How to secure a marketplace where you could buy and sell digital goods when the blockchain is public ?
How to exchange and encrypt private keys on the blockchain? A decentralized marketplace example.
Guillaume Grandjean - 2024-02-11

While scrolling and reading some articles on Google News, I told myself what a great tool is that all is gathered in one place for the users. No need to crawl the internet, to find information or news! But as always centralisation has also its downside. This platform aims to empower the so much Google against the publishers, that it has become an inevitable source of tension with the revenue generated by the ads. What if the blockchain could help to promote, share, and distribute public and/or private content? This idea led me to propose a concept of a decentralized marketplace where authors could publish and sell their content.

Image 1: An NFT contains metadata, how can we easily access it?
How to access your NFT? A Web2 approach using the best APIs
Guillaume Grandjean - 2022-12-23
Practical example

With an estimated market of more than 11 billion dollars, NFTs are becoming more and more mainstream and widely used. Many applications are developed around them. However, there are different ways to interact with them, some more complicated than others. In this article, we will explain the different ways to retrieve metadata from an NFT. We will detail the “Web 2” approach by comparing different services offering a programming interface (API) for NFTs on the Ethereum Blockchain. Then, we will present an actual example showing how to use these services with an Android and iOS application.

“ According to, there are more than ten thousand different cryptocurrencies.”
The different cryptocurrencies categories 
Leonardo Gomez Mariaca - 2022-11-15
Primary Concept

In our last article, we interested ourselves in the concrete application that Blockchain technologies could offer. We also evoked VeChain, a cryptocurrency notably used for asset traceability. Today, we are going to take the thought further, by looking at the different exciting cryptocurrencies on the market.

« The trust machine », The Economist, 2015.
Blockchain applications
Leonardo Gomez Mariaca - 2022-10-25
Primary Concept

In our previous article, we were interested in the notion of smart contracts and their concrete applications. Today, we will push the thinking a bit further and interest ourselves in the different uses and services that could result from the usage of blockchain technology.

Contract: Legally enforceable convention whereby one or many peoples have to give, do or not do something for someone else.
The smart contracts
Leonardo Gomez Mariaca - 2022-10-10
Primary Concept

In our previous article, we were interested in the security of a decentralized system. Today, we are going to look at one of the first concrete use cases of the blockchain with smart contracts.

Celsius Network filed for Chapter 11 bankruptcy on July 13th, 2022
What happened to Celsius Network? How to get your funds back?
Amaury Wei - 2022-08-14

As you might not have heard in the mainstream news, multiple major cryptocurrency entities have recently filed for bankruptcy. These include two of the biggest industry names: Voyager Digital LLC, a crypto broker; and Celsius Network LLC, a lending platform.