The document discusses the history and development of a new technology called blockchain, which uses cryptography to allow decentralized control and security for digital currencies like Bitcoin without the need for centralized authorities. Blockchain works by distributing transaction records across a network of computer systems instead of storing them in one location, and requires consensus of the majority of participants to confirm new blocks of transactions, making it very difficult to modify transaction histories without detection. The technology is still in early stages but has potential for other applications beyond digital currencies.

1. 1

2. 2

3. 3

4. 4

5. 5

6. 6

7. 7

8. 8

9. 9

10. 10

11. 11

12. 12

13. 13

14. 14

15. 15

16. 16

17. 17

18. 18

19. 19

20. 20