Bitcoin with C#

In this tutorial, we are going to introduce Bitcoin using C#. We will be using C#’s bitcoin library, called NBitcoin.

Install Nbitcoin

dotnet add package NBitcoin

Generate a private key

A private key in the context of Bitcoin is a secret number that allows bitcoins to be spent. Every Bitcoin wallet contains one or more private keys.

This is how you generate a private key with NBitcoin:

var privateKey = new Key();
var bitcoinPrivateKey = privateKey.GetWif(Network.Main).ToString();
Console.WriteLine(bitcoinPrivateKey);
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Generate a public key

var privateKey = new Key();
var bitcoinPrivateKey = privateKey.GetWif(Network.Main);
var bitcoinPublicKey = bitcoinPrivateKey.PubKey.ToString();
Console.WriteLine(bitcoinPublicKey);
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Create a Bitcoin address

You know that your Bitcoin Address is what you share to the world to get paid.

var privateKey = new Key();
var bitcoinPrivateKey = privateKey.GetWif(Network.Main);
var bitcoinPublicKey = bitcoinPrivateKey.PubKey;
var address = bitcoinPublicKey.GetAddress(ScriptPubKeyType.Segwit, Network.Main);
Console.WriteLine(address);

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Generate Address from a known private key

var key = "L1TmYw2edTAyF9CtSF64k2Qc3AkKa8t9xn1vMa92xCe9VCzTbYzV";
var bitcoinSecret = new BitcoinSecret(key);
var address = bitcoinSecret.PubKey.GetAddress(ScriptPubKeyType.Segwit,Network.Main);
Console.WriteLine(address);
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Generate Mnemonic

A mnemonic recovery phrase or bitcoin seed is a list of words which store all the information needed to recover a bitcoin wallet

var mnemo = new Mnemonic(Wordlist.English, WordCount.Twelve);
//key victory fashion rough torch ice lesson main grape actual horn dinosaur

Generate Address from Mnemonic

var mnemo = new Mnemonic("dry brown drive parade drastic shine embrace hard report loan fold iron", Wordlist.English);
var hdroot = mnemo.DeriveExtKey();
var pKey = hdroot.Derive(new KeyPath("m/84'/0'/0'/0/0"));
var address = pKey.PrivateKey.PubKey.GetAddress(ScriptPubKeyType.Segwit, Network.Main));
Console.WriteLine(address);
//bc1qv7z69wxrew84vv43xrnfrckkzj4wzalf99e2cs

Generate Multiple Addresses from Mnemonic

Derivation path follows this convention:

m / purpose' / coin_type' / account' / change / address_index

So you can increase address_index from 0 to get new addresses from same mnemonic.

For more details: https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki

var mnemo = new Mnemonic("orange soup note oil token top slab elder mercy mad wool congress", Wordlist.English); 
var hdroot = mnemo.DeriveExtKey(); 
var pKey = hdroot.Derive(new KeyPath("m/84'/0'/0'/0/0")); 
var pKey2 = hdroot.Derive(new KeyPath("m/84'/0'/0'/0/1")); 
Console.WriteLine(pKey.PrivateKey.PubKey.GetAddress(ScriptPubKeyType.Segwit, Network.Main)); 
Console.WriteLine(pKey2.PrivateKey.PubKey.GetAddress(ScriptPubKeyType.Segwit, Network.Main));
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Conclusion

In this tutorial, we introduced bitcoin with c#. We saw how to generate a private key, public key, bitcoin address, mnemonic and also generate addresses from a mnemonic recovery phrase.

we talked about sending transaction in this post : https://medium.com/@vic_tha_god/sending-a-bitcoin-transaction-cf76aadf0a96

Source : https://programmingblockchain.gitbook.io/programmingblockchain/

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