The memory-hard hash function Argon2 is optimized for security, clarity, and efficiency. It can be used for password hashing, key derivation, and memory-hard It supersedes our previous PHC submission Argon in all aspects, especially speed.
Argon2 is a new hash function, which summarizes the state of the art in the design of memory-hard functions. It is a streamlined and simple design. It aims at the highest memory filling rate and effective use of multiple computing units, while still providing defense against tradeoff attacks. Argon2 is optimized for the x86 architecture and exploits the cache and memory organization of the recent Intel and AMD processors. Argon2 has two variants: Argon2d and Argon2i.
Argon2d is faster and uses data-depending memory access, which makes it suitable for cryptocurrencies and applications with no threats from side-channel timing attacks. Argon2i uses data-independent memory access, which is preferred for password hashing and password-based key derivation.
Argon2i is slower as it makes more passes over the memory to protect from tradeoff attacks. It summarizes the research our group has done in the concept of memory-hard functions and uses a number of novel ideas to achieve very high performance.
Argon2 is scalable. It may occupy any integer number of KBytes, and its performance depends strongly linearly on the memory use. Unlike some other schemes the total memory does not have to be a power of two. Argon is also efficient and can be parallelized on up to 256 threads/cores that share the same memory.
Research paper "Fast and Tradeoff-Resilient Memory-Hard Functions for Cryptocurrencies and Password Hashing". Introduces Argon2 and its fast-verification feature.