Signal uses the DRM APIs to mitigate threats like Microsoft Recall, but it doesn't stop the app itself from reading its own data.
I don't really see how it's possible to mitigate client compromise. You can decrypt stuff on a secure enclave but at some point the client has to pull it out and render it.
I don't really see how it's possible to mitigate client compromise. You can decrypt stuff on a secure enclave but at some point the client has to pull it out and render it.