Hii 👋,

I’m Arnab Sen

Computer Programmer interested in Information Security, DevOps & Open Source. Loves to participate in CTFs and Competitive Coding.

Digging IsStandard in Bitcoin Core

Digging IsStandard in Bitcoin Core

Here, we will focus more on the Bitcoin Core implementation of the different types of scripts / transactions methods. Here is the repo. Standard Types There is an enum class called TxoutType that lists all the possible types of TxOut i.e Output Transaction. src/script/standard.h#L59-L71 An enumeration is a user-defined type that consists of a set of named integral constants that are known as enumerators. In this case, any instance of the TxoutType can be either of those mentioned values....

August 15, 2021 · 8 min · Arnab Sen
Overview of Script

Overview of Script

Context We know the bitcoin ledger is nothing but a Blockchain. And a single entity of the blockchain is called Block. A block is a container data structure that aggregates transactions for inclusion in the public ledger, the blockchain. Fig: The blocks in the Block chain and one block waiting to be mined. Image Source: https://mempool.space/ The structure of a block Size Field Description 4 bytes Block Size The size of the block, in bytes, following this field 80 bytes Block Header Several fields form the block header 1–9 bytes (VarInt) Transaction Counter How many transactions follow Variable Transactions The transactions recorded in this block So each block has some transactions....

August 15, 2021 · 7 min · Arnab Sen
Merkle Trees

Merkle Trees and it's role in decentralised web

Merkle Trees Centralised Web How does the web in general work? Usually, we have a server where we upload files, and then we can access those files from some other nodes connected to the network the server is connected to. For example, if you want to host your videos for people to watch, you would rather choose Youtube or Google Drive or similar hosting/file-sharing services. Now, this is very convenient because a user doesn’t have to maintain those services or manage them....

July 13, 2021 · 7 min · Arnab Sen
Hello World! in Rescript-React

Hello World! in Rescript-React

Hello World! in Rescript React Talking a bit about Rescript, it is a new language that combines the best parts of JS and OCaml. It has a compiler that compiles to JS and leverages OCaml’s static and sound type system. Many people prefer this approach to TypeScript. The compiler was originally named BuckleScript but in 2020, it was rebranded to ReScript because of its Reason-like syntax. Rescript docs are well written, organized, and maintained actively....

March 5, 2021 · 6 min · Arnab Sen
Modules and Libraries in C

Modules and Static Libraries in C

Modules and Libraries in C Usually, for smaller programs, we always write one source file, compile and run it. But for a big codebase, we would rather prefer to have a modular approach. It means we would group statements which does similar work under one file and import those into the main source file. This is called modular programming. According to Wikipedia: Modular programming is a software design technique that emphasizes separating the functionality of a program into independent, interchangeable modules, such that each contains everything necessary to execute only one aspect of the desired functionality....

February 15, 2021 · 8 min · Arnab Sen