Similar to hard drives and removable disks, communication channels can also be encrypted by protecting data with a complex cipher so that communication can only be accessed (decrypted) with a password or key. Of course, for journalists and human rights activists encryption is a key component of ensuring secure communication with confidential sources. This can be done in a variety of ways.

In messaging services, we know that third parties store the data, such as messages and calls, and that the data is only encrypted in transit, which can be a problem if privacy is needed at all points of communication. End-to-end encryption (E2EE) keeps messages encrypted and private from everyone, including the provider of the messaging service. The sender is one “end” of the conversation and the recipient is the other “end”, which leads to the name “end-to-end”. Basically, it's like when you send a scrambled letter through a postal service, nobody can read your letter except you and the person to whom you sent it.

Emails can be encrypted using PGP (Pretty Good Privacy), which is based on public key cryptography. You need to generate a key pair - a public key that you share with others and a private key that you keep secret - in order to exchange encrypted emails with correspondents.

If you use an email provider like Gmail or Outlook, you can encrypt your communication using Thunderbird, an open-source email client with built-in OpenPGP capabilities, or by using the Mailvelope browser extension which works with popular webmail services.

However, there are email providers, such as ProtonMail or Tuta, which encrypt your messages automatically when they are sent between their users and also provide ways to send encrypted emails to those using other providers. Please refer to these Proton and Tuta guides on how to send password protected emails to users on other email providers.