Some platforms are supported only via PCL. Ungortunately some platform-level API’s are not available there. Still there is a way to use platform API’s and RO SDK or Data Abstract together.
This code snippet contains a full implementation of AES encryption envelope for Xamarin platform.
Main Xamarin app (iOS or Android one, I tested on both). It references
1.1. Data Access class library
1.2. Data Abstract for PCL build (or RemObjects SDK for PCL build of no Data Abstract features are needed) assemblies
In  that has both full access to the Xamarin platform framework implement AES encryption/decryption envelope. So when the data access is performed instantiate the AesEncryptionEnvelope, provide it to the DataModule class defined in the data access PCL library, attach it there to the Message instance and finally access the data.
CustomAesEncryptionEnvelope.cs (5.7 KB)