Signal is not the place for top secret communications, but it might be the right choice for you – a cybersecurity expert on what to look for in a secure messaging app
Keeping your chats secure is a good idea, but end-to-end encryption is just the beginning of the list of options to consider when picking a messaging app.
Signal is the place for top secret communications, but not for any government business, top secret or not (at least not when using a public instance - they could fork the project to keep decryptable records on gov servers where the official gov instance would run).
at least not when using a public instance - they could fork the project to keep decryptable records on gov servers where the official gov instance would run
All the people in the chat were high enough that the government for free provided them with secure rooms in their homes so everything would be done through government hardware and encryption programs.
The protections for classified information are not just about information security. They are about physical and operational security as well. That's why s SCIF has a "two locks" policy, and requires things like 4" steel doors.
Govs have their own apps, email servers, various other web-based tools to exchange data, etc. Usually also gov hardware (ie can't use/access such gov apps on non-gov phones).
It's not "what's better" it's what is mandated/required/the law.
Much like when you get a regular average job you have to use whatever is permitted - company email is the usual, can't just deal with company data over your private email account where the company has no oversight.