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Monday, April 02, 2018

Bitcoin Address Generation : The Internals Behind

ECDSA stands for Elliptic Curve Digital Signature Algorithm and uses an elliptic curve and a finite field to "sign" data in such a way that third parties can verify the authenticity of the signature while the signer retains the exclusive ability to create the signature. The Bitcoin addressing system is not a simple deal.In order to maintain that a public key cannot be deciphered easily to any identity and in future if ECDSA is compromised at all, still,the anonymity remains.So suppose you have a ECDSA based private key,the following post content will give a step by step sequence of how the final bitcoin address is derived :
Sequence flow chart is shown below :

Image courtesy : https://www.safaribooksonline.com/library/view/mastering-bitcoin-2nd/9781491954379/assets/mbc2_0405.png

Your sample private key :

18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725

Public key derived is 

0450863AD64A87AE8A2FE83C1AF1A8403CB53F53E486D8511DAD8A04887E5B2
3522CD470243453A299FA9E77237716103ABC11A1DF38855ED6F2EE187E9C582
BA6

Site reference : https://www.bitaddress.org

Screen shot below : 

 Now perform SHA-256 hashing on the hex of the public key as shown below in the screenshot :

The SHA-256 output received is 

600ffe422b4e00731a59557a5cca46cc183944191006324a447bdb2d98d4b408

Now we take RIPEMD-160 Hash of the above output and get this as follows as seen vide the screenshot :

010966776006953d5567439e5e39f86a0d273bee

Now add Add version byte in front of RIPEMD-160 hash (0x00 for Main Network).so that the above output becomes :


00010966776006953D5567439E5E39F86A0D273BEE

Further to above,Perform SHA-256 hash on the extended RIPEMD-160 result ie

 
 so we get
445c7a8007a93d8733188288bb320a8fe2debd2ae1b47f0f50bc10bae845c094

and now we perform SHA-256 hash on the result of the this recent SHA-256 hash as seen below in the screenshot...and we get this as 

d61967f63c7dd183914a4ae452c9f6ad5d462ce3d277798075b107615c1a8a30


Now take the first 4 bytes of the second SHA-256 hash and this is the address checksum ie D61967F6

and then add the 4 checksum bytes at the end of extended RIPEMD-160 hash as hashed above and we get the 25-byte binary Bitcoin Address.

00010966776006953D5567439E5E39F86A0D273BEED61967F6

Now the last step...we  Convert the result from a byte string into a base58 string using Base58Check encoding at https://incoherency.co.uk/base58/

 Bitcoin Address : 
16UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM

Useful links : 

Friday, March 30, 2018

Compiling Bitcoin Core Source Code : Ubuntu 16.04 LTS


1.   Bitcoin Core is the reference implementation of bitcoin and anyone ON with any projects around bitcoin would need to compile the bitcoin source code to create the bitcoind for his/her own node. Ubuntu is usually the operating system recommended to run Bitcoin Core.This post will build upon with screenshots as done and terminal commands as executed to compile the same vide GIT.

2.  The machine I have used here is a Ubuntu 64 bit running on a virtual box platform with the following details as seen in the screenshot :

Now on I will just share the terminal commands as i executed in the terminal :

sudo apt-get update

sudo apt-get upgrade


sudo apt-get install git


Search for Bitcoin github and click the first link as seen below :


Goto the link as seen below at https://github.com/bitcoin/bitcoin/blob/master/doc/build-unix.md


sudo git clone https://github.com/bitcoin/bitcoin.git



sudo apt-get install build-essential libtool autotools-dev automake pkg-config libssl-dev libevent-dev bsdmainutils python3


sudo apt-get install libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-program-options-dev libboost-test-dev libboost-thread-dev



sudo apt-get install libboost-all-dev


sudo apt-get install software-properties-common


sudo add-apt-repository ppa:bitcoin/bitcoin


sudo apt-get update


sudo apt-get install libdb4.8-dev libdb4.8++-dev


sudo apt-get install libminiupnpc-dev


sudo apt-get install libzmq3-dev


sudo apt-get install libqt5gui5 libqt5core5a libqt5dbus5 qttools5-dev qttools5-dev-tools libprotobuf-dev protobuf-compiler



sudo apt-get install libqrencode-dev


sudo ./autogen.sh



sudo ./configure --disable-wallet #


sudo make

and the last command

sudo make install


....and you r ready to go.....

Saturday, March 24, 2018

The MIST Browser : Installation UBUNTU 16.04 LTS

Mist Browser (formerly Ethereum Dapp Browser) is the end-user interface for Ethereum. It's the tool of choice for browsing and using Dapps and is specifically designed for non-technical users.The following post shows a series of screen shots to install the same on UBUNTU 16.04 LTS.Zoom in the screen shots to see the details as desired please. Link at
https://github.com/ethereum/mist/releases
  













Monday, March 19, 2018

BLOCKCHAIN ,BITCOIN & CRYPTOCURRENCIES WORLD : MECHANICS AND CYBER CRIME

The world of Blockchain and Cryptocurrencies is undeniably amazing and has infinity to explore at hands.Recently I took on a 4 hour session at the prestigious Central Bureau of Investigations,CBI Academy ,Ghaziabad, vide Indian Technical and Economic Cooperation Programme organised by Ministry of External Affairs,to cover right from scratch to overview of mechanics and architecture of how this world works.Sharing here the presentation for info and awareness of anyone who is interested to take a dip in this domain and related cyber crime activities.


Sunday, February 25, 2018

Symposium on Legal Regulation of Bitcoin, Blockchain & Cryptocurrencies

On 22nd Feb, participated in Symposium on Legal Regulation of Bitcoin, Blockchain & Cryptocurrencies held at G D Goenka University,Sohna Road.I was privileged to meet Joerg Molt from the Satoshi School.Sharing my presentation here for info of readers.


and few pics of event below