The author writes "I do not foresee any smartphone app ever being approved for this purpose." (the purpose is 'passing classified information for military operations'), while in fact, I'm not sure I see the issue - all the app (any one of them, including WhatsApp, Signal, etc.) needs to add is what is referred to as 'conditional access' to some chats. Meaning, you can define chats as only authorized for users whose identity is provided by a trusted Identity Provider, or are running on certified devices. This type of security is already implemented in many enterprises, supported by browsers (to some extent, at least), and can be relatively easily be supported by applications. Custom made chat apps already use this (e.g. Workplace Chat, which is used by Meta), and so I'm not sure it's something we won't see supported by other commercial apps messaging apps.

You can't underestimate how much people will screw up operational security (opsec.)

Arch-revolutionary Che Guevara was tracked down and assassinated because the NSA cracked his "unbreakable" one time pads which would have been unbreakable if he'd only used them once.

https://www.kopaldev.de/2022/04/27/cryptography-for-everybod...