Keep in mind that with secure messaging, if the other side gets compromised, your chats with them are compromised. This seems obvious, but with signal groups of a large size, they're effectively public groups. Signal insists on using your phone number too, refusing user ids or anything that will make analysis hard.
Don't use Signal for organizing anything of this sort, I promise you'll regret it. I've heard people having better luck with Briar, but there might be others too. I only know that Signal and Whatsapp are what you want to avoid. Unless your concern is strictly cryptographic attacks of your chat's network-traffic and nothing more.
Don't use Signal for organizing anything of this sort, I promise you'll regret it. I've heard people having better luck with Briar, but there might be others too. I only know that Signal and Whatsapp are what you want to avoid. Unless your concern is strictly cryptographic attacks of your chat's network-traffic and nothing more.