Blockchain: Proof-of-Life — Part II
By Taha Dhailey on ALTCOIN MAGAZINE
Welcome to Part II of Blockchain as a *not* published database. You can get Part I of this small series here.
In this, we will dive into the consensus of Proof-of-Life and look into incidents of Julian Assange and Vitalik Buterin, on how they buffed off rumours about their death/assassination.
In Jan 2017, rumours claimed Julian Assange had been assassinated, so Julian Assange read the bitcoin block 447506 hash to prove himself alive and in June same year Vitalik Buterin, the founder of Ethereum also did the same by reading ethereum block hash.
You guys might be scratching your head right now, wondering how can anyone prove themselves alive like this. Well, just stay with me till the end to know.
Every block in the blockchain is made up of n number of arbitrary transactions until it has reached its block capacity (1mb for bitcoin block & block gas limit for ethereum), it also depends on the miner for how many transactions he/she like to add to his/her block since more tranxs equals to more tranx fees.
Conclusion: Every block has an unknown number of transactions with unknown miner
At the same time, there are hundreds and thousands of solo/pool miners are in the race with their own block filled with arbitrary tranxs to win the Proof of Work competition trying to solve the target hash with the Merkle root hash (all tranx bundled and hashed as shown in figure below) and previous block hash.
The miner aims to get a hash less than the target hash which is not a fixed value
Conclusion: Winning miner’s hash to the POW(also block hash) is arbitrary and unknown
As we also know, hashes are collision-resistant and puzzle friendly, so its impossible to predict a hash (based on broad random data set).
Looking at the behaviour of miners and unknown target hash value and properties of hash, it becomes practically impossible to predict the block hash before its time.
Conclusion: The block hash is unpredictable because it’s a hash.
Hence as per the above conclusions, the event of reading hash proves that this event cannot be before the timestamp of block creation, it has to be after the block creation, and that is after the block timestamp.
With the above, these famous individuals were able to prove themselves alive hence called Proof-of-Life consensus.
I hope you enjoyed this small series. Thank you.
