Blockchain accounting process, how to verify the broadcast?

generate a new transaction

When a new transaction is generated, it will be broadcast to other participating nodes in the blockchain network

Each node puts several new transactions into the block

Each node will collect several unverified transaction Hash values into blocks, and each block can contain hundreds or thousands of transactions

Decide who will verify these transactions

Each node calculates the proof of work to determine who can verify the transaction, and the node that calculates the result the fastest will verify the transaction. This is the way to achieve consensus.

The node that has obtained the verification right broadcasts the block to all nodes

The node that completes the POW fastest will broadcast its own block to other nodes

Each node verifies and connects the new block

Other nodes will confirm whether the transaction contained in this block is valid, and accept the block after confirming that it has not been double spent and has a valid digital signature. At this time, the block is officially connected to the blockchain, and the data cannot be tampered with.

Transaction verification complete

Once all nodes accept the block, the blocks that have not completed the POW work before will become invalid, and each node will re-create a block to continue the next POW calculation work.

Explain the POA of the blockchain consensus mechanism in detail

The full name of POA is proof of activity. It is not an independent consensus algorithm, but a hybrid algorithm of POW and POS . Currently, VeChain and Ouchain have adopted the POA consensus mechanism.

The general process of the POA algorithm is as follows. Each active node continuously performs hash calculations to find block headers whose hash values are less than a specific value. The block header includes the previous block hash value, the address of the local node, and the block number. and the nonce value .

When a node finds a block header that meets the conditions, it will broadcast the block header to the entire network, and all active nodes receive the broadcast for verification. If the verification is passed, the block header in the broadcast will be used as the data source to derive N random equity owners, and all active nodes will judge whether they are lucky equity owners. If you are one of the previous N-1 lucky shareholders, you will once sign the above block header with your private key. And broadcast this signature on the whole network. If you are the Nth lucky equity holder, use this block header to construct a new block, which contains as many transactions as possible selected by yourself, and the signatures of the first N-1 lucky equity holders Also has its own signature to the hash of the full blockchain. Then broadcast the signed full node on the whole network. All active nodes are verified after receiving full nodes. If the verification is passed, the node is considered to be a legal new block. Add it to the blockchain.

If this block belongs to the longest chain, take it as the previous block and go back to the initial step, otherwise it will be discarded. It is not difficult to find that the POA algorithm requires all N lucky people to be online, and any lucky shareholder who is not online will cause the block to be discarded.

This is also the origin of the active proof. The POA algorithm will periodically count the number of discarded blocks. And adjust the value of N according to this. If the number of discarded blocks is large, then reduce N, otherwise increase N.

The block loss of the POA algorithm is a kind of computing power loss. In the POA algorithm. The transaction fee in the block is shared by the publisher of the block and n lucky stakeholders.

The most important thing about the POA algorithm is that it can prevent non-severe attackers. The so-called non-powerful attack refers to an attacker who has a powerful algorithm but only holds a small amount of equity. The POS part of the POA algorithm makes it very rare for non-powerful people to get the chance to build blocks. We should not be able to effectively attack.

In the POA algorithm, lucky shareholders rely on capital to make profits, and this idea is to receive dividends for holding shares. This mechanism will estimate that the long-term continuation of this equity by shareholders is conducive to the preservation of digital assets and the reduction of volatility.

The pow part of POAstay public controls the speed at which new block headers are generated through the difficulty of the hash algorithm. Play a role in stabilizing the network and avoiding forks.

However, the acquisition of the above advantages also comes at a price, the power loss caused by the pow part. The pos part leads to the loss of the new block header and a relatively high probability, resulting in a waste of computing power.

Use blockchain technology to realize encrypted storage verification without remembering passwords, and solve the problem of offline safe storage

This article introduces a method of network security verification using blockchain technology with personal storage devices

The fast and encrypted storage devices that do not remember passwords represented by Weidu have perfectly achieved fast and safe storage, but the fly in the ointment is that it is impossible to query when the device is used through the network, and it is impossible to predict that the device will be cracked offline in extreme cases.

Using blockchain technology can solve this problem, the specific working principle:

After the device is connected to the PC and detects that the radio frequency ID has passed the verification, it is connected to the specific hardware in the device. At this time, the program installed on the PC will automatically broadcast information such as the opening time of the device to a specific blockchain network. After being confirmed by the blockchain network, the access to the storage granules that store the important data of the user at the back end of the device is authorized. Because every time the device is turned on, network authorization and related information are stored on the blockchain network, so it is effective to prevent people with unknown purposes from secretly opening the device without the user's knowledge.

Has the network verification of an extra layer of blockchain improved the security of the device a lot?