null ? 0 : parseInt(currentScore);
+    let currentScoreNumber: number = (currentScore === null || currentScore === '') ? 0 : parseInt(currentScore);
 
     currentScoreNumber += this.questionScore;
 
diff --git a/src/app/main-window/main-window.component.ts b/src/app/main-window/main-window.component.ts
index 350d63d..b0aff4f 100644
--- a/src/app/main-window/main-window.component.ts
+++ b/src/app/main-window/main-window.component.ts
@@ -61,7 +61,7 @@ export class MainWindowComponent implements OnInit {
 
         if (sameHour && sameMinute && sameSecond) {
           this.quizCanBeAnswered = true;
-          this.storageService.save(StorageKeyEnum.LAST_QUIZ_RESPONSE_DATE, '');
+          this.storageService.clear(StorageKeyEnum.LAST_QUIZ_RESPONSE_DATE);
           resolve();
           break;
         }
diff --git a/src/app/score-window/score-window.component.ts b/src/app/score-window/score-window.component.ts
index 4dd3ffd..e7dbc7e 100644
--- a/src/app/score-window/score-window.component.ts
+++ b/src/app/score-window/score-window.component.ts
@@ -21,7 +21,7 @@ export class ScoreWindowComponent implements OnInit {
   public ngOnInit(): void {
     const currentScore: string | null = this.storageService.get(StorageKeyEnum.CURRENT_SCORE);
 
-    this.score = currentScore === null ? 0 : parseInt(currentScore);
+    this.score = (currentScore === null || currentScore === '') ? 0 : parseInt(currentScore);
   }
 
   public async returnHome(): Promise<void> {
diff --git a/src/service/storage.service.ts b/src/service/storage.service.ts
index 31a9d6d..5d17ea1 100644
--- a/src/service/storage.service.ts
+++ b/src/service/storage.service.ts
@@ -1,5 +1,6 @@
 import {Injectable} from '@angular/core';
 import {StorageKeyEnum} from "../model/StorageKeyEnum";
+import { AES, enc } from 'crypto-js';
 
 @Injectable({
   providedIn: 'root'
@@ -7,16 +8,33 @@ import {StorageKeyEnum} from "../model/StorageKeyEnum";
 export class StorageService {
 
   private readonly localStorage: Storage;
+  private readonly KEY: string = 'ENCRYPTION_KEY';
 
   constructor() {
     this.localStorage = window.localStorage;
   }
 
   public save(key: StorageKeyEnum, value: string): void {
-    this.localStorage.setItem(key, value);
+    this.localStorage.setItem(key, this.encrypt(value));
   }
 
   public get(key: StorageKeyEnum): string | null {
-    return this.localStorage.getItem(key);
+    const encryptedItem: string | null = this.localStorage.getItem(key);
+
+    return encryptedItem === null ? '' : this.decrypt(encryptedItem);
+  }
+
+  public clear(key: StorageKeyEnum) {
+    this.localStorage.removeItem(key);
+  }
+
+  private encrypt(value: string): string {
+    const encrypted = AES.encrypt(value, this.KEY);
+    return encrypted.toString();
+  }
+
+  private decrypt(value: string): string {
+    const decrypted = AES.decrypt(value, this.KEY);
+    return decrypted.toString(enc.Utf8);
   }
 }