What is blockchain
June 9, 2019•361 words
1. The technology behind bitcoin.
2. Blockchain can be described as a chain of blocks - block: digital information, and chain: public database.
--------------------------------------------------------
:
- information about transactions, e.g. date, time, dollar amount of your recent purchase.
- information about participant, e.g. your name (a unique digital signature, like a username), Amazon.com, Inc.
- information that distinguishes it from other blocks, e.g. a unique code called 'hash'.
-Note: A single block on the blockchain can store up to 1MB of data. Depending on the size of transactions, a single block can contain a few thousand transactions.
--------------------------------------------------------
:
- A transaction occurs.
- Transaction must be verified by a network of computers. E.g., when you make a purchase, a network of computers will check if your transaction happened in the way you said it did, by confirming the details of the purchase e.g. time, dollar amount, participants.
- Transaction is stored in a block, joining the hundreds or thousands of others like it.
- The block is given a hash, and the hash of the most recent block added before.
-Note: When a new block is added to blockchain, it becomes publicly available for anyone to view, including you.
-Note2: Bitcoin's blockchain gives one access to transaction data, along with information about when, where, and by who the block was added.
--------------------------------------------------------
:
- One does not have access to identifying information about the users making transactions; it is anonymous.
- If information on the block is edited, a math function that turns digital information into a string of numbers and letters gives it a NEW HASH. Therefore, once a hacker tries to edit a block (transaction details), the hash changes. This But since the next block in the chain still contains the old has, the hacker will need to update that next block too, but that means they need to update every single block after it on the blockchain.
-Note: once a block is added to the blockchain, it becomes very difficult to edit and impossible to delete.
--------------------------------------------------------
- Bitcoin exchange is the public blockchain that bitcoin uses.