ChaCha2012

ChaCha2012 is a variant of the ChaCha20 stream cipher. ChaCha20 is a symmetric key stream cipher that generates a pseudorandom stream of bits. This stream is then combined with the plaintext using a bitwise XOR operation to produce the ciphertext. The "20" in ChaCha20 refers to the number of rounds the core function performs.

ChaCha2012 specifically indicates that the cipher operates with 20 rounds. It uses a 256-bit key and a 64-bit nonce. The original ChaCha cipher, proposed by Daniel J. Bernstein, was designed to be fast and efficient on modern processors, particularly those without dedicated hardware acceleration for AES. Its design emphasizes simplicity and resistance to various cryptanalytic attacks.

The "2012" nomenclature is sometimes used to distinguish it from other variants, such as ChaCha12, which performs 12 rounds. The increased number of rounds in ChaCha20 compared to ChaCha12 generally provides a higher security margin, although at the cost of slightly reduced performance. ChaCha20 and its variants have gained significant adoption in various security protocols and software due to their strong performance and security characteristics. It is a widely trusted and implemented cryptographic primitive.