. But what does it mean in concrete terms? Well, to understand it, let's look at the term "

A fungible good is simply a good that can be replaced by another one, which is of the same nature and quantity. Thus, 

 are fungible: if you exchange 5 euros for 5 other euros, even though the coins may be different, the value exchanged remains the same.

Now, a non-fungible good: it is a good that is unique, and irreplaceable. For example, a work of art is non-fungible: even though 2 paintings may share certain characteristics (canvas, paint used...), 2 given works are totally different!

Thus, you will have understood: an NFT is a 

. Thus, NFTs can be declined in different forms: artworks, digital pass, collectible game card... see by yourself :

 is a digital artwork created by the artist Liam Pitchford.

 is a digital pass that allows the holder a lot of exclusivities, including free seats to NBA games.

You know the Pokemon cards? Here is the equivalent in digital format, but for football! Sorare is a collectible card game, based on NFTs.

That's a good question! What is the difference between an NFT and a normal image for example? Why do we suddenly go crazy buying images when we can view them for free?

First of all, what is the difference between an NFT and an image? In fact, not much: both are digital, we can save them in our files... in short, no revolution in itself. Except that an NFT is above all an 

 to which one attaches an image, a video, a music... digital content. And this deed of ownership is 

, any action carried out on the blockchain is verifiable by everyone. So, if you buy an NFT today, everyone would see it and no one could dispute its 

, since NFTs are based on the blockchain.

And that's why NFTs have become so valuable: for the first time, on the internet, you can certify that you 

. And so, like any new technology, NFTs have rapidly gained value, because they only respond to the laws of the market: supply and demand.

The most expensive NFT in history was created by Mike Winkelmann, known as Beeple. The work, entitled Everydays: The First 5000 Days, is a collage of 5,000 works created daily by the artist. It was sold by auction, for the modest sum of 69.3 million dollars. Only that!

Although it can be very expensive, an NFT can have many different case uses: we have seen some of them above.

Concretely, to understand the extent of NFTs and their usefulness, you have to remember that an NFT is mainly a 

 or even physical good. Thus, we can have many different applications:

. We can now certify that such work belongs to such person, whether it is paintings, videos, music...

And thanks to this, artists have much more freedom: instead of going through third party platforms to publish their content that doesn't really belong to them anymore, with NFTs they can manage their art and the monetization linked to it in the way they want.

Video games can be a very good application: the most profitable games are those based on 

When you buy a skin on Fortnite, you can't resell it if you don't want it anymore... but NFTs make it easy to transfer the skin from one account to another, and this in a transparent way.

The luxury sector could benefit from NFTs: indeed, NFTs could allow to certify the origin of a physical good. 

Thus, luxury brands could avoid counterfeiting by selling with their product an NFT that traces the entire production chain, as well as the actual owner of the product.

In this way, one would be certain of the origin of the product, as well as its owner.

Thanks to NFTs, it would be easier to record the acquisition of a property, or even create leases.

Thus, by linking NFTs and crypto-currencies, one could directly buy a home (and its associated NFT) with crypto-currencies.

One could even make a lease that is automatically broken in case of unpaid rent.

Thanks for reading ! If you liked this kind of article which is easy to understand, you can read a few more in french on 

 ! Or just wait a bit till the rest is posted on 

Hachage

The NFTs (for dummies)

, don't hesitate to do so! Indeed, some of the concepts explained in this tutorial require some pre-requisites, which you can find in these articles.

As the name suggests, it's simply a wallet for crypto-assets, or crypto-currencies. With a wallet, you can manage your funds as you see fit: receive, send, buy crypto-currency. Generally speaking, a crypto wallet allows you to 

So there are several solutions available to you. In fact, there are 2 categories of crypto wallet management:

A custodial wallet is a wallet that you do not own directly, i.e. you 

do not have control over the private keys

 associated with it, and therefore over the "password" of your wallet. These are managed indirectly by the platform that manages your wallet.

A non-custodial wallet is a wallet that you 

: you alone are responsible for it, and there is no intermediary who manages this portfolio.

In addition, for non-custodial wallets, it is important to note that there are 

. In short, these are objects that are similar to USB keys or hard disks, and that will have as a unique function to manage your crypto-currencies.

A Ledger : USB-key for crypto-currencies !

Moreover, they have the advantage of being 

: it will be much more difficult (or even impossible) to hack your physical wallet if it is not connected to any device!

Now that you have understood that, I propose you to see a comparison of the solutions that exist! They are all widely used, have their pros as well as their cons, and they are all available in English as well as on mobile (iOS and Android).

Note that none of those exchanges are affiliate : the ranking displayed below is based on the volume exchanged in the last 24h. (based on 

Note that the ranking below is only based on my personal thoughts and user experience. And once again, I'm not affiliate with any of those !

You now have your wallet: great! But a wallet without funds is not very useful... so, if you want to buy crypto-currency, feel free to 

look directly into the wallet you are using

: every option listed above offers crypto-currency purchase.

If it's still unclear to you, no worries! We will write an article very soon to guide you through your purchase, explaining well the risks and mistakes not to make.

Create your own crypto wallet !

These are often the kinds of questions that everyone is asking about crypto-currencies. Indeed, since the birth of Bitcoin in 2009, there have been many differing opinions regarding this new financial asset. Some will say it's been a scam from the start, while others have invested a lot of their time and money in this new eco-system.

But then: Who is right? Who is wrong? We'll see right now by trying to understand the 2 parties!

First, let's start by understanding why it might be a scam. There are several reasons for this:

Disruptive novelty and lack of confidence

Bitcoin arrived in 2009, and it wasn't until later that it was taken seriously. And in fact, if you notice, we've already experienced exactly the same thing with the beginnings of the Internet: born in 1989, we only started to use it years later, with the advent of the web in the 2000s.

And whether it's the Internet or Bitcoin, because it's new, we don't know how to use it and so for many people it's something dangerous.

Look at this video from the NBC about the e-mails: 

You will notice that if you do the same kind of TV show with guests talking about Bitcoin today, the answers will probably be as vague as those given in the video. And yet, the e-mails is used a lot nowadays! 

Since 2009, many unscrupulous people have successfully scammed or hacked many victims. Here is a short history:

MT.Gox was a centralized exchange, that is to say a platform where you could exchange money (dollars, euros...) for crypto-currencies. At its peak, 70% of bitcoins were exchanged on this platform... but unfortunately hackers stole a large part of the bitcoins, which will cause the bankruptcy of the company in February 2014.

Bitconnect was a company that promised very high rates of return, thanks to a very efficient "trading robot". Unfortunately, this was not the case: their business was based on a Ponzi pyramid: it is a fraudulent financial system where the remuneration of investors comes from the investments of the entrants. The company created in 2016 then fell in 2018 because of this.

TheDAO was, on a paper, a good idea: it is a decentralized investment fund. (DAO stands for Decentralized Anonymous Organisation). But unfortunately, a large part of the funds have been stolen following a hack. We are talking about several million dollars!

Seeing all this, one wonders if investing in crypto-currencies or blockchain technology in general is really a good idea... Let's see now the point of view of "crypto-enthusiasts".

A payment system that can be used by everyone

, anyone can use crypto-currencies as long as they have access to the internet, either via a phone or a computer. In addition to that, there are plenty of different crypto-currencies that can be traded, including so-called stable currencies that are based on the dollar or the euro.

In fact, it is even those crypto-currencies that are based on the dollar that are 

. For example, dollar-based crypto-currencies have recorded a trading volume of about 

And in fact, it will surely be used more and more as a means of payment in the years to come:

When you take a closer look, an international bank transfer takes days to make, has quite high fees, and you need a bank to do it. And this is not for everyone when you know that about 

Today, it is no longer just about crypto-currencies, but about projects centered around blockchain technology. 

In fact, since 2015 thanks to the Ethereum blockchain, it is possible to create decentralized programs. So to speak, these are smart contracts that are not governed by humans, but by machines. How does it work in practice? Well, smart contracts work 24 hours a day and are governed by the law of programming. Thus, there can be several applications:

And these are only a few examples among the many possibilities that are offered. Besides, all this was possible before, but now we remove trusted third parties (banks, centralized databases like Google, etc...) to fully recover our rights and data.

This new technology undoubtedly offers us many possibilities, but unfortunately some people will not hesitate to use the inadvertence of users to profit with well-prepared scams. In fact, this is certainly a security issue:

The actions one performs on the blockchain cannot be undone.

Indeed: if you ever make a mistake in a bank transfer, you can call your bank and cancel it. But here, it is you and you alone who are the owner of your funds, and you must assume the consequences.

Crypto-currencies : scam or future ?

, it is important to know how to use them and especially to protect them. Indeed, as you will have understood, one of the particularities of crypto-assets is that when you make a transaction, it is irreversible: there will be no one to call to recover your funds!

This is what makes both the strength (no one manages your money: 

 are responsible for it) and the weakness of crypto-currencies.

 works, let's make the comparison with what you know: your bank account!

The key characteristics of a bank account are:

You send it whenever you want to receive money. For example:

: you can share it with people/companies to get paid.

They are private and belong to you. You must not share them. In general, they consist of a login and a password. For example:

The key characteristics of a crypto-wallet are:

You send it whenever you want to receive money. For exemple:

bc1q63kr2qx4z9xvvxwmr086uj0ql0tfffnv2rxz9n

: you can share it with people or companies to get paid.

It is private and belongs to you. You must not share it. This key is linked to your public key. It is a unique identifier. For example:

503b8b03a0f21bc2580d6b9e7983960acb324b7adf8c139874a609d760662d5d

A private key is a number generated between 1 and 2^256 possibilities, that is 10^77 possibilities. In other words, it is statistically impossible to generate an already existing private key. To give you an idea, a deck of 52 cards can be shuffled in 10^68 different ways... and yet, right now if you do a shuffle, you're pretty much guaranteed to create one that has never been done before!

So you'll understand: having a crypto-currency wallet is like having a bank account! Except that here, you are the only manager of it. We'll learn together how to create your first crypto-currency wallet, but first, feel free to read on!

Whether it's on TV or on social media, we often hear that crypto-currencies are scams. This is partly true... but not because of the technology, but because of its users!

In fact, just like the Internet, crypto-currencies can have very good uses as well as bad ones, and unfortunately scams are one of them. In fact, since crypto-currency transactions are 

get scammed without being able to get your money back

 without intermediaries, is not a scam. On the other hand, some malicious actors who promise you 

 in exchange for your currencies... they clearly want to scam you!

As we have just seen, if you lose your crypto-currencies it's because you are being scammed, and very often it's because you are misinformed on the subject!

So, to avoid getting scammed with crypto-currencies as much as possible, here are 3 rules (among many others!) that are very important to respect.

Would you share your bank details? Never! Well, it's exactly the same for a private key to a crypto-currency wallet. You should absolutely keep your private key to yourself. More often than not, unsuspecting users share their keys on fraudulent sites, which pretend to be official sites... so you have to be careful at all times.

This rule is especially true for any investment in general. At the moment, crypto-currencies are extremely volatile for many of them: for example, 1 Bitcoin can be worth $30,000 today and $10,000 tomorrow. If you bought one today, you would have lost $20,000!

In the blockchain world, thousands of projects are born every year. Some of them are very interesting, while others are just selling a dream: it is important to understand the subtleties of the projects before investing in them.

How to secure your digital assets (for dummies)

So a crypto-currency is the combination of 2 words: 

. As you've understood, a crypto-currency is therefore money that uses the principles of cryptography to be exchanged.

It's a highly volatile asset, but not only that !

It is a way to exchange messages or more generally data in a confidential and secure way.

It is a unit of value that is standardized so that everyone can exchange goods and services more easily.

Even though the terms are defined, it doesn't necessarily help you understand the craze behind crypto-currencies? I'm getting to that!

So, if we go back to the terms, a currency is a unit of value that everyone exchanges, but it is based on one very important thing: 

. Indeed, at the moment, when we exchange bills, or even when we make transfers, we just exchange "numbers". 

Until 1971, the US dollar was exchangeable for gold, and therefore indirectly all currencies were exchangeable for gold and therefore based on gold as a value. This is no longer the case today: money is only based on the value we give it!

In addition to being able to exchange messages in a confidential way, cryptography allows above all to have 

 in the messages sent. As explained briefly in the chapter on the 

: this means associating a piece of data with a unique fingerprint that can be verified by everyone. So this process allows to detect if the message has been modified between sending and receiving.

 word hashed (with the SHA256 algorithm):

. You'll notice that we just added an r, and yet the hash has completely changed:

The famous Bitcoin represented under a coin.

, by a developer (or collective of developers) by the name of 

. To this day, no one knows who is behind this alias! And yet, since the launch of Bitcoin, Satoshi has only one idea in mind: to create a digital currency independent of banks and institutions. And to do this he describes his whole idea in an 

) that explains in detail how his new currency works.

To summarize, this whitepaper explains in more detail how a crypto-currency works, and in this case Bitcoin.

It explains how payments are handled, and answers some of the issues that might arise in a peer-to-peer payment system (the issues being partially answered with what you've read in the parts above!)

The document is very complete and very interesting, so don't hesitate to have a look at it if you ever have the time and will!

The Bitcoin's whitepaper : interesting but technical !

🪙 21 million units, of which 19 million are currently in circulation

😱 Record number of transactions: 490,644 on December 14, 2017

⚙️ 1.60$ transaction fee at the moment.

*: this price was estimated following the first transaction made with bitcoin: the purchase of 2 pizzas! On May 22, 2010, one Bitcoin user bought 2 pizzas from another user for the modest sum of 

! At the time, it wasn't worth much... But today, those 10,000 bitcoins (and therefore the 2 pizzas) are worth 

The crypto-currencies (for dummies)

A word that seems quite complicated... but the principle is simple to understand!

We will detail all this point by point, no worries.

Here's what a database looks like. Quite frightening!

By the way, what is a database? It's a place where you 

, as simple as that. You certainly know some: you use them even every day without realizing it. 

When you do a search on Google for example, a lot of servers are going to be activated to deliver the result of your search to your computer. But, to do this, Google is 

obliged to store data related to your search on their servers

, which belong to them and are therefore centralized.

But the blockchain is not centralized. It is therefore:

: these 3 notions (decentralization, transparency and security) are not a standard and some cases are exceptions.

In addition to all this, a blockchain has 2 particularities: 

That the blockchain is immutable: you can't change its content, only add data. And to be sure that everyone respects this, the 

 (between blocks) is very important: since each block is linked, changing one would change everything. 

 which allows each block to have a unique identifier, and if you change just a little bit the content of a block, then its unique identifier changes completely.

The first use case, which is the best known: 

. Indeed, as long as you can add data on a blockchain, you can add transactions, for example with Bitcoin. Thus, Bitcoin is neither more nor less than a giant ledger where all transactions are recorded from the beginning!

This coin doesn't really exists, Bitcoin is a digital currency !

Thus, the characteristics of the blockchain make sense for crypto-currencies:

, currencies are exchanged directly from peer-to-peer without an intermediary, such as a bank for example. As it is 

, each individual can verify that person A has paid person B. And finally, since it is secure, we can be sure that nobody will be able to create money from nowhere, or make a 

 (make a payment that 2 people will receive).

In fact, we can do a lot of things with blockchain: we can exchange information peer-to-peer easily and safely. If we start from this principle, we can imagine a platform like E-bay but applied to virtual properties: we could exchange video games, movies, art... and this without getting ripped off, either for the seller or the buyer. By the way, speaking of art, NFTs seem to be a good practical case.