Argon2is

Argon2id is a hybrid memory-hard password hashing function. It was designed to be resistant to various types of attacks, including brute-force attacks, side-channel attacks, and GPU-accelerated attacks. Argon2id is the recommended version of Argon2 by the Password Hashing Competition (PHC).

The "id" in Argon2id stands for "interactive" and "data-independent." Interactive means that the algorithm can be tuned to resist different types of attacks based on the specific needs of the application. Data-independent means that the algorithm's memory access pattern is not predictable, making it harder for attackers to exploit side-channel information.

Argon2id combines the strengths of Argon2d and Argon2i. Argon2d is resistant to GPU-accelerated attacks, while Argon2i is resistant to side-channel attacks. By interleaving the two, Argon2id offers a strong defense against both.

Key parameters for Argon2id include the memory cost (m), the time cost (t), and the parallelism (p). The memory cost determines the amount of RAM required to compute the hash, the time cost determines the number of iterations, and the parallelism determines the number of threads that can be used. Higher values for these parameters increase the security but also increase the computational cost.

Argon2id is designed to be a drop-in replacement for existing password hashing algorithms like bcrypt and scrypt, offering improved security against modern hardware and attack techniques. Its flexibility allows developers to configure it to balance security and performance requirements.