For the complete documentation index, see llms.txt

Device hash

The device hash risk indicator allows you to identify and manage MobileID devices associated with a single physical device.

By correlating seemingly unrelated users to a single device, you can proactively detect and prevent fraud attempts, such as account takeovers.

How it works

During the MobileID registration of a new device, the client SDK automatically generates a unique device hash (deviceHash). This hash remains consistent for the physical device, even if your application is uninstalled and reinstalled.

By monitoring the deviceHash across your user base, we can identify anomalies.

Example

For example, if a single device hash is suddenly tied to an unusually high number of users, it could strongly indicate that a bad actor is using one device to cycle through compromised accounts.

What is a device hash?

A device hash is a unique and persistent digital fingerprint used to identify a specific mobile device within your app.

It is a SHA-256 hash of a unique ID generated for the device. The source of this unique ID differs depending on the platform:

Platform	Source of unique ID
Android	It is derived from the Settings.Secure.ANDROID_ID value in the Android SDK.
iOS	It is generated by the SDK using Apple's CFUUIDCreate function and stored in the end-user's iCloud Keychain.

Configuration options

You can configure the number of users that can be associated with a single device hash before it is flagged as suspicious.

Default configuration

By default, a device hash is flagged as suspicious if it is associated with more than two users. This means that this value is set to 2.

To update this configuration, you can use the Update device hash configuration endpoint in the MobileID Admin API.

How to take action

You can monitor and manage suspicious device hashes directly from the Signicat Dashboard. This allows you to mitigate risks quickly and protect your end-users.

To learn more about the actions that you can take, see the sections below:

Investigate devices

You can retrieve a complete list of all users and devices tied to a flagged device hash. To do this:

1. Go to Signicat Dashboard > Products > MobileID > Risk indicators > Device hash.
2. From this page, you can see the following data from the last six months:

   Data name	Description
   Unique device hashes	The total number of unique device hashes that have been generated by the MobileID SDK.
   Active users	The total number of users who have active devices associated with the MobileID SDK.
   Flagged device hashes	A summary of device hashes that have been flagged as potentially suspicious.

3. To learn more about a flagged device hash, click the Check details button next to it. Here, you see a list of user IDs associated with it.
4. To learn more about the device IDs associated with a user ID, click the dropdown arrow next to it. Here, you see the following data:

   Data name	Description
   Device ID	The unique identifier for the MobileID device.
   Last used	The timestamp when the MobileID device last carried out an operation.
   Status	The current state of the MobileID device. Possible values: This can be either ACTIVE, LOCKED, or DELETED.

Lock devices

You can lock active MobileID devices associated with a suspicious device hash to prevent them from being used for authentication or signing.

There are three lock flows that you can carry out:

• Lock a single device associated with a suspicious device hash.
• Lock all devices for a given user ID associated with a suspicious device hash.
• Lock all devices for all user IDs associated with a suspicious device hash.

To do this:

1. Go to Signicat Dashboard > Products > MobileID > Risk indicators > Device hash.
2. Under the Flagged device hashes section, click the Check details button next to a suspicious device hash.
3. Follow the steps in the table below according to the lock flow that you want to carry out:

   Action	Description
   Lock a single device	Click the dropdown arrow next to a user ID, then click the Lock button beside the device ID that you want to lock.
   Lock all devices for a user	Click the dropdown arrow next to a user ID, then click the Lock all devices for this user button.
   Lock all devices for all users	Click the Lock for all users button.

Unlock devices

You can unlock locked MobileID devices associated with a suspicious device hash to allow them to be used for authentication or signing again.

You can only unlock a single device at a time. To do this:

1. Go to Signicat Dashboard > Products > MobileID > Risk indicators > Device hash.
2. Under the Flagged device hashes section, click the Check details button next to a suspicious device hash.
3. Click the dropdown arrow next to a user ID, then click the Unlock button beside the device ID that you want to unlock.

Block device hash

You can add a device hash to a blocklist to prevent any new MobileID devices from being created on that physical device in the future.

This operation also locks any existing MobileID devices that are associated with the device hash, which prevents them from being used for authentication or signing.

To block a device hash:

1. Go to Signicat Dashboard > Products > MobileID > Risk indicators > Device hash.
2. Under the Flagged device hashes section, click the Check details button next to a suspicious device hash.
3. Click the Block device hash button.
4. To confirm, click the Yes, block device hash button.

Unblock device hash

You can unblock a previously blocked device hash to allow new MobileID devices to be created on that physical device again.

Important

When you block a device hash, all associated devices are automatically locked. Unblocking the device hash does not automatically unlock these devices. You must manually unlock any devices that you wish to use again.

To unblock a device hash:

1. Go to Signicat Dashboard > Products > MobileID > Risk indicators > Device hash.
2. Under the Flagged device hashes section, click the Check details button next to a blocked device hash.
3. Click the Unblock device hash button.
4. To confirm, click the Yes, unblock device hash button.

How to get access

The Device hash risk indicator is part of an add-on for MobileID. To get access to this feature, contact sales.

Free trial

This add-on product comes with a free trial period!

Once you have access, you do not need to configure anything to start capturing data. The deviceHash is an Always collected risk attribute in the MobileID SDKs, meaning it is collected automatically by default.