Agnes  Sauer

Agnes Sauer

1598573280

Building a SIEM: combining ELK, Wazuh HIDS

When putting together a SIEM, one of the first things that you need to decide on is the distributed architecture you’re going to choose. This means analyzing the resources available, as well as the needs of your SOC.

  • Are you monitoring 100, 1000, or 10000 hosts?
  • Do you have budget for commercial tools?
  • How heterogeneous is your infrastructure?
  • Are you just looking for security alerts, or do you also need persistent event logging for auditing purposes?
  • What type of granularity are you looking to achieve?
  • What response time do you wish to achieve? Do you need real time notifications?
  • Do you have time to improve/tune your solution or do you need something working 100% ASAP?

These are some of the questions you need to ask yourself. In our particular case, we needed to set up a SIEM for a network of about 20K hosts. We didn’t have a budget for commercial tools or licenses. We needed persistent logging for auditing purposes. This included logging every command executed in our infrastructure, while monitoring for malicious ones. We also wanted low level granularity in order to write custom rules. Basically, we wanted a top-level SOC without spending money. But this is not possible.

#blue-team #infosec #soc #siem #security

What is GEEK

Buddha Community

Building a SIEM: combining ELK, Wazuh HIDS
Agnes  Sauer

Agnes Sauer

1598573280

Building a SIEM: combining ELK, Wazuh HIDS

When putting together a SIEM, one of the first things that you need to decide on is the distributed architecture you’re going to choose. This means analyzing the resources available, as well as the needs of your SOC.

  • Are you monitoring 100, 1000, or 10000 hosts?
  • Do you have budget for commercial tools?
  • How heterogeneous is your infrastructure?
  • Are you just looking for security alerts, or do you also need persistent event logging for auditing purposes?
  • What type of granularity are you looking to achieve?
  • What response time do you wish to achieve? Do you need real time notifications?
  • Do you have time to improve/tune your solution or do you need something working 100% ASAP?

These are some of the questions you need to ask yourself. In our particular case, we needed to set up a SIEM for a network of about 20K hosts. We didn’t have a budget for commercial tools or licenses. We needed persistent logging for auditing purposes. This included logging every command executed in our infrastructure, while monitoring for malicious ones. We also wanted low level granularity in order to write custom rules. Basically, we wanted a top-level SOC without spending money. But this is not possible.

#blue-team #infosec #soc #siem #security

The Best Way to Build a Chatbot in 2021

A useful tool several businesses implement for answering questions that potential customers may have is a chatbot. Many programming languages give web designers several ways on how to make a chatbot for their websites. They are capable of answering basic questions for visitors and offer innovation for businesses.

With the help of programming languages, it is possible to create a chatbot from the ground up to satisfy someone’s needs.

Plan Out the Chatbot’s Purpose

Before building a chatbot, it is ideal for web designers to determine how it will function on a website. Several chatbot duties center around fulfilling customers’ needs and questions or compiling and optimizing data via transactions.

Some benefits of implementing chatbots include:

  • Generating leads for marketing products and services
  • Improve work capacity when employees cannot answer questions or during non-business hours
  • Reducing errors while providing accurate information to customers or visitors
  • Meeting customer demands through instant communication
  • Alerting customers about their online transactions

Some programmers may choose to design a chatbox to function through predefined answers based on the questions customers may input or function by adapting and learning via human input.

#chatbots #latest news #the best way to build a chatbot in 2021 #build #build a chatbot #best way to build a chatbot

Riyad Amin

Riyad Amin

1571046022

Build Your Own Cryptocurrency Blockchain in Python

Cryptocurrency is a decentralized digital currency that uses encryption techniques to regulate the generation of currency units and to verify the transfer of funds. Anonymity, decentralization, and security are among its main features. Cryptocurrency is not regulated or tracked by any centralized authority, government, or bank.

Blockchain, a decentralized peer-to-peer (P2P) network, which is comprised of data blocks, is an integral part of cryptocurrency. These blocks chronologically store information about transactions and adhere to a protocol for inter-node communication and validating new blocks. The data recorded in blocks cannot be altered without the alteration of all subsequent blocks.

In this article, we are going to explain how you can create a simple blockchain using the Python programming language.

Here is the basic blueprint of the Python class we’ll use for creating the blockchain:

class Block(object):
    def __init__():
        pass
    #initial structure of the block class 
    def compute_hash():
        pass
    #producing the cryptographic hash of each block 
  class BlockChain(object):
    def __init__(self):
    #building the chain
    def build_genesis(self):
        pass
    #creating the initial block
    def build_block(self, proof_number, previous_hash):
        pass
    #builds new block and adds to the chain
   @staticmethod
    def confirm_validity(block, previous_block):
        pass
    #checks whether the blockchain is valid
    def get_data(self, sender, receiver, amount):
        pass
    # declares data of transactions
    @staticmethod
    def proof_of_work(last_proof):
        pass
    #adds to the security of the blockchain
    @property
    def latest_block(self):
        pass
    #returns the last block in the chain

Now, let’s explain how the blockchain class works.

Initial Structure of the Block Class

Here is the code for our initial block class:

import hashlib
import time
class Block(object):
    def __init__(self, index, proof_number, previous_hash, data, timestamp=None):
        self.index = index
        self.proof_number = proof_number
        self.previous_hash = previous_hash
        self.data = data
        self.timestamp = timestamp or time.time()
    @property
    def compute_hash(self):
        string_block = "{}{}{}{}{}".format(self.index, self.proof_number, self.previous_hash, self.data, self.timestamp)
        return hashlib.sha256(string_block.encode()).hexdigest()

As you can see above, the class constructor or initiation method ( init()) above takes the following parameters:

self — just like any other Python class, this parameter is used to refer to the class itself. Any variable associated with the class can be accessed using it.

index — it’s used to track the position of a block within the blockchain.

previous_hash — it used to reference the hash of the previous block within the blockchain.

data—it gives details of the transactions done, for example, the amount bought.

timestamp—it inserts a timestamp for all the transactions performed.

The second method in the class, compute_hash , is used to produce the cryptographic hash of each block based on the above values.

As you can see, we imported the SHA-256 algorithm into the cryptocurrency blockchain project to help in getting the hashes of the blocks.

Once the values have been placed inside the hashing module, the algorithm will return a 256-bit string denoting the contents of the block.

So, this is what gives the blockchain immutability. Since each block will be represented by a hash, which will be computed from the hash of the previous block, corrupting any block in the chain will make the other blocks have invalid hashes, resulting in breakage of the whole blockchain network.

Building the Chain

The whole concept of a blockchain is based on the fact that the blocks are “chained” to each other. Now, we’ll create a blockchain class that will play the critical role of managing the entire chain.

It will keep the transactions data and include other helper methods for completing various roles, such as adding new blocks.

Let’s talk about the helper methods.

Adding the Constructor Method

Here is the code:

class BlockChain(object):
    def __init__(self):
        self.chain = []
        self.current_data = []
        self.nodes = set()
        self.build_genesis()

The init() constructor method is what instantiates the blockchain.

Here are the roles of its attributes:

self.chain — this variable stores all the blocks.

self.current_data — this variable stores information about the transactions in the block.

self.build_genesis() — this method is used to create the initial block in the chain.

Building the Genesis Block

The build_genesis() method is used for creating the initial block in the chain, that is, a block without any predecessors. The genesis block is what represents the beginning of the blockchain.

To create it, we’ll call the build_block() method and give it some default values. The parameters proof_number and previous_hash are both given a value of zero, though you can give them any value you desire.

Here is the code:

def build_genesis(self):
        self.build_block(proof_number=0, previous_hash=0)
 def build_block(self, proof_number, previous_hash):
        block = Block(
            index=len(self.chain),
            proof_number=proof_number,
            previous_hash=previous_hash,
            data=self.current_data
        )
        self.current_data = []  
        self.chain.append(block)
        return block

Confirming Validity of the Blockchain

The confirm_validity method is critical in examining the integrity of the blockchain and making sure inconsistencies are lacking.

As explained earlier, hashes are pivotal for realizing the security of the cryptocurrency blockchain, because any slight alteration in an object will result in the creation of an entirely different hash.

Thus, the confirm_validity method utilizes a series of if statements to assess whether the hash of each block has been compromised.

Furthermore, it also compares the hash values of every two successive blocks to identify any anomalies. If the chain is working properly, it returns true; otherwise, it returns false.

Here is the code:

def confirm_validity(block, previous_block):
        if previous_block.index + 1 != block.index:
            return False
        elif previous_block.compute_hash != block.previous_hash:
            return False
        elif block.timestamp <= previous_block.timestamp:
            return False
        return True

Declaring Data of Transactions

The get_data method is important in declaring the data of transactions on a block. This method takes three parameters (sender’s information, receiver’s information, and amount) and adds the transaction data to the self.current_data list.

Here is the code:

def get_data(self, sender, receiver, amount):
        self.current_data.append({
            'sender': sender,
            'receiver': receiver,
            'amount': amount
        })
        return True

Effecting the Proof of Work

In blockchain technology, Proof of Work (PoW) refers to the complexity involved in mining or generating new blocks on the blockchain.

For example, the PoW can be implemented by identifying a number that solves a problem whenever a user completes some computing work. Anyone on the blockchain network should find the number complex to identify but easy to verify — this is the main concept of PoW.

This way, it discourages spamming and compromising the integrity of the network.

In this article, we’ll illustrate how to include a Proof of Work algorithm in a blockchain cryptocurrency project.

Finalizing With the Last Block

Finally, the latest_block() helper method is used for retrieving the last block on the network, which is actually the current block.

Here is the code:

def latest_block(self):
        return self.chain[-1]

Implementing Blockchain Mining

Now, this is the most exciting section!

Initially, the transactions are kept in a list of unverified transactions. Mining refers to the process of placing the unverified transactions in a block and solving the PoW problem. It can be referred to as the computing work involved in verifying the transactions.

If everything has been figured out correctly, a block is created or mined and joined together with the others in the blockchain. If users have successfully mined a block, they are often rewarded for using their computing resources to solve the PoW problem.

Here is the mining method in this simple cryptocurrency blockchain project:

def block_mining(self, details_miner):
            self.get_data(
            sender="0", #it implies that this node has created a new block
            receiver=details_miner,
            quantity=1, #creating a new block (or identifying the proof number) is awarded with 1
        )
        last_block = self.latest_block
        last_proof_number = last_block.proof_number
        proof_number = self.proof_of_work(last_proof_number)
        last_hash = last_block.compute_hash
        block = self.build_block(proof_number, last_hash)
        return vars(block)

Summary

Here is the whole code for our crypto blockchain class in Python:

import hashlib
import time
class Block(object):
    def __init__(self, index, proof_number, previous_hash, data, timestamp=None):
        self.index = index
        self.proof_number = proof_number
        self.previous_hash = previous_hash
        self.data = data
        self.timestamp = timestamp or time.time()
    @property
    def compute_hash(self):
        string_block = "{}{}{}{}{}".format(self.index, self.proof_number, self.previous_hash, self.data, self.timestamp)
        return hashlib.sha256(string_block.encode()).hexdigest()
    def __repr__(self):
        return "{} - {} - {} - {} - {}".format(self.index, self.proof_number, self.previous_hash, self.data, self.timestamp)
class BlockChain(object):
    def __init__(self):
        self.chain = []
        self.current_data = []
        self.nodes = set()
        self.build_genesis()
    def build_genesis(self):
        self.build_block(proof_number=0, previous_hash=0)
    def build_block(self, proof_number, previous_hash):
        block = Block(
            index=len(self.chain),
            proof_number=proof_number,
            previous_hash=previous_hash,
            data=self.current_data
        )
        self.current_data = []  
        self.chain.append(block)
        return block
    @staticmethod
    def confirm_validity(block, previous_block):
        if previous_block.index + 1 != block.index:
            return False
        elif previous_block.compute_hash != block.previous_hash:
            return False
        elif block.timestamp <= previous_block.timestamp:
            return False
        return True
    def get_data(self, sender, receiver, amount):
        self.current_data.append({
            'sender': sender,
            'receiver': receiver,
            'amount': amount
        })
        return True        
    @staticmethod
    def proof_of_work(last_proof):
        pass
    @property
    def latest_block(self):
        return self.chain[-1]
    def chain_validity(self):
        pass        
    def block_mining(self, details_miner):       
        self.get_data(
            sender="0", #it implies that this node has created a new block
            receiver=details_miner,
            quantity=1, #creating a new block (or identifying the proof number) is awared with 1
        )
        last_block = self.latest_block
        last_proof_number = last_block.proof_number
        proof_number = self.proof_of_work(last_proof_number)
        last_hash = last_block.compute_hash
        block = self.build_block(proof_number, last_hash)
        return vars(block)  
    def create_node(self, address):
        self.nodes.add(address)
        return True
    @staticmethod
    def get_block_object(block_data):        
        return Block(
            block_data['index'],
            block_data['proof_number'],
            block_data['previous_hash'],
            block_data['data'],
            timestamp=block_data['timestamp']
        )
blockchain = BlockChain()
print("GET READY MINING ABOUT TO START")
print(blockchain.chain)
last_block = blockchain.latest_block
last_proof_number = last_block.proof_number
proof_number = blockchain.proof_of_work(last_proof_number)
blockchain.get_data(
    sender="0", #this means that this node has constructed another block
    receiver="LiveEdu.tv", 
    amount=1, #building a new block (or figuring out the proof number) is awarded with 1
)
last_hash = last_block.compute_hash
block = blockchain.build_block(proof_number, last_hash)
print("WOW, MINING HAS BEEN SUCCESSFUL!")
print(blockchain.chain)

Now, let’s try to run our code to see if we can generate some digital coins…

Wow, it worked!

Conclusion

That is it!

We hope that this article has assisted you to understand the underlying technology that powers cryptocurrencies such as Bitcoin and Ethereum.

We just illustrated the basic ideas for making your feet wet in the innovative blockchain technology. The project above can still be enhanced by incorporating other features to make it more useful and robust.

Learn More

Thanks for reading !

Do you have any comments or questions? Please share them below.

#python #cryptocurrency

What is BUILD Finance (BUILD) | What is BUILD Finance token | What is BUILD token

BUILD Finance DAO

The document is non-binding. Some information may be outdated as we keep evolving.

BUILD Philosophy

BUILD Finance is a decentralised autonomous venture builder, owned and controlled by the community. BUILD Finance produces, funds, and manages community-owned DeFi products.

There are five core activities in which the venture BUILDers engage:

  1. Identifying business ideas,
  2. Organising teams,
  3. Sourcing capital,
  4. Helping govern the product entities, and
  5. Providing shared services.

BUILD operates a shared capabilities model, where the DAO provides the backbone support and ensures inter-entity synergies so that the product companies can focus on their own outcomes.

BUILD takes care of all organisational, hiring, back/mid office functions, and the product companies focus on what they can do best, until such time where any individual product outgrows the DAO and becomes fully self-sustainable. At that point, the chick is strong enough to leave the nest and live its own life. The survival of the fittest. No product entity is held within DAO by force.

Along the way, BUILD utilises the investment banking model, which, in its essence, is a process of creating assets, gearing them up, and then flipping them into a fund or setting them as income-generating business systems, all this while taking fees along the way at each step. BUILD heavily focuses on integrating each asset/product with each other to boost productive yield and revenues. For example, BUILD’s OTC Market may be integrated with Metric Exchange to connect the liquidity pools with the trading traffic. The net result – pure synergy that benefits each party involved, acting in a self-reinforcing manner.

El Espíritu de la Colmena (The Spirit of the Beehive)

BUILD is a hive and is always alive. While some members may appear more active than others, there’s no central source of control or “core teams” as such. BUILD is work in progress where everyone is encouraged to contribute.

Following the natural free market forces, BUILD only works on those products that members are wanting to work on themselves and that they believe have economic value. Effectively, every builder is also a user of BUILD’s products. We are DeFi users that fill the gaps in the ecosystem. Any member can contribute from both purely altruistic or ultra-mercantile intentions – it’s up to the wider community to decide what is deemed valuable and what product to support. The BUILD community is a sovereign individual that votes with their money and feet.

BUILD members = BUILD users. It’s that simple.

$BUILD TOKEN

Tokenomics

$BUILD token is used as a governance token for the DAO. It also represents a pro-rata claim of ownership on all DAO’s assets and liabilities (e.g. BUILD Treasury and $bCRED debt token).

The token was distributed via liquidity mining with no pre-sale and zero founder/private allocation. The farming event lasted for 7 days around mid-Sep 2020. At the time, BUILD didn’t have any products and held no value. Arguably, $BUILD has still zero value as it is not a legal instrument and does not guarantee or promise any returns to anyone. See the launch announcement here https://medium.com/@BUILD_Finance/announcing-build-finance-dc08df585e57​

Initial supply was 100,000 $BUILD with 100% distributed via fair launch. Subsequently, the DAO unanimously voted to approve minting of extra 30,000 $BUILD and allocate them as:

  • 15,000 $BUILD (11.5%) to the founding member of the DAO (@0xdev0) with 1-year gradual vesting, and
  • 15,000 $BUILD (11.5%) to the DAO treasury as development funds.

For the proposal of the above see: https://forum.letsbuild.finance/t/proposal-2-fund-the-development-of-defi-lending-platform/24​

The voting took place at a later retired web-page https://vote.letsbuild.finance. The governance has since moved to Snapshot (link below). The results of the old proposals are not visible there, however, on-chain voting contract can be see here: https://etherscan.io/address/0xa8621477645f76b06a41c9393ddaf79ddee63daf#readContract​

$Build Token Repartition

Vesting Schedule

Minting keys are not burnt = $BUILD supply is not fixed as token holders can vote on minting new tokens for specific reasons determined by the token holders. For example, the DAO may mint additional tokens to incentivise usage of its products, which would, in turn, increase the value flow or TVL. Dilution is not in the economic benefit of the token holders, hence any such events has to be considered carefully.

Access to minting function is available via on-chain governance. A safe buffer is established in a form of the contract-enforced 24 hour delay, which should provide a sufficient time for the community to flag. Meaning that before such a transaction could be executed, everyone would be able to act in advance by withdrawing their funds / exiting from BUILD. Any malicious minting would, theoretically, result in an immediate market sell-off of $BUILD, making it economically detrimental to do such an action. This makes it highly improbable that any malicious minting would be performed_._

GOVERNANCE

All components of the BUILD DAO and the control over its have been decentralised:

  • All contracts (incl. the Treasury and Basis Gold) can be operated by $BUILD holders with on-chain proposals (see https://docs.build.finance/build-knowledge-base/on-chain-voting);
  • All social accounts (Discord, Telegram, and Twitter) are managed by multiple moderators;
  • All frontends (Metric Exchange, Basis Gold, and the BUILD homepage) are auto-deployed and managed by multiple devs.

TREASURY & DEVELOPMENT

BUILD DAO Treasury

The BUILD treasury has over $400k that can be managed by on-chain proposals and used in whichever way the community desires. For example, to hire developers. Having a functioning product, enough funds in the treasury and a fully decentralised governance has been a long-term goal since the inception in September 2020, and now it’s finally here.

Current holdings are (might be outdated):

  • Capital budget (dev / incentives fund) - 11,025 $BUILD (~$94k);
  • Operational budget (product development) - 204,300 $aDAI;
  • Ownership stake - 200,000 $METRIC (~$84k);
  • Ownership stake - 199,900 $UPDOWN(~$62k);
  • Ownership stake - 5,400 $HYPE (~$1.3k);
  • Ownership stake - 2% of $BSGS supply.
  • TOTAL: ~$445k

Funding of the Development

In an early stage, the development will be funded by an allocation of bCRED debt tokens for development expenses. After the first product was built (i.e. Metric Exchange), the DAO sold 5,000 $BUILD for 203,849 $DAI which will now be used for funding of other products or a combination of revenue + a smaller token allocation. This is up to the community to decide.

Smart Contract Audit

Contracts are not audited. It’s up to the BUILD community governance to decide how to spend our funds. If the community wants to spend any amount for auditing, a voting proposal can be initiated. As with any decisions and proposals, the cost-benefit analysis must be employed in regards to the economical sense of spending any funds on audit vs developing more products and expanding our revenue streams.

DAO Liabilities and $bCRED

$bCRED is a token that allowed the DAO to reward members for work before the DAO source sufficient funds. Effectively, $bCRED is a promissory note or an IOU to give back $DAI at 1:1 ratio, when the DAO starts generating revenues. Read more about $bCRED here: https://medium.com/@BUILD_Finance/what-is-bcred-b97e4cc75f8c.

“BUILDER” User Role in Discord

Since Discord is our primary coordination mechanism, we need to make effort to keep it focused on producing value. During the launch of METRIC, we’ve doubled our total number of users! This made it very difficult for existing users to explain what BUILD is about to new users and created a lot of confusion.

To help improve the quality of conversations, we’ve introduced a new user role called BUILDer. BUILDers will have write-access to product development channels while everyone else will only be able to read them. This should keep those product changes focused on actual productive conversations and make them more informative.

“GUARDIAN” Role in Discord

To increase our collective output as a community, a governance vote introduced an incentivisation mechanism for community contribution, tipping, and other small projects using our unique bCRED token (but may change in the future as required). These tokens are stewarded by active community members — “guardians’’ — who are free to allocate these funds to tip people for proactive work. Current guardians are @Son of Ishtar and @0xdev0, although anyone can propose the tip for anyone else. For more details see Proposal #15.

Hence, Guardians are defined as members of the DAO who are entrusted with a community budget for tipping other members for performing various small tasks.

PRODUCT SUITE & ROADMAP

  • Metric Exchange - is a DEX aggregator that allows for limit orders trading for any ERC-20 token via 0x relayer. Development continues with the product owner SHA_2048 and inputs from vfat. Live at metric.exchange.
  • Basis Gold - a synthetic, algorythmically-adjusted token pegged to the price of gold (sXAU) with elastic supply. Live at https://basis.gold/.
  • Updown Finance - binary options for volatility trading instrument (alpha is live at updown.finance).
  • Vortex - a lending & borrowing platform, which will target the long tail of assets that are currently not served by the existing DeFi money markets. Aiming to launch by March’2021.

The other immediate focus right now will be to make good use of our newly available funding and hire several product managers for other projects.

Please note that nothing is here set in stone. Just like any other start-up, we’ll keep experimenting, learning, and evolving. What’s listed here is just our current trajectory but it might change at any point.

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Thank you for reading!

#blockchain #cryptocurrency #build finance #build

Erstellen Sie Ihre eigene Kryptowährungs-Blockchain in Python

Kryptowährung ist eine dezentralisierte digitale Währung, die Verschlüsselungstechniken verwendet, um die Erzeugung von Währungseinheiten zu regulieren und den Geldtransfer zu überprüfen. Anonymität, Dezentralisierung und Sicherheit gehören zu seinen Hauptmerkmalen. Kryptowährung wird von keiner zentralisierten Behörde, Regierung oder Bank reguliert oder verfolgt.

Blockchain, ein dezentralisiertes Peer-to-Peer (P2P)-Netzwerk, das aus Datenblöcken besteht, ist ein wesentlicher Bestandteil der Kryptowährung. Diese Blöcke speichern chronologisch Informationen über Transaktionen und halten sich an ein Protokoll für die Kommunikation zwischen Knoten und die Validierung neuer Blöcke. Die in Blöcken aufgezeichneten Daten können nicht geändert werden, ohne dass alle nachfolgenden Blöcke geändert werden.

In diesem Artikel erklären wir, wie Sie mit der Programmiersprache Python eine einfache Blockchain erstellen können.

Hier ist die grundlegende Blaupause der Python-Klasse, die wir zum Erstellen der Blockchain verwenden:

class Block(object):
    def __init__():
        pass
    #initial structure of the block class 
    def compute_hash():
        pass
    #producing the cryptographic hash of each block 
  class BlockChain(object):
    def __init__(self):
    #building the chain
    def build_genesis(self):
        pass
    #creating the initial block
    def build_block(self, proof_number, previous_hash):
        pass
    #builds new block and adds to the chain
   @staticmethod
    def confirm_validity(block, previous_block):
        pass
    #checks whether the blockchain is valid
    def get_data(self, sender, receiver, amount):
        pass
    # declares data of transactions
    @staticmethod
    def proof_of_work(last_proof):
        pass
    #adds to the security of the blockchain
    @property
    def latest_block(self):
        pass
    #returns the last block in the chain

Lassen Sie uns nun erklären, wie die Blockchain-Klasse funktioniert.

Ausgangsstruktur der Blockklasse

Hier ist der Code für unsere anfängliche Blockklasse:

import hashlib
import time
class Block(object):
    def __init__(self, index, proof_number, previous_hash, data, timestamp=None):
        self.index = index
        self.proof_number = proof_number
        self.previous_hash = previous_hash
        self.data = data
        self.timestamp = timestamp or time.time()
    @property
    def compute_hash(self):
        string_block = "{}{}{}{}{}".format(self.index, self.proof_number, self.previous_hash, self.data, self.timestamp)
        return hashlib.sha256(string_block.encode()).hexdigest()

Wie Sie oben sehen können, nimmt der Klassenkonstruktor oder die Initiationsmethode ( init ()) die folgenden Parameter an:

self— Wie jede andere Python-Klasse wird dieser Parameter verwendet, um auf die Klasse selbst zu verweisen. Auf jede Variable, die der Klasse zugeordnet ist, kann über sie zugegriffen werden.

index — Es wird verwendet, um die Position eines Blocks innerhalb der Blockchain zu verfolgen.

previous_hash — Es wurde verwendet, um auf den Hash des vorherigen Blocks innerhalb der Blockchain zu verweisen.

data—it gibt Details zu den getätigten Transaktionen an, zum Beispiel den gekauften Betrag.

timestamp—it fügt einen Zeitstempel für alle durchgeführten Transaktionen ein.

Die zweite Methode in der Klasse, compute_hash , wird verwendet, um den kryptografischen Hash jedes Blocks basierend auf den obigen Werten zu erzeugen.

Wie Sie sehen können, haben wir den SHA-256-Algorithmus in das Kryptowährungs-Blockchain-Projekt importiert, um die Hashes der Blöcke zu erhalten.

Sobald die Werte im Hashing-Modul platziert wurden, gibt der Algorithmus einen 256-Bit-String zurück, der den Inhalt des Blocks angibt.

Das ist es, was der Blockchain Unveränderlichkeit verleiht. Da jeder Block durch einen Hash repräsentiert wird, der aus dem Hash des vorherigen Blocks berechnet wird, führt die Beschädigung eines Blocks in der Kette dazu, dass die anderen Blöcke ungültige Hashes haben, was zum Bruch des gesamten Blockchain-Netzwerks führt.

Aufbau der Kette

Das ganze Konzept einer Blockchain basiert darauf, dass die Blöcke aneinander „verkettet“ sind. Jetzt erstellen wir eine Blockchain-Klasse, die die entscheidende Rolle bei der Verwaltung der gesamten Kette spielt.

Es behält die Transaktionsdaten bei und enthält andere Hilfsmethoden zum Vervollständigen verschiedener Rollen, z. B. das Hinzufügen neuer Blöcke.

Sprechen wir über die Hilfsmethoden.

Hinzufügen der Konstruktormethode

Hier ist der Code:

class BlockChain(object):
    def __init__(self):
        self.chain = []
        self.current_data = []
        self.nodes = set()
        self.build_genesis()

Die Konstruktormethode init () instanziiert die Blockchain.

Hier sind die Rollen seiner Attribute:

self.chain — Diese Variable speichert alle Blöcke.

self.current_data — Diese Variable speichert Informationen über die Transaktionen im Block.

self.build_genesis() — Diese Methode wird verwendet, um den Anfangsblock in der Kette zu erstellen.

Aufbau des Genesis-Blocks

Die build_genesis()Methode wird verwendet, um den Anfangsblock in der Kette zu erstellen, dh einen Block ohne Vorgänger. Der Genesis-Block ist der Anfang der Blockchain.

Um es zu erstellen, rufen wir die build_block()Methode auf und geben ihr einige Standardwerte. Die Parameter proof_numberund previous_hasherhalten beide den Wert Null, Sie können ihnen jedoch jeden beliebigen Wert zuweisen.

Hier ist der Code:

def build_genesis(self):
        self.build_block(proof_number=0, previous_hash=0)
 def build_block(self, proof_number, previous_hash):
        block = Block(
            index=len(self.chain),
            proof_number=proof_number,
            previous_hash=previous_hash,
            data=self.current_data
        )
        self.current_data = []  
        self.chain.append(block)
        return block

Bestätigung der Gültigkeit der Blockchain

Die confirm_validityMethode ist entscheidend, um die Integrität der Blockchain zu überprüfen und sicherzustellen, dass Inkonsistenzen fehlen.

Wie bereits erwähnt, sind Hashes von entscheidender Bedeutung für die Realisierung der Sicherheit der Kryptowährungs-Blockchain, da jede geringfügige Änderung an einem Objekt zur Erstellung eines völlig anderen Hashs führt.

Somit verwendet das confirm_validityVerfahren eine Reihe von if-Anweisungen, um zu beurteilen, ob der Hash jedes Blocks kompromittiert wurde.

Darüber hinaus vergleicht es auch die Hash-Werte von jeweils zwei aufeinanderfolgenden Blöcken, um Anomalien zu identifizieren. Wenn die Kette richtig funktioniert, gibt sie true zurück; Andernfalls wird false zurückgegeben.

Hier ist der Code:

def confirm_validity(block, previous_block):
        if previous_block.index + 1 != block.index:
            return False
        elif previous_block.compute_hash != block.previous_hash:
            return False
        elif block.timestamp <= previous_block.timestamp:
            return False
        return True

Deklarieren von Transaktionsdaten

Die get_dataMethode ist wichtig, um die Daten von Transaktionen in einem Block zu deklarieren. Diese Methode verwendet drei Parameter (Absenderinformationen, Empfängerinformationen und Betrag) und fügt die Transaktionsdaten zur Liste self.current_data hinzu.

Hier ist der Code:

def get_data(self, sender, receiver, amount):
        self.current_data.append({
            'sender': sender,
            'receiver': receiver,
            'amount': amount
        })
        return True

Bewirken des Arbeitsnachweises

In der Blockchain-Technologie bezieht sich Proof of Work (PoW) auf die Komplexität, die mit dem Mining oder der Generierung neuer Blöcke auf der Blockchain verbunden ist.

Zum Beispiel kann das PoW implementiert werden, indem eine Zahl identifiziert wird, die ein Problem löst, wenn ein Benutzer eine Rechenarbeit abschließt. Jeder im Blockchain-Netzwerk sollte den Zahlenkomplex identifizieren, aber leicht zu überprüfen finden – dies ist das Hauptkonzept von PoW.

Auf diese Weise verhindert es Spam und gefährdet die Integrität des Netzwerks.

In diesem Artikel veranschaulichen wir, wie Sie einen Proof of Work-Algorithmus in ein Blockchain-Kryptowährungsprojekt einbinden.

Abschluss mit dem letzten Block

Schließlich wird die Hilfsmethode Latest_block() verwendet, um den letzten Block im Netzwerk abzurufen, der tatsächlich der aktuelle Block ist.

Hier ist der Code:

def latest_block(self):
        return self.chain[-1]

Implementieren von Blockchain-Mining

Das ist jetzt der spannendste Abschnitt!

Anfänglich werden die Transaktionen in einer Liste nicht verifizierter Transaktionen geführt. Mining bezieht sich auf den Prozess, die ungeprüften Transaktionen in einen Block zu legen und das PoW-Problem zu lösen. Es kann als die Rechenarbeit bezeichnet werden, die bei der Überprüfung der Transaktionen beteiligt ist.

Wenn alles richtig herausgefunden wurde, wird ein Block erstellt oder abgebaut und mit den anderen in der Blockchain zusammengefügt. Wenn Benutzer einen Block erfolgreich abgebaut haben, werden sie oft dafür belohnt, dass sie ihre Computerressourcen zur Lösung des PoW-Problems verwenden.

Hier ist die Mining-Methode in diesem einfachen Kryptowährungs-Blockchain-Projekt:

def block_mining(self, details_miner):
            self.get_data(
            sender="0", #it implies that this node has created a new block
            receiver=details_miner,
            quantity=1, #creating a new block (or identifying the proof number) is awarded with 1
        )
        last_block = self.latest_block
        last_proof_number = last_block.proof_number
        proof_number = self.proof_of_work(last_proof_number)
        last_hash = last_block.compute_hash
        block = self.build_block(proof_number, last_hash)
        return vars(block)

Zusammenfassung

Hier ist der gesamte Code für unsere Krypto-Blockchain-Klasse in Python:

import hashlib
import time
class Block(object):
    def __init__(self, index, proof_number, previous_hash, data, timestamp=None):
        self.index = index
        self.proof_number = proof_number
        self.previous_hash = previous_hash
        self.data = data
        self.timestamp = timestamp or time.time()
    @property
    def compute_hash(self):
        string_block = "{}{}{}{}{}".format(self.index, self.proof_number, self.previous_hash, self.data, self.timestamp)
        return hashlib.sha256(string_block.encode()).hexdigest()
    def __repr__(self):
        return "{} - {} - {} - {} - {}".format(self.index, self.proof_number, self.previous_hash, self.data, self.timestamp)
class BlockChain(object):
    def __init__(self):
        self.chain = []
        self.current_data = []
        self.nodes = set()
        self.build_genesis()
    def build_genesis(self):
        self.build_block(proof_number=0, previous_hash=0)
    def build_block(self, proof_number, previous_hash):
        block = Block(
            index=len(self.chain),
            proof_number=proof_number,
            previous_hash=previous_hash,
            data=self.current_data
        )
        self.current_data = []  
        self.chain.append(block)
        return block
    @staticmethod
    def confirm_validity(block, previous_block):
        if previous_block.index + 1 != block.index:
            return False
        elif previous_block.compute_hash != block.previous_hash:
            return False
        elif block.timestamp <= previous_block.timestamp:
            return False
        return True
    def get_data(self, sender, receiver, amount):
        self.current_data.append({
            'sender': sender,
            'receiver': receiver,
            'amount': amount
        })
        return True        
    @staticmethod
    def proof_of_work(last_proof):
        pass
    @property
    def latest_block(self):
        return self.chain[-1]
    def chain_validity(self):
        pass        
    def block_mining(self, details_miner):       
        self.get_data(
            sender="0", #it implies that this node has created a new block
            receiver=details_miner,
            quantity=1, #creating a new block (or identifying the proof number) is awared with 1
        )
        last_block = self.latest_block
        last_proof_number = last_block.proof_number
        proof_number = self.proof_of_work(last_proof_number)
        last_hash = last_block.compute_hash
        block = self.build_block(proof_number, last_hash)
        return vars(block)  
    def create_node(self, address):
        self.nodes.add(address)
        return True
    @staticmethod
    def get_block_object(block_data):        
        return Block(
            block_data['index'],
            block_data['proof_number'],
            block_data['previous_hash'],
            block_data['data'],
            timestamp=block_data['timestamp']
        )
blockchain = BlockChain()
print("GET READY MINING ABOUT TO START")
print(blockchain.chain)
last_block = blockchain.latest_block
last_proof_number = last_block.proof_number
proof_number = blockchain.proof_of_work(last_proof_number)
blockchain.get_data(
    sender="0", #this means that this node has constructed another block
    receiver="LiveEdu.tv", 
    amount=1, #building a new block (or figuring out the proof number) is awarded with 1
)
last_hash = last_block.compute_hash
block = blockchain.build_block(proof_number, last_hash)
print("WOW, MINING HAS BEEN SUCCESSFUL!")
print(blockchain.chain)

Lassen Sie uns nun versuchen, unseren Code auszuführen, um zu sehen, ob wir einige digitale Münzen generieren können ...

Wow, es hat funktioniert!

Abschluss

Das ist es!

Wir hoffen, dass dieser Artikel Ihnen geholfen hat, die zugrunde liegende Technologie zu verstehen, die Kryptowährungen wie Bitcoin und Ethereum antreibt.

Wir haben gerade die Grundideen veranschaulicht, um Ihre Füße in der innovativen Blockchain-Technologie nass zu machen. Das obige Projekt kann noch verbessert werden, indem andere Funktionen integriert werden, um es nützlicher und robuster zu machen.