What is the HashKey algorithm?

Could you please explain to me in simple terms what the HashKey algorithm is all about? I've heard it's an important concept in the world of cryptocurrency and blockchain technology, but I'm not quite sure how it works or what its purpose is. Is it related to encryption or security in some way? And how does it help to ensure the integrity and security of transactions on a blockchain? I'd really appreciate a clear and concise explanation to help me better understand this complex topic.