The technology that enables encrypted messaging between users is known as end-to-end encryption. This security measure ensures that messages are only readable by the intended recipients, preventing unauthorized access during transmission. Each message is encrypted on the sender's device and only decrypted on the recipient's device, making it virtually impossible for third parties, including service providers, to intercept and read the messages. Technologies and protocols such as Signal Protocol and SSL/TLS are commonly employed to establish secure communications in applications like WhatsApp and Signal.