Double Ratchet Algorithm
The Double Ratchet Algorithm is a cryptographic protocol designed for secure, end-to-end encrypted messaging that provides forward secrecy and future secrecy (also known as post-compromise security). It enables two parties to exchange messages with evolving encryption keys, ensuring that even if a key is compromised, past and future communications remain protected. This algorithm is widely used in modern messaging applications like Signal, WhatsApp, and others to maintain privacy in real-time conversations.
Developers should learn and use the Double Ratchet Algorithm when building secure messaging systems that require robust protection against eavesdropping and key compromise, such as in chat apps, encrypted email, or any application handling sensitive user data. It is essential for implementing end-to-end encryption with properties like forward secrecy, which prevents past messages from being decrypted if long-term keys are stolen, and future secrecy, which secures future messages after a compromise.