Cryptography
ChaCha20
Definition
A modern stream cipher designed by Daniel J. Bernstein, using a 256-bit key and 96-bit nonce, widely deployed alongside Poly1305 as the AEAD ChaCha20-Poly1305.
Examples
- TLS 1.3 and QUIC use TLS_CHACHA20_POLY1305_SHA256 on mobile devices.
- WireGuard encrypts all data packets with ChaCha20-Poly1305.
Related terms
Salsa20
A 256-bit-key stream cipher designed by Daniel J. Bernstein in 2005, selected by the eSTREAM portfolio and the direct ancestor of ChaCha20.
Stream Cipher
A symmetric cipher that encrypts data one bit or byte at a time by XORing it with a pseudorandom keystream derived from a key and nonce.
AES (Advanced Encryption Standard)
A NIST-standardized 128-bit block cipher with 128-, 192- or 256-bit keys, designed by Daemen and Rijmen and used as the dominant symmetric cipher worldwide.
Symmetric Encryption
An encryption scheme in which the same secret key is used for both encryption and decryption, offering high speed and strong confidentiality when the key is shared securely.
Encryption
The cryptographic transformation of plaintext into ciphertext using an algorithm and key so that only authorized parties can recover the original data.
Cipher Suite
A named combination of cryptographic algorithms — key exchange, authentication, bulk encryption, and integrity — negotiated by protocols such as TLS for a given session.