Autolykos2 (Chepurnoy et al. 2020) is a proof-of-work (PoW) algorithm designed to address some of the concerns around the energy efficiency and centralization of traditional PoW algorithms such as SHA-256 and Ethash (used by Bitcoin and Ethereum, respectively).
One of the main features of Autolykos2 is its asymmetry, which refers to the fact that it requires different amounts of memory for different types of hardware. This makes it more difficult for specialized ASIC miners to gain an advantage over general-purpose hardware, such as GPUs.
Another key feature of Autolykos2 is its memory-hardness, which means that it requires a large amount of memory to calculate the proof of work. This property makes it more resistant to specialized hardware and can help to prevent centralization of mining power.
Autolykos2 is also designed to be non-outsourceable, which means that it is difficult to perform the computations required by the algorithm on cloud-based services or remote servers. This helps to ensure that mining is done by individuals and small groups, rather than large mining pools.
Additionally, Autolykos2 introduces a new construct, the "Access Mask", which controls the memory access of the puzzle algorithm, making it more resilient to the implementation of specialized hardware, like FPGA and ASIC, to solve the puzzle.