block_example <- list(index = 1,
timestamp = "2018-11-02 08.32 IST",
data = "Infoway",
previous_hash = 0,
proof = 9,
new_hash = NULL)
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library("digest")
digest("Manish" ,"sha256")
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hash_block <- function(block){
block$new_hash <- digest(c(block$index,
block$timestamp,
block$data,
block$previous_hash), "sha256")
return(block)
}
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# Increment the proof number until a number is found that is divisable by 99 and by the proof of the previous block
proof_of_work <- function(last_proof){
proof <- last_proof + 1
while (!(proof %% 99 == 0 & proof %% last_proof == 0 )){
proof <- proof + 1}
return(proof) }
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gen_new_block <- function(previous_block){
new_proof <- proof_of_work(previous_block$proof)
new_block <- list(index = previous_block$index + 1,
timestamp = Sys.time(),
data = paste0("this is block ", previous_block$index +1),
previous_hash = previous_block$new_hash,
proof = new_proof)
new_block_hashed <- hash_block(new_block)
return(new_block_hashed) }
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block_genesis <- list(index = 1,
timestamp = Sys.time(),
data = "Genesis Block",
previous_hash = "0",
proof = 1)
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blockchain <- list(block_genesis)
previous_block <- blockchain[[1]]
# How many blocks should we add to the chain after the genesis block
num_of_blocks_to_add <- 5
# Add blocks to the chain
for (i in 1: num_of_blocks_to_add){
block_to_add <- gen_new_block(previous_block)
blockchain[i+1] <- list(block_to_add)
previous_block <- block_to_add
print(cat(paste0("Block ", block_to_add$index, " has been added", "\n",
"\t", "Proof: ", block_to_add$proof, "\n",
"\t", "Hash: ", block_to_add$new_hash))) }
