Proof of Work

What:

• A special number to the very end of a block in the ledger.
• The SHA-256 of the block concatenated with this special number should end up having n trailing 0’s.
• Because of how hashing works, the only way to have figured this out would be to have checked every single previous number individually.

Motivation:

There’s an inherent problem when working with distributed ledgers. How do you verify that a change that you make, is heard by other nodes, and in the same order? What can you do to ensure someone else’s ledger looks the same as yours?

• Use “Proof Of Work”
• Fraudulent transactions would be computationally infeasible to introduce.