Abstract: Random numbers are the cornerstone of information security. The security of information encryption stems from the unpredictability of random numbers, making high-entropy random number generators a crucial requirement in cryptography. Randomness, as the most vital property of random numbers, has been extensively studied and discussed. This paper introduces the fundamental characteristics of randomness, the historical development of random number generators, the quantum advantages of quantum random number generators, and recent domestic and international advances in this field.