ChaCha20
ChaCha20 is a symmetric stream cipher designed for high-speed encryption and security, developed by Daniel J. Bernstein as an improvement over the Salsa20 cipher. It operates by generating a pseudorandom keystream from a key and nonce, which is then XORed with plaintext to produce ciphertext, making it efficient for software implementations on modern CPUs. It is widely used in protocols like TLS, SSH, and WireGuard for secure data transmission.
Developers should learn ChaCha20 when implementing encryption in applications requiring fast, secure data protection, especially on devices with limited hardware acceleration for AES. It is ideal for real-time communication, VPNs, and disk encryption where performance and resistance to timing attacks are critical. Its simplicity and proven security make it a preferred choice in modern cryptographic protocols.