If you want some more convenience but don't want to give up security, you can use hardware tokens like Nitrokey with GPG.
The process would be generate a random file using dd and /dev/urandom. Set this as the key for FDE. Encrypt it using your GPG and store it on /boot. Have a helper script to ask you plugin your Nitrokey and (optional) pin to decrypt the keyfile to have root decrypted. I had read this on some blog for dm-crypt so you will need to research and adopt to your setup.
My point is metadata should be protected as content does. While IM platform needs to know which message should be delived to whom, they don't need that after being delivered, nor have it profiled.
they make clear to you that Facebook can and will have some metadata, but not the contents of the chat itself.
You thought you're safe and private when the content is encrypted? LOL, no. Metadata are much more useful to Facebook, and to the intelligence services.
“We Kill People Based on Metadata.” -- General Michael Hayden, former Director of NSA and CIA
You can. I'm not particularly familar with Thunderbird, but you can export your key to system/user keyring then you can sign any data you want using GPG. However, I doubt tool exists for you to embed the signature to a PDF like x.509 signing would.
For whatever reason, ppl need SMS OTP. While Telegram is using SMS operators (like Twilio), it can't covers all users globally (which the truth is more about cost and regulations), thus this program is born to cover (bypass) it.
It uses your number to sent the OTP code to random numbers on Telegram behalf, up to 150 per month including international SMS, where you bear the cost and aknowledging your number will be seen by who recieve it. In return, if your monthly send SMS reaches the quota, Telegram will reward you with a monthly Telegram Premium Subscription (which cost almost nothing to them).
GPG is painful. No doubt. But with the pain it gains agility. Any single apps and protocols enables secure communication, being TLS, Tor, GPG or any one you listed, can draw attention. However, apps are more vulnerable. Their traffic pattern can be analysed and block individually while GPG is protocol agnostic. Look how China GFW had block many E2EE apps/protocols.
In today's world, secure communication apps like SimpleX are more in flavor as it is way easier to use. I used them daily as my main communication method. But it's also good to learn GPG as a backup when those apps fails.
The government's move is in line with a recent policy that has targeted services with end-to-end encryption. A host of encrypted apps were blocked at the start of last year — including the likes of Threema, Element, Wickrme, and Safeswiss — and the government is going after WhatsApp to disable end-to-end encryption, although it isn't clear how that would even work.
This is why GPG is still an important and valuable tool. You can use it on litteral anything and not relying on single point of failure. Paired with steganography no one will know the message even existed. Yet, not many are willing to learn nor support this anymore.
Edit: use of more conservative wording
Edit 2: correct spelling
I agree, but this doesn't rule off the possiblity of a government to deliberately calls out truth as "fake news" or "disinfornation". Especially some authoritarian regimes to downplay the event.
His warning is valid. While I trust professionals and specialists, I shall also use my brain to make sure what they said make sense.
If you want some more convenience but don't want to give up security, you can use hardware tokens like Nitrokey with GPG.
The process would be generate a random file using
ddand/dev/urandom. Set this as the key for FDE. Encrypt it using your GPG and store it on/boot. Have a helper script to ask you plugin your Nitrokey and (optional) pin to decrypt the keyfile to have root decrypted. I had read this on some blog for dm-crypt so you will need to research and adopt to your setup.