The Blockchain

• The blockchain operates within a decentralized network of users.

• The blockchain serves as a foundation for decentralized consensus. (explain consensus with images that illustrate the Byzantine General’s problem graphically)

• Anyone can access the blockchain’s record and audit the activity of its network.

• The blockchain is comprised of blocks of the network users’ activity.

• While many people associate blockchain technology solely with cryptocurrencies or digital money, Ethereum makes it possible to exchange other types of digital information. (list)

• How does the blockchain work? — (illustrations!)

1. activity takes place among users in the network — Slide A
2. their activity is recorded on an unverified list — Slide A
3. the unverified list is locked by a math problem — Slide B
4. when a user’s device in the network solves the math problem, the unverified activity is verified — Slide B
5. the list of newly verified activity is added to the blockchain — Slide C
6. all other users’ devices receive the updated information simultaneously — Slide D
7. consensus is reached — Slide D

• After a block of activity has been added to the blockchain, its transactions cannot be altered or removed.

• The blockchain’s record extends from its last verified transaction to its very first block, often referred to as its genesis block.

• Users can trust the blockchain to maintain a perfect account of their network’s activity.