Beta version:

# 1. Install our official public software signing key wget -O- https://updates.signal.org/desktop/apt/keys.asc | gpg --dearmor > signal-desktop-keyring.gpg cat signal-desktop-keyring.gpg | sudo tee -a /usr/share/keyrings/signal-desktop-keyring.gpg > /dev/null

# 2. Add our repository to your list of repositories echo 'deb [arch=amd64 signed-by=/usr/share/keyrings/signal-desktop-keyring.gpg] https://updates.signal.org/desktop/apt xenial main' |\ sudo tee -a /etc/apt/sources.list.d/signal-xenial.list

# 3. Update your package database and install signal sudo apt update && sudo apt install signal-desktop-beta

https://support.signal.org/hc/en-us/articles/360007318471-Si...

Non-beta version:

# NOTE: These instructions only work for 64-bit Debian-based # Linux distributions such as Ubuntu, Mint etc.

# 1. Install our official public software signing key: wget -O- https://updates.signal.org/desktop/apt/keys.asc | gpg --dearmor > signal-desktop-keyring.gpg cat signal-desktop-keyring.gpg | sudo tee /usr/share/keyrings/signal-desktop-keyring.gpg > /dev/null

# 2. Add our repository to your list of repositories: echo 'deb [arch=amd64 signed-by=/usr/share/keyrings/signal-desktop-keyring.gpg] https://updates.signal.org/desktop/apt xenial main' |\ sudo tee /etc/apt/sources.list.d/signal-xenial.list

# 3. Update your package database and install Signal: sudo apt update && sudo apt install signal-desktop

https://signal.org/download/

Do you not see any difference with this and "it's included in the distribution and vetted by a distribution developer"?

No. The way I see it, I'm downloading an open-source, *always* end-to-end encrypted desktop-application Signal from official repository, instead of downloading an open-source *never* end-to-end encrypted desktop-application Telegram from official repository. Having to add the ppa is 10 seconds of additional trouble. I'll live. Without end-to-end encryption, a lot of dissidents however, might not.

10 seconds of additional trouble, a lifetime of root access to a 3rd party :)

What? You have factual evidence Signal's apt repo is installing rootkits to people's computers? Let's see it.

I have factual evidence once you add it they have root access.

I can't predict the future.

So, you have nothing. Best of luck.