End-to-end encryption (E2EE)

End-to-end encryption (E2EE) is a system of communication where only the communicating users can read the messages, preventing third parties – including telecom providers, internet providers, and even the application service provider itself – from accessing the cryptographic keys needed to decrypt the conversation. In E2EE systems, the data is encrypted on the sender's device and can only be decrypted on the recipient's device, making it one of the most secure forms of encryption available for everyday communication.

The technology works by ensuring that the encryption keys are stored exclusively on the endpoints (i.e., users' devices), rather than on servers or other intermediate points. When a message is sent, it's encrypted using the recipient's public key, and can only be decrypted using the corresponding private key, which never leaves the recipient's device. This approach has been implemented in various popular messaging applications like Signal, WhatsApp, and Telegram (in secret chats), making secure communication accessible to everyday users.

E2EE has become increasingly important in the modern digital age, particularly as concerns about privacy, surveillance, and data security have grown. It's a crucial tool for protecting sensitive communications, whether for journalists protecting their sources, activists avoiding government surveillance, or ordinary citizens maintaining their privacy. However, E2EE has also faced challenges from governments and law enforcement agencies who argue it can shield criminal activities, leading to ongoing debates about the balance between privacy and security in digital communications.