ChaCha20
- is a symmetric stream cipher encryption algorithm
- developed by Daniel J. Bernstein
- known for its simple ARX (Addition-Rotation-XOR) operations, making it suitable for hardware and software implementation, especially on mobile devices and systems without AES acceleration
- it is commonly used with Poly1305 as an authenticated encryption with associated data (AEAD) algorithm, providing both confidentiality and data integrity
- is widely adopted in protocols like TLS 1.3, WireGuard, and OpenSSH