---
title: "Creating a shareable ASM for iOS"
slug: "dpo-authenticator-sdk-for-ios-creating-a-shareable-asm"
updated: 2026-10-27T20:13:21Z
published: 2026-10-27T20:13:21Z
canonical: "docs.onespan.com/dpo-authenticator-sdk-for-ios-creating-a-shareable-asm"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.onespan.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Creating a shareable ASM for iOS

If your system design requires your ASM to share keychain entries and app storage across multiple apps, use the following steps as a guide during implementation:

1. Create the metadata and new AAID for your shareable authenticator.
2. Implement the descriptor for this authenticator, e.g. SampleAuthnenticatorDescriptor.cpp
  1. Define the AAID
  2. Set aaidInfo.isShareable = true
3. Implement a factory class, e.g. NNLSampleAuthenticatorDXFactory.mm and add a function for creating an instance, e.g. nnl::asmsdk::IAuthenticatorDescriptor * createSampleShareableInstance()
4. Create an Access Group string for sharing and use it when storing items in the keychain:
  1. Get the value of the SharedGroupAccess entry from the application main bundle: NSString *groupName = [[NSBundle mainBundle].infoDictionary objectForKey:@"SharedAccessGroup"];
  2. Create a strSharedAccessGroup using Bundle SeedID and SharedGroupAccess, e.g.: strSharedAccessGroup = strBundleSeedID + "." + groupName;
  3. Add the corresponding attribute when storing data in the keychain, e.g.: [dict setObject:strSharedAccessGroup forKey:(__bridge id)kSecAttrAccessGroup];

Note the following additional design considerations:

- Your authenticator must also be able to share biometric templates across apps.
- You should implement locking to prevent corruption due to concurrent accesses.
- Apps can be upgraded independently of each other, so it’s important to validate data consistency across versions.