How to Use a Payload Signing Key with Mobile Bot Defense

Last updated November 7, 2024 by Appdome

Learn to Add Payload Signing Key in Mobile apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

What is a Payload Signing Key?

A Payload Signing Key is a crucial security component used within Appdome’s Mobile Bot Defense to ensure the integrity and confidentiality of session header payloads. Specifically, it leverages public key cryptography, where the public key, known as the Payload Signing Key, encrypts data that only the corresponding private key can decrypt.

How Does Appdome Protect Mobile Apps with the Payload Signing Key?

Appdome enhances the security of mobile applications by utilizing Payload Signing Keys within its Mobile Bot Defense framework. Each application is assigned a unique Payload Signing Key, ensuring that the encryption is tailored specifically to each app. This approach is crucial for safeguarding session header payloads, protecting sensitive data from interception or manipulation during data transmission. To accommodate configurations with multiple hosts, Appdome allows for the assignment of distinct Payload Signing Keys for each host, identified as payload key_0, key_1, key_2, etc. This setup ensures that a security breach in one application does not compromise any other, maintaining rigorous isolation and precision in encryption practices across the platform.

Understanding the Index for Payload Signing Keys

When adding a Payload Signing Key, it’s essential to understand how indexing works:

  • The first Payload Signing Key added under Session Headers is automatically assigned index 0. This key applies to the primary host profile by default.
  • For additional host profiles, each new Payload Signing Key is indexed incrementally as 1, 2, 3, etc. This indexing allows you to assign different keys to separate hosts.

To override the default key (index 0), use the following API format:

mobile_anti_bot_list {0}.value.payload_signing

Prerequisites for Using Payload Signing Key:

To use Appdome’s mobile app security build system to Add Payload Signing Key , you’ll need:

Add Payload Signing Key on Mobile apps using Appdome

On Appdome, follow these simple steps to create self-defending Mobile Apps that Add Payload Signing Key without an SDK or gateway:

  1. Upload the Mobile App to Appdome.

    1. Upload an app to Appdome’s Mobile App Security Build System

    2. Upload Method: Appdome Console or DEV-API
    3. Mobile App Formats: .ipa for iOS, or .apk or .aab for Android
    4. Payload Signing Key Compatible With: Obj-C, Java, JS, C#, C++, Swift, Kotlin, Flutter, React Native, Unity, Xamarin, and more
  2. Build the feature: Payload Signing Key.

    1. Building Payload Signing Key by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the Payload Signing Key feature as shown below:
      2. fusion set that contains Payload Signing Key

        Figure 1: Fusion Set that will contain the Payload Signing Key feature
        Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required).

      3. Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Payload Signing Key feature via Appdome Console, to add the Payload Signing Key feature to this Fusion Set.

      4. Open the Fusion Set Detail Summary by clicking the “...” symbol on the far-right corner of the Fusion Set. Copy the Fusion Set ID from the Fusion Set Detail Summary (as shown below): fusion Set Detail Summary image

        Figure 2: Fusion Set Detail Summary
        Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory).

      5. Follow the instructions below to use the Fusion Set ID inside any standard mobile DevOps or CI/CD toolkit like Bitrise, App Center, Jenkins, Travis, Team City, Circle CI or other system:
        1. Build an API for the app – for instructions, see the tasks under Appdome API Reference Guide
        2. Look for sample APIs in Appdome’s GitHub Repository
    2. Building the Payload Signing Key feature via Appdome Console

      To build the Payload Signing Key protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Anti Bot Tab > MobileBOT™ Defense section.
      2. How: Check whether Session Headers is toggled On (enabled), otherwise enable it . The feature Payload Signing Key is enabled by default, as shown below. Toggle (turn ON) Payload Signing Key, as shown below. Payload Signing Key option

        Figure 3: Add Payload Signing Key option

      3. When you enable Session Headers you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Payload Signing Key

        Fusion Set applied Payload Signing Key

        Figure 4: Fusion Set that displays the newly added Payload Signing Key protection

      4. Click Build My App at the bottom of the Build Workflow (shown in Figure 3).
    Congratulations!  The Payload Signing Key protection is now added to the mobile app
  3. Certify the Payload Signing Key feature in Mobile Apps

    After building Payload Signing Key, Appdome generates a Certified Secure™ certificate to guarantee that the Payload Signing Key protection has been added and is protecting the app. To verify that the Payload Signing Key protection has been added to the mobile app, locate the protection in the Certified Secure™ certificate as shown below: Payload Signing Key shown in Certificate secure

    Figure 5: Certified Secure™ certificate

    Each Certified Secure™ certificate provides DevOps and DevSecOps organizations the entire workflow summary, audit trail of each build, and proof of protection that Payload Signing Key has been added to each Mobile app. Certified Secure provides instant and in-line DevSecOps compliance certification that Payload Signing Key and other mobile app security features are in each build of the mobile app

Using Threat-Events™ for Payload Signing Key Intelligence and Control in Mobile Apps

Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when Payload Signing Key is detected. To consume and use Threat-Events™ for Payload Signing Key in Mobile Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for Payload Signing Key shown below.

The specifications and options for Threat-Events™ for Payload Signing Key are:

Threat-Event™ Elements Add Payload Signing Key Method Detail
Appdome Feature Name Payload Signing Key
Threat-Event Mode
OFF, IN-APP DEFENSE Appdome detects, defends and notifies user (standard OS dialog) using customizable messaging.
ON, IN-APP DETECTION Appdome detects the attack or threat and passes the event in a standard format to the app for processing (app chooses how and when to enforce).
ON, IN-APP DEFENSE Uses Appdome Enforce mode for any attack or threat and passes the event in a standard format to the app for processing (gather intel on attacks and threats without losing any protection).
Certified Secure™ Threat Event Check x
Visible in ThreatScope™ x
Developer Parameters for Adding Payload Signing Key Threat-Event™
Threat-Event NAME
Threat-Event DATA reasonData
Threat-Event CODE reasonCode
Threat-Event REF
Threat-Event SCORE
currentThreatEventScore Current Threat-Event score
threatEventsScore Total Threat-events score
Threat-Event Context Keys
message Message displayed for the user on event
failSafeEnforce Timed enforcement against the identified threat
externalID The external ID of the event which can be listened via Threat Events
osVersion OS version of the current device
deviceModel Current device model
deviceManufacturer The manufacturer of the current device
fusedAppToken The task ID of the Appdome fusion of the currently running app
kernelInfo Info about the kernel: system name, node name, release, version and machine.
carrierPlmn PLMN of the device. Only available for Android devices.
deviceID Current device ID
reasonCode Reason code of the occurred event
buildDate Appdome fusion date of the current application
devicePlatform OS name of the current device
carrierName Carrier name of the current device. Only available for Android.
updatedOSVersion Is the OS version up to date
deviceBrand Brand of the device
deviceBoard Board of the device
buildUser Build user
buildHost Build host
sdkVersion Sdk version
timeZone Time zone
deviceFaceDown Is the device face down
locationLong Location longitude conditioned by location permission
locationLat Location latitude conditioned by location permission
locationState Location state conditioned by location permission
wifiSsid Wifi SSID
wifiSsidPermissionStatus Wifi SSID permission status

With Threat-Events™ enabled (turned ON), Mobile developers can get detailed attack intelligence and granular defense control in Mobile applications and create amazing user experiences for all mobile end users when Payload Signing Key is detected.


The following is a code sample for native Mobile apps, which uses all values in the specification above for Payload Signing Key:


Important! Replace all placeholder instances of <Context Key> with the specific name of your threat event context key across all language examples. This is crucial to ensure your code functions correctly with the intended event data. For example, The <Context Key> could be the message, externalID, OS Version, reason code, etc.



Using Appdome, there are no development or coding prerequisites to build secured Mobile Apps by using Payload Signing Key. There is no SDK and no library to code or implement in the app and no gateway to deploy in your network. All protections are built into each app and the resulting app is self-defending and self-protecting.

Releasing and Publishing Mobile Apps with Payload Signing Key

After successfully securing your app by using Appdome, there are several available options to complete your project, depending on your app lifecycle or workflow. These include:

Related Articles:

How Do I Learn More?

If you have any questions, please send them our way at support.appdome.com or via the chat window on the Appdome platform.

Thank you!

Thanks for visiting Appdome! Our mission is to secure every app on the planet by making mobile app security easy. We hope we’re living up to the mission with your project.

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