> I learned in college that most random number generators use the current timestamp to generate a pseudo-random number. > How does this differ cryptographicall

> I learned in college that most random number generators use the current timestamp to generate a pseudo-random number. > How does this differ cryptographically from algorithms like MWC1616 and xorshift128+ in backend applications? How can a random number generator be vulnerable to attacks in real life? In the early days of online poker some people made a killing by figuring out all the possible hands from the PRNGs being used and then they could just start a game and look up the hands they'd been dealt in their database.