as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
design a proof-of-work system
user
a proof-of-work system consists of a client submitting a challenge (i.e. a mathematical problem) to the server. the server then randomly generates a nonce (i.e. an arbitrary number used only once) and hashes the challenge along with the nonce. the server then checks if the resulting hash meets certain requirements. if it does, the system accepts the solution as a valid answer.
assistant