The objectives $of$ this programming project include $1$ design the structure $of$

a blockchain; $2$ demonstrate the structure $in$ each node $of$ a blockchain; $3$ illustrate the

usage $of$ hashed pointer $in$ a blockchain; $4$ describe how blockchain works; $5$

understand digital signature; $6$ explore the reason that a blockchain can $be$ self$-$verified.

Description: $In$ this project, you are required $to$ make a java code $to$ build a blockchain

including multiple blocks. $In$ each block, $it$ contains a list $of$ transactions, previous hash $-$

the digital signature $of$ the previous block, and the hash $of$ the current block which $is$

based $on$ the list $of$ transactions and the previous hash. $If$ anyone would change anything

with the previous block, the digital signature $of$ the current block will change. When this

changes, the digital signature $of$ the next block will change.