End-to-end encryption will improve things but it is still only as secure as your key management. For email to be convenient you need an easy way to get you friend's public key and easy ways are hard to make secure.
Without a trust the only thing that comes close is an in person P2P pairing ceremony.
Key management might work in an enterprise setting with a central authority, but making sure your friend's public key isn't swapped with the government's is pretty hard if you don't trust the cloud provider, telecom, or intermediate infrastructure.
Without a trust the only thing that comes close is an in person P2P pairing ceremony.
Key management might work in an enterprise setting with a central authority, but making sure your friend's public key isn't swapped with the government's is pretty hard if you don't trust the cloud provider, telecom, or intermediate infrastructure.