An algorithm is a sequence of clear instructions used to solve a problem. Cuckoo Cycle is a memory-bound graph-theoretic proof-of-work algorithm. Because of the nature of this algorithm, it is a hindrance in terms of producing Application-Specific Integrated Circuits (ASICs). Unlike general purpose circuits that run on your smartphone or computer, ASICs are integrated circuits designed specifically to focus on a limited set of operations, which make them very cost and energy efficient in terms of mining. A modified version of the Cuckoo Cycle is being used as the mining algorithm for the æternity blockchain. In this way, even if ASICs are being produced for other projects such as the privacy oriented blockchain Grin, the ASICs would not work for æternity. Additionally, if modifications are made to the algorithm, then the ASIC hardware may end up being a doorstopper. Some view ASICs as evil as centralization of mining power could occur, while others are more welcoming to them since ASICs provide the necessary power to perform the hashing on the network. It still remains a controversial topic today.