Blockchain

This project is an implementation of the research article, "Analysis of the Blockchain Protocol in Asynchronous Networks" written by Rafael Pass, Lior Seeman, and Abhi Shelat, and the blockchain protocol where the program will create a blockchain with hash values, a digital signature and an actual transaction. With Netbeans IDE 8.2 and a Macbook Pro with 32GB RAM and an Intel i9 processor, I was able to create a JAVA program that creates virtual blocks and an actual blockchain between the blocks. The blocks have a digital signature, a unique transaction and a timestamp. Each block has a current hash value and a previous hash value that matches the current hash value of the previous block. The first block is an empty non-real block because it has no previous hash value since there is no block before it. All of this goes through the SHA-256 algorithm. After the hash algorithm completes, the program outputs the block hash values. The program also authenticates whether the current hash value and previous hash value of the blocks are equal or not. If they are not equal, then the blockchain would not be valid. If they are equal, then the blockchain is valid and ready to go. The program also outputs and tells the user if the blockchain is valid or not. Even if a single block in the program is not valid, the entire blockchain would be invalid and output "null".