- Define elements of trust in a blockchain
- Discuss consensus protocol
- Explain "Trust"
- Establishing Trust in a Blockchain
- Secure chain using protocols
- Validate transactions & blocks
- Verify availability of resources
- Executing & confirming transactions
- Steps one and two are validate transaction and check resources
- About 20 criteria are validated
- The syntax, the transaction signature, time stamp, nonce, gas limit, sender account balance, transaction signatures, fuel, or gas points and other resources available
- Step three is execute transactions
- Merkle tree hash of the validated transactions is computed
- Miners execute the transaction or smart contracts for either transfer
Proof of Work
Robustness is the ability to satisfactorily manage exceptional situations.
- What if more than one miner solves the consensus puzzle where it close in time to each other?
- Bitcoin protocol allows this chain split or two chains for the next cycle
- The probability that the next block will happen at the same time is extremely low
- Winner of the next cycle for block creation consolidates one of the chains and becomes the accepted chain
- The transaction in the other blocks are returned to the unconfirmed pool
- Ethereum handles this by allowing Omar or Runner-Up blocks and allocating a small incentive for these Runner-Up blocks
- Double spending
- Digital currency and other consumables can be reused in transactions
- Bitcoin allows the first transaction that reference the digital asset and reject the rest of the transaction that reference the same digital asset
- In Ethereum, a combination of account number and a global nonce is used to address the doublet spending issue
- Soft fork
- A minor process adjustment has to be carried out typically by bootstrapping a new software to the already running processes
- A software patch or a bug fix to address an issue
A major change in the protocol
After a hard fork the emerging two chains are incompatible
In Oct 17, 2017, a few Ethereum improvement proposals (EIP) planned a hard fork
Proof of Work consensus still stays except that every hundred block, proof of Stake consensus protocol is applied for evaluating the latter
- Minor incentive was reduced from 5 ethers to 3 ethers for block creation.
These are just few EIPs.
Soft fork and hard fork in the blockchain word are like the release of software patches,
and new versions of operating systems respectively.
Forks are mechanisms that add to the robustness of the blockchain framework.
Well-managed forks help build credibility in the blockchain by providing approaches to manage unexpected faults and planned improvements.