This document provides an introduction to Ethereum and blockchain technology. It explains that Ethereum allows for the creation of programmable smart contracts and decentralized applications on a blockchain. It then defines blockchain as a distributed database of blocks containing transaction data secured through proof of work. Key components of blockchain like blocks, transactions, mining, and wallets are described at a high level.
4. What is
Blockchain?
It’s a chain of blocks…
• Distributed database of blocks
• Transaction
• Proof of work
• Wallets
5. Blocks
• Structure
• Hash = digital signature
• Previous hash
• Timestamp
• Data
• Genesis block = first block
6. Transactions
• Public key (address) of the sender
• Public key (address) of the receiver
• Value/amount of funds
• Transaction ID
• Signature
• allow only the owner to spend their coins
• Inputs
• Outputs
7. Proof of work
(mining)
• Miners or validators?
• Finding a block
• nonce number
• Consensus on difficulty
• Block generation interval (10 minutes in Bitcoin)
• Difficulty adjustment interval (in blocks)
• Reward
8. Wallets
• Generating key pairs
• Elliptic cryptography
• Losing your private key = losing your wallet
• Private key
• Used for signing transactions
(so nobody could spend your coins)
• Public key act as address
• Used for receiving a payment
Hello everyone,
My name is Aleksandar, I’m frontend developer working in Polar Cape mostly with JavaScript frameworks and lately I have interest in blockchain technology and that is what I will talk about today.
Things that I will talk about on this presentation are why we need this technology what is blockchain how to create your own coin using Ethereum
It all started 9 years ago when Bitcoin was (introduced) the first blockchain, it all started from there. Everyone talked about it, no body believed at that time. It is focused on payments mining and trading coins and so on. After bitcoin there were other crypto currencies like litecoin, ripple. But I think the most important one for the developers is Ethereum. Is Ethereum similar to Bitcoin? Well, sort of, but not really. The structure of the ethereum blockchain is very similar to bitcoin's, in that it is a shared record of the entire transaction history. Every node on the network stores a copy of this history.
Ethereum is a world computer – public blockchain. The biggest power is that it is programmable
Smart contracts have code written in solidity
You will find a lot of definitions on internet about what really is blockchain, a lot of blockchain experts will say different things, but lets stick to the simplest one, it is a chain of blocks. Simple as that. It is a dist. Db of blocks stored on each node of the network. Each block has transactions (one or more). In order to add the block into the blockchain it needs to be validated first by the miners who do a proof of work.
On the other hand we have wallets where we can see information about how many coins we own.
If we go in to details, each block has the following structure
Calculated hash by previous hash timestamp and data
The private key is used to sign the data and the public key can be used to verify its integrity.
proves the owner of the address is the one sending this transaction and that the data hasn’t been changed. ( for example: preventing a third party from changing the amount sent
In order to add a block in the chain, you need to validate it first. That is called proof of work. In public networks that is done by other computers called miners
“Mining” is basically just trying a different nonce until the hash matches the difficulty.