Error unexpected token when using crypto-js with angular 5 project

I need to encrypt data sent from angular-5 to php script and decrypt it in php then process it. I am new to these stuff.

Firstly, I installed the crypto-js lib:

npm install --save crypto-js

Then I imported it into app.module.ts:

import * as crypto from 'crypto-js';

And added it to imports:

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    crypto

Inside my app.component.ts file I am trying to encrypt a variable and test the result:

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'app';
  this.crypto...
}

I've got an error on the this.:

Unexpected token. A constructor, method, accessor, or property was expected.