Peer A

#
#
#
#
#

Peer B

#
#
#
#
#

Peer C

#
#
#
#
#

Welcome to Blockchain Demo!

Lab 3:The Blockchain

Let's examine the blockchain by referencing our screen, which contains 5 blocks, each labeled according to position.

Step 1:
TYPE OR COPY AND PASTE THE FOLLOWING INTO THE DATA FIELD OF BLOCK #1, VERBATIM AND CLICK “MINE”:

John bought the house from Tom for 100 dollars

Step 2:
TYPE OR COPY AND PASTE THE FOLLOWING INTO THE DATA FIELD OF BLOCK #2, VERBATIM AND CLICK “MINE”:

Tom sold the house to Steve for 150 dollars

Step 3:
TYPE OR COPY AND PASTE THE FOLLOWING INTO THE DATA FIELD OF BLOCK #3, VERBATIM AND CLICK “MINE”:

Steve sold the house to George for 300 dollars

Step 4:
TYPE OR COPY AND PASTE THE FOLLOWING INTO THE DATA FIELD OF BLOCK #4, VERBATIM AND CLICK “MINE”:

George sold the house to Mike for 350 dollars

Step 5:
TYPE OR COPY AND PASTE THE FOLLOWING INTO THE DATA FIELD OF BLOCK #5, VERBATIM AND CLICK “MINE”:

Mike sold the house to Megan for 500 dollars

Step 6:
GO TO BLOCK #2 AND CHANGE THE AMOUNT FROM 150 DOLLARS TO 100 DOLLARS AND CLICK “MINE”.

Notice how the chain of blocks changes from green to red. The data has been tampered with in one of the blocks and the chain of blocks has been broken.

Now if this chain of blocks had been distributed and stored across a distributed network to other peers, this chain would no longer match the ledger of the other peers on the network.


Please return back to EdX


Acknowledgement: Special shoutout to Anders Brownsworth for letting us borrow his Awesome Blockchain Demo example to create a lab!