> For the complete documentation index, see [llms.txt](https://earn.blink.sv/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://earn.blink.sv/chapter-206-the-evolution-of-money-iv/206.06-lesson-innovative-solution.md). # 206.6 Lesson - satoshisBreakthrough **Screen:** satoshisBreakthrough **Headline:** Satoshi's Breakthrough **Reward:** 3 **Text:** Satoshi's solution to the double spending problem was a breakthrough in computer science and distributed systems. Until Bitcoin, many believed that it would be unsolvable. His solution allowed Satoshi to develop a new electronic cash system that for the first time made it possible for people to send digital money directly to each other, without needing a bank or other organization to help. \================================================================= ## QUIZ **Question:** Which problem did Satoshi have to solve to create Bitcoin? **Answer:** The double spending problem **Feedback:** Good job. Bitcoin uses a proof-of-work consensus mechanism where transactions are batched into blocks and chained together to a blockchain. This way, every user knows that every coin is only spent once **Correct:** true **Answer:** The problem of double coincidence of wants **Feedback:** Not quite. The double coincidence of wants is a problem of barter that can be solved with money. Try again **Correct:** false **Answer:** The halving problem **Feedback:** Hah no. The halving in bitcoin is not a problem, but part of the solution that Satoshi designed! More on that in Chapter 302. Try again! **Correct:** false