Biometric Authentication In iPhone Apps

Step-by-Step Guide To Integrate Biometric Authentication In iPhone Apps

By Harikrishna Kundariya iOS, Mobile March 26, 2020 7 min read 213 Views

Security has always been the number one priority. Be it banking, online trading, or any financial transaction; it becomes necessary to secure the platform that contains sensitive data or information.

This article will focus on security measures taken by iOS for its users. Along with the measures, you can also have a look at what security issues you might have to deal with while creating an application.

iOS always comes up with something innovative and fascinating. iPhone XR and iPhone XS have introduced biometric security measures, which includes, face & fingerprint recognition.

The demand for biometric security is increasing, and as per the market trends, there will be a drastic growth in biometric investments by 2027. As per the report, approximately $55Bn market value is predicted for biometric authentication.

There are 6 types of biometric authentications which are as follows:

  • Face Recognition
  • Iris Recognition
  • Fingerprint/Palm Recognition
  • Finger Vein Recognition
  • Voice Recognition
  • Ear Acoustic Recognition

Integrating Biometric Authentication in iPhone Apps is the best way to secure the device and data. It ensures the safety of vital information in the device.

The article will state how you can integrate biometric authentication in iPhone Apps with Touch ID:

Step 1: Initiate New Project

If you want to integrate biometric authentication in the iPhone app, then you have to follow the steps under Xcode, which are as follows:

  • Create a new project under the file menu
  • Select a Single View Application
  • After this, click on the Next button.

The interface would look something like the below image:


Step 2: Give a Name to the Project

You have to give a name to your project. You can give any name you like. After naming the project, you have to import the LocalAuthentication in Viewcontroller.swift.

Mobile app development services

Step 3: Add Privacy

Info.plist is where the faceID privacy statement needs to be configured. You might have seen the permission access request message before installing any application; it is the same privacy statement.

Biometric authentication in the iPhone App requires this statement to be approved. And to add the statement, you have to select the Info.plist file in the project manager panel, then click on the “+” button. You can find the button at the end of the list entry.

Now, you have to choose the Privacy-FaceID Usage Description from your preferred outcome of the previous program. Once you select, you can add the usage description to your preferred outcome. Below is the figure that will help you understand the process:


Step 4: Verify the availability of Biometric Authentication

One of the important steps is to verify the biometric authentication availability, and once you verify, you need to integrate it in the iPhone Apps. The code should be added in the authenticateUser method, which will ensure that the device can handle authentication.

You have to add code to the authenticateUser method by choosing ViewController.swift file and import the LocalAuthentication Framework. The code is as follows:

import UIKit

import LocalAuthentication

class ViewController: UIViewController {

    override func viewDidLoad() {


        // Do any additional setup after loading the view, typically from a nib.


    @IBAction func authenticateUser(_ sender: Any) {

        let context = LAContext()    

        var error: NSError?        

        if context.canEvaluatePolicy(


            error: &error) {                       

            // Device can use biometric authentication            

        } else {

            // Device cannot use biometric authentication

            if let err = error {

                switch err.code{                

                case LAError.Code.biometryNotEnrolled.rawValue:

                    notifyUser("User is not enrolled",

                           err: err.localizedDescription)                

                case LAError.Code.passcodeNotSet.rawValue:

                    notifyUser("A passcode has not been set",

                           err: err.localizedDescription)                                

                case LAError.Code.biometryNotAvailable.rawValue:

                    notifyUser("Biometric authentication not available",

                           err: err.localizedDescription)


                    notifyUser("Unknown error",

                           err: err.localizedDescription)





With the help of the above code, you can identify Touch ID or Face ID authentication on iOS devices. 

Step 5: Biometric Accessibility

Integrating the biometric authentication in iPhone apps requires availability, and if you find that the device supports biometric authentication, then you can plan to implement Face ID or Touch ID. The point mentioned above includes coding, which will help in verifying the accessibility.

Read also: Top Features of iOS 12 That App Developers Should Have Knowledge Of

Step 6: Looking For Biometric Authentication

After receiving the confirmation that biometric integration is possible in an iOS device, you have to follow the below command: 

@IBAction func authenticateUser(_ sender: Any) {

// Device can use biometric authentication

     if context.canEvaluatePolicy(


        error: &error) {



         localizedReason: self.strAlertMessage,

         reply: { [unowned self] (success, error) -> Void in

           DispatchQueue.main.async {

             if( success ) {

               //Fingerprint recognized

               // Do whatever action you want to perform

             } else {

                //If not recognized then

                if let error = error {

                   let strMessage = self.errorMessage(errorCode: error._code)








Step 7: Challenges During Integration

If you are a developer and would want to be ready for the errors proactively, then the below code might help you. The error code may look like this:

// MARK: Get error message

func errorMessage(errorCode:Int) -> String{

    var strMessage = "" 

    switch errorCode {

    case LAError.authenticationFailed.rawValue:

      strMessage = "Authentication Failed" 

    case LAError.userCancel.rawValue:

      strMessage = "User Cancel" 

    case LAError.userFallback.rawValue:

      strMessage = "User Fallback" 

    case LAError.systemCancel.rawValue:

      strMessage = "System Cancel" 

    case LAError.passcodeNotSet.rawValue:

      strMessage = "Passcode Not Set"

    case LAError.biometryNotAvailable.rawValue:

      strMessage = "TouchI DNot Available" 

    case LAError.biometryNotEnrolled.rawValue:

      strMessage = "TouchID Not Enrolled" 

    case LAError.biometryLockout.rawValue:

      strMessage = "TouchID Lockout" 

    case LAError.appCancel.rawValue:

      strMessage = "App Cancel" 

    case LAError.invalidContext.rawValue:

      strMessage = "Invalid Context" 


      strMessage = "Some error found"


    return strMessage 


So, now you know how to integrate biometric authentication into iPhone apps. Let’s see how Face ID can be implemented in your iOS device.

Procedure to add the Face ID privacy statement

You have to test the biometric authentication before implementing it to the iOS device. There are two methods; first, an iOS device to support biometric authentication and second, employ a simulator environment.

A point to note for the developers who are planning to opt for employing a simulator environment; it becomes important for compilation and running the app on iPhone X.

The release of the iOS app demands to select the simulator’s hardware after selecting the Face ID menu. In addition, you should enable the enrolled option, as shown in the below image.

Face ID menu

Once the test is completed, the application will ask for permission to allow the easy integration of biometric authentication to the iPhone application. The below image shows the message and the pop-up that comes on the screen.

message and the pop-upfor iphone apps

The successful permitting will redirect you to the home screen where there will be an Authenticate button with fingerprint icon and Face ID.

As shown in the below image, you will come across a gray simulated Face ID panel:

Biometric Authentication Face ID

For Touch ID, there will be a pop-up on the screen wherein it will ask to integrate fingerprint to secure the app. After confirming, the page will redirect you to the successful authentication screen.

This way, you can integrate biometric authentication into iOS applications successfully. With this, there is also a history of Face ID and Touch ID attached in the form of an image which might help you understand biometric authentication.

biometric authentication


Security is essential for applications as it contains vital information just like your hard files do. But, implementing biometrics authentication in iPhone Apps was something that has fascinated the iPhone users.

If you, as an app owner, want to integrate biometric authentication in iPhone apps, then you can hire iOS developers who have hands-on experience in executing quality tasks.

Hire mobile app developers


Biometric authentication is computer science, which ensures identification and access control. It has numerous benefits, such as security, scalable, efficiency, precise identification, and many more things.

It is the process of verifying the user’s identity by scanning some part of their body, and then allowing access to the application, device, or service. You can integrate finger, eye, or face recognition to your device and secure your app.

Iris recognition turns out to be the best biometric authentication integration in your iPhone apps. It scans your iris and provides access to your device.

The characteristics of biometric identification include facial recognition, voice recognition, and analysis of DNA.

Biometric Authentication In iPhone Apps

Disclaimer: We at eSparkBiz Technologies have created this blog with all the consideration and utmost care. We always strive for excellence in each of our blog posts and for that purpose, we ensure that all the information written in the blog is complete, correct, comprehensible, accurate and up-to-date. However, we can’t always guarantee that the information written in the blog correct, accurate or up-to-date. Therefore, we always advise our valuable readers not to take any kind of decisions based on the information as well as the views shared by our authors. The readers should always conduct an in-depth research before making the final decision. In addition to these, all the logos, 3rd part trademarks and screenshots of websites & mobile apps are the property of the individual owners. We’re not associated with any of them.

Harikrishna Kundariya

Harikrishna Kundariya

Harikrishna Kundariya, a marketer, developer, app lover, technology savvy, designer, co-founder, Director of eSparkBiz @Mobile App Development Company where you can Hire Mobile App Developer. His 8+ experience enables him to provide digital solutions to new start-ups based on app development.


Follow us

Subscribe Newsletter

Call us Today


Got any Questions?
call us Today!

+1 408 850 1488 [email protected]

Our Guides

Related Post

Top 13 Artificial Intelligence (AI) Apps For Android

Top 13 Artificial Intelligence (AI) Apps For Android

Mobile applications have laid the cornerstone in the industry, and the advancement of technology along with science has graveled the road for artificial intelligence apps.…

Exploring Swift Design Patterns For iOS App Development

Exploring Swift Design Patterns For iOS App Development

Swift was introduced in 2014, and within a short period, it has become popular in the field of iOS app development. It can build applications…

1 Share
In-Depth Guide To Develop Currency Converter App

In-Depth Guide To Develop Currency Converter App

You must have heard about the heavy economic terms - Globalization, Privatisation, and Liberation. Well, these terms have their meaning, which requires a deep study.…

Share via
Copy link