The unsolved math problem which could be worth a billion dollars 5

No one on Earth knows how to reverse one of the most popular computer algorithms . Yet it's really easy to compute one - way . You could make billions of dollars if you solved this mathematics problem , which is computed quintillions of times per second in the race for mining Bitcoin . SHA256 has some amazing properties , is useful for digital signatures , cryptography , authentication , and is a central part of the Bitcoin protocol Bitcoin and other " crypto - currencies " rely on one - way hash functions like the SHA - 256 algorithm to secure the blockchain where all the transactions are kept . In this video , I explain Some of the big - picture ideas behind this one function . Other cryptocurrencies use similar ideas . Comments , Suggestions , or errors ? Let me know in the comments , and I'll fix them in an upcoming follow - up video .