- The FACT0RN blockchain uses factoring as its PoW instead of traditional methods. - The challenge is to generate semiprimes (numbers with two prime factors) without knowing the factors in advance. - Miners are rewarded for finding strong semiprimes by factoring them. - The PoW problem is to find a nonce, offset, and the smallest prime factor of a semiprime that satisfies specific conditions. - The smallest prime factor must be submitted to measure the work done for PoW. - The blockchain introduces a "deadpool" where users can submit numbers to be factored by paying a fee. - The reward for factoring is exponential in shape but limited to avoid excessive inflation. - The design principles of the blockchain prioritize security, game theory, economics, and heuristics.