First lecture of the Bitcoin and cryptocurrency technologies online course.

For the accompanying textbook, including the free draft version, see: bitcoinbook.cs.princeton.edu/

In this lecture (click the time to jump to the section):
* Cryptographic hash functions 1:51
* Hash pointers and data structures 20:28
* Digital signatures 29:25
* Public keys as identities 39:04
* A simple cryptocurrency 44:39