There are a lot of wierd words used in Cardano as placeholders for different parts of the system. Of course, the world of blockchain is complicated, so some would say that using hard to remember and hard to spell words as well can make things a little confusing. Well, we're here to help. This is a short list of all the most commonly used words and phrases and a quick reminder of what they mean, with links where applicable. A great way to see an overview of the original plan is Charles' whiteboard from Oct 2017 - he says a lot of words in it.

Phases: The phases of the Cardano Project...

Byron (phase 1)

In the Byron phase the Cardano protocol is created and is supported by servers run by IOHK. At this point the only coin is ADA, and it runs a UTXO protocol. While new transactions are created by centralised servers anybody can install a Daedalus wallet which downloads and verifies the full blockchain. During this phase a lot of polishing goes into the way the blockchain is stored and the asthetics and speed of the experience. Little known fact: Lord Byron was the father of Ada Lovelace.

Shelley (phase 2)

In Shelley the new blocks are created by anyone who wants to create a staking pool and keep a server running 24/7. People who run pools advertise themselves in a master list and people who want to earn staking rewards delegate their staking option to the pool of their choice. The maths is worked out so that there is a good level of decentralisation.

Goguen (phase 3)

Here smart contracts are made available in the main net using a Universal Language Framework called IELE. This allows for flexibility when defining the rules in a smart contract in Cardano. There have been too many examples of hacked contracts allowing funds to be lost in other crypto-currencies, but there also needs to be enough power in the language to build complex contracts.
The solution is to provide multiple contract definition languages which all compile to a base language using a Universal Language Framework. The base language is Plutus, and is itself based on Haskell. Haskell is a good choice because it is a purely functional language and so can be mapped to a formal specification of intent. Compilers are then be developed that convert other languages into Plutus. Marlowe is the first example, which is a simplified language to define financial rules. Other languages, most notably Solidity will also be built.

Basho (phase 4)

In this phase the team will tackle the scalability problem which is a key area of concern in all blockchain projects. There is always a trade-off between speed, decentralisation and security. In highly decentalised systems it takes time for a transaction to propagate around the network, so reducing the block time or increasing the block size reduces security unless you cut the number of nodes. A new version of Ouroboros called Ouroboros Praos will be introduced, which will support multiple paralell blockchains, eventually allowing unlimited scalability.

Voltaire (phase 5)

In this phase the problem of governance and funding will be solved. One of the weak points of all crypto-currencies is the organisation that control it. These are the guys that write the software, and so decide how it will work, and also go out and market it, choose logos, set parameters, choose what the money will be spent on, etc. If power is concentrated in the hands of a few they can become lazy, or greedy. They can also disagree on the way forward, which leads to confusion or even a split in the whole community. If no power is given to anyone the system stagnates, nothing gets done.
In this final phase an automated, self-regulating, indestructible mechanism is created which allows a governing body to be elected and funded. It then allows that body to choose the direction of the system and scale according to need. It doesn't rely on individuals and has no single point of failure. It is built into the protocol.

Wallets: Most commonly used Cardano wallets...

Daedalus (full node wallet)

Daedalus is the name for the full node wallet. It downloads a full copy of the blockchain so you will need a bit of disk space to hold it and it will take some time to get synchronised. Sometimes its surprising how many people like to keep the whole blockchain and validate it themselves, but there is something nice about seeing it all work. When Shelly arrives you can stake your coins for a reward, and you can create multiple separate wallets with multiple addresses inside each wallet. It also supports a paper wallet, so once you are working you can create a new address which exists only on paper but can still be funded. Daedalus has been developed using Electron, which is a web based toolset using HTML, CSS, and JavaScript, but it runs locally, without a browser. You can download it for Windows, Mac, or Linux here.

Yoroi (light wallet)

Yoroi is an ADA only light wallet that runs as a Google Chrome extension, so it works with any browser which supports Chrome Extensions, such as Chrome or Firefox. The main things about it are that it is very easy to install, easy to use, and it supports Hardware Wallets like the Ledger Nano S. This is a very well known and commonly used hardware wallet, and its generally accepted that hardware wallets are the most secure way to hold your private keys. You can install Yoroi here

Exodus (easy to use multi-asset wallet)

Exodus is a great looking very easy to use multi-asset wallet that allows you to store your own private keys and hold lots of different currencies in one place. It supports all the ERC20 tokens as well as most of the major currencies, including ADA. For ADA as well as several other currencies it also supports staking, so with no extra hassle you get your rewards as well. It can also hold your NFTs, which is a great bonus. It doesn't allow you to trade them, but if you buy them in the wallet it will lock them until you want to transfer them out, then help you do it.

Exodus also supports the Trezor hardware wallet, and allows quick in-wallet swaps between currencies so if you have some Ether or Bitcoin (or anything really) you can quickly swap it for ADA. Overall, an excellent wallet choice. Download it here

Infinito (app for iPhone or Android)

Infinito is a fairly popular wallet for Android or Apple phones which supports a reasonable range of currencies including Cardano. There's no hardware wallet support, but the private keys are held in encrypted format on the local device so you are in control. You can also create friendly addresses in your address book, and they have a gateway to fiat (which I haven't tried). You can install Infinito from the Play store, or App store. The website is here

Atomic (universal wallet supporting lots of currencies)

Atomic advertises itself as a Universal Cryptocurrency Wallet and it supports lots of currencies. Apart from a long list of the major currencies you can also add any ERC20 token, so there is a good choice. You can choose the ones you want to show and hide the rest. You can also buy with fiat using a credit or debit card. Also atomic swaps from one currency to another work easily and quickly with a 2% fee. Its pretty good. It also works on a wide range of operating systems including Windows, Mac, Ubuntu, Debian, and Fedora. The website is here

Players: The primary players in the Cardano space...

IOHK (Software development)

IOHK is an achronym standing for Input Output Hong Kong. It is a company that was created at the start of everything by Charles Hoskinson and Jeremy Wood in 2015 after Charles left the Ethereum project and decided to create a new third generation technology which was launched as Cardano in September 2017. It may not sound like a great name for the power behind Cardano, since it is no longer based in Hong Kong, and its clearly about a lot more than IO, but Charles says it has far too much brand recognition now to change it, and he's in charge.
IOHK is the organisation which controls the research and develpment of the software that supports the whole Cardano ecosystem. They don't neccessarily write all the software, since they might work in pertnership with other organisations, but they co-ordinate the specification and development of all the technology, provide the roadmap, and verify the quality.

Emurgo (Solutions for businesses)

Emurgo are the organisation which help businesses to adopt Cardano as a solution. Some of this work is about marketing, so they would hope to help drive adoption, but its very hands on. They build solutions and give advice to organisations who have projects that need blockchain. They also manage training and eduction for people or organisations who want to learn. They have been going since June 2017. Find out more on their website.

Cardano Foundation (Community and market penetration)

The job of the Cardano Foundation is to spread the word. Some people would say this is the most important bit, because Cardano hasn't been going as long as a lot of the other currencies so its critical that the news gets out.
But there's a bit more to it than just advertising. First they deal with other blockchains like Ethereum and Hyperledger Fabric, building software and marketing themselves as a solution centre.
Second they work with the community of users and also with enterprises and governments to build software and legislation all over the world.
They also build commercial partnerships who want to build software, and build software themselves. They have developed web tools and apps which work as a front end to present featurtes to users, satisfying business needs, and linking to the blockchain at the back end.
The Foundation help build systems and show people what can be acheived, then bring people together to agree commercial and legal standards. By their efforts they hold the technical people who build the blockchain accountable for their decisions.

Projects: Cardano developed and planned projects...


Alonzo is the codename given to the hard fork which introduces Smart contracts into Cardano. Smart contracts are critical to the ecosystem, because they are the toolset which allow everything else to be built.
The alonzo hard fork is the first smart contract release for Cardano, as part of Plutus, and is named after Alonzo Church, the inventor of Lambda Calculus.

Native assets

Native assets on Ethereum can be created as tokens by coding the rules as a smart contract, but this is a complex process and can lead to bugs or shortcuts. Cardano, as a third generation blockchain, has built a toolset for generating native assets which have all the same attributes as ADA, including a (coming soon) plan to allow transaction fees to be paid in the native asset rather than ADA.


Atala is a framework, a bit like IBM's Hyperledger Fabric. A framework is a toolset, a list of utilities which have been created to do all the clever stuff and which are well tested. This makes it much easier for developers to build a new system because they just have to plug in the bits they need and they are off. Developers don't normally write all the code to do things. For example if you had a date field on the screen and wanted to offer a calendar to help enter it you wouldn't write all the code to render months and allow all the clicking and moving. That's been done, you just plug in a utility and use it.
Atala is a set of tools that are interoperable across blockchains to support a range of key functions needed by the builders of infrastructure that will link to blockchain technology. Key areas addressed are Identity, Payments and Supplychain. This will allow large projects to be built with complex data and rules managed off-chain, but hooked in for processing payments or running critical smart contracts which need to be trusted.
There is a focus on tools which would allow governments to build systems for use in their infrastructure such as registrations, deeds, licences, and local currencies. The first case is planned to be currency for Ethiopia, but pharmaceutricals in Mongolia is also rolling.


Seiza is a new blockchain explorer for Cardano. Blockchain explorers tend to be quite utilitarian in their approach, but this one is promised to be a bit more user friendly. Better looking and more accessible to people who maybe don't want to be faced with huge lists of digits and letters. At the time of writing its not here yet, so we have to wait.


Project Catalyst is at the centre of the Voltaire phase. It's purpose is to bring as many people as possible together into an effective decision making team to choose how to spend money to improve the ecosystem. When ada is generated during the creation of blocks a percentage (known as t) is kept back for the treasury. This then becomes available to spend on projects which allow the system to be developed then advertised to the world. Project Catalyst is the collaboration and voting system which has been created under the Ideascale umbrella to make effective generation and selection of ideas possible.


Polymesh is a collaboration between Cardano and Polymath, creating a bridge between the decentralised smart contracts in Cardano and the established regulatory framework offered by Polymath.
Polymath specialise in Security Token Offerings. The rules could be built into Cardano, but they are wide and varied because they depend on the laws of the countries of the world. It is faster, and more futureproof, to build a bridge to an established and well supported protocol which already has credibility and focus on the current legal frameworks than it is to start from fresh. Charles Hoskinson has the title of Co-architect at Polymesh.


Mithril is a project designed to allow users and systems to download and hold a reliable copy of the blockchain which is greatly reduced in size. In Cardano every transaction closes a list of UTXOs and creates new ones. The old transactions are marked as spent and can never be used again. This is in contrast to the account balance model, where balances go up and down. So, all the spent transactions only have value if you want to verify that a balance is real, by tracing backwards to its origin.
If you don't hold the blockchain you have to verify balances by asking someone you trust, and who holds the blockchain. Mithril is a third option. Download only the unspent transactions from someone you trust, then you can verify your own transactions. The Stakepool Operators keep a trusted copy of the blockchain and have something to lose if they cheat, so they can be used as a data source.
The Mithril project rewards Stakepool Operators for supplying snapshots of the UTXOs which are certified and stored in the Mithril Aggregator. That software can then supply the snapshots to wallets which can keep the balances up to date in real time.


QED is the very tentative title of a project to build a computer system that effectively represents all important mathematical knowledge and techniques. The QED system will conform to the highest standards of mathematical rigor, including the use of strict formality in the internal representation of knowledge and the use of mechanical methods to check proofs of the correctness of all entries in the system. Ambitiously, it intends to become a repository for all mathematical knowledge.


Smash stands for Stakepool Metadata Aggregation Server. People who want to stake their ada have to choose a stakepool. This means that somebody has to serve the list of all the available stakepools, and collect some data about them which can be relied on. This represents a problem in a decentralised system because while some of the data is on-chain, other bits are off-chain and are collected during the registration process.
Also, there is a need to ensure that the 'ticker' used for stakepools is not abused, since it can be built as a brand. Smash collects the data in a semi-centralised way, holding the data in a server which allows it to be queried by anybody easily, but also duplicated and checked as needed. While IOG have created the first Smash server, anyone can run one.

Software: Software, all open source...


Plutus is the base language of Cardano smart contracts. It is unique to Cardano and has been developed as the minimum set of commands required to allow the rules of a smart contract to be defined precisely. It is based on a purely functional programming language called Haskell. Using a functional rather than procedural approach allows the rules of the contract to be defined and understood in a formally verifiable way, based on mathematical proofs. This remains possible while also supporting other languages and compiling them into Plutus.


Marlowe is a language for writing smart contracts. It runs inside Plutus, but is streamlined and simplified. As a result its a GREAT place to start if you really want to learn about how smart contracts are built, and why Cardano is better than the competition. To help you out, I have created a step by step tutorial about Marlowe, so you can get a good look at it. The idea is to give you all the tools you need to build a financial contract in a form that you can learn, rather than a complete programming language which has hidden traps.


There are two pieces of software developed as clients to support the Ouroborus protocol once Shelley is released. One is written in Rust, the other in Haskell. Jormungandr is the Rust client. The two programs were developed in parallel because this allows them to be compared both with each other and with the specification at the same time. Differences are then discussed to ensure the right decision is made where it is open to opinion. Jormungandr was finished a little more quickly, so it is the one used in the first Testnet. The word Jormungandr comes from the Midgard Serpent in Norse mythology, chosen to complement Ouroborus, which is an Egyptian snake. Here is a good video explaining how to install it.

Tangata Manu

Tangata Manu is a codebase library for use by developers who want to develop wallets and explorers which link to the Cardano blockchain. It allows programmers to quickly upload the blockchain into a local database via an API, then keep it up to date. This allows projects to be developed which use a copy of the blockchain kept locally and serve it within an application. Tangata Manu is open source, download it on git.

Plutus Application Backend (PAB)

The Plutus Application Backend is the software which can be included in an application to allow it to run smart contracts written in Plutus. Smart contracts are supported by the blockchain and their rules are processed on the Cardano Computation Layer, but when an interface is being provided to the user it will need two parts to be developed to run locally as part of the application. These are the Application Backend, which is the bit that talks to the blockchain, and the Application Frontend, which is the user interface. The PAB, then, is a toolset which enables these Apps to be developed. The obvious use for it is in Wallets, to allow them to support smart contracts, but any software taking advantage os smart contract functionality is likely to need it.


Adrestia is an API. It has been developed as a bridge between higher level applications and the blockchain. If you are running a Cardano Node and you want to develop software which talks to it, like a wallet, but in fact any application which wants to see and spend ADA, you can install Adrestia and use the toolset to make your life easier. If you want to build an exchange, or build links to smart contracts, Adrestia is a great place to start. You can download it on git or You can find more information about it in the Cardano Documentation pages.

Protocols: Those carefully researched concepts and protocols...


Ouroboros is the much hailed and well researched Delegated Proof Of Stake model used by Cardano to mine transactions. The problem faced by all currencies is that everybody wants some, and many are willing to lie and cheat to get them. The currency has to find a way to verify that the funds are real and the total amount can't increase. Governments do this by having a central bank, which prints the new money and checks up on everybody. Bitcoin does it using a Proof Of Work system. Here is my simplified Bitcoin walkthough.

Ouroboros Praos

Ouroboros Praos is part of the Basho phase (Phase 4 of 5) in which the scalability problem that is inevitable in a blockchain is resolved. If a currency is going to be used predominantly across the world, and all transactions ever made are held by everyone, there are clearly going to be bottlenecks. These come in the network download speed on nodes, and in the blockchain size.
There are several weapons in the Ouroboros arsenal which will be brought into play, step by step, to allow capacity to match demand. Clearly we have a bit of time here, but we are prepared. The use of a delegated POS model is a good start, so only the stakepools need to be high resiliance, rather than every wallet. Keeping the number of pools from being too high also helps.
After that we can use sidechains which run quickly and settle on the main chain from time to time, like the lightning network. Also RINA (Recursive Internetwork Architecture) which is a form of sharding, and pruning to allow data which is not needed to validate transactions to be cleaned. Here's Charles' quick summary, and this is more technical. Finally, try the whitepaper

Epochs and slots

In Ouroboros the transactions are created during a slot by a slot leader. The slot lasts 20 seconds, so that means if your staking pool has been elected as slot leader it only has 20 seconds to create a block or it has missed its turn. The slot leader creates the block then randomly elects the next slot leader. After 21,600 slots (which is 5 days) the performance of all the staking pools is evaluated to make sure they were there when they were needed. The rewards are given out, with the fees automatically given to the pools and the rest given to the stakeholders. If some slots were missed those funds go to the treasury. This is important because we don't want successful slot leaders to benefit from failed ones since it might give them a reason to find ways to make it hard for each other. Then a new epoch begins.


ADA is the name of the coins. Most people who have got to here already know this, but its unusual for a protocol to have a different name for the coin as for the project itself. The word comes from the famous English mathematician from the 19th century called Ada Lovelace who is known for her work on Charles Babbage's proposal for the first computer. Little known fact: 0.000001 ADA is one Lovelace.


Marlowe (see above) has been developed as a way to create financial contracts, but we need to be sure it can do the job. It turns out that there is a group called the ACTUS Financial Research Foundation who make it their business to research financial contracts and define them with technical specifications. Legal jargon tries to be precise, but ACTUS go an extra step, using contractual terms and formal methods. They have created a definition of all the known standard financial contracts. Marlowe can be checked against these definitions to make sure it has the features it needs.

Settlement layer

The Cardano blockchain is built using two layers, the first one is the Settlement Layer. This is where the blocks of transactions are formed which move ADA from one address to another. It uses the Ouroborus Protocol to allow stakepools to validate and update the chain. Inside this layer are all the rules around creation of blocks and the UTXO model for moving ADA between addresses are validated. It also defines the rules for sidechains to allow value transfer on and off the main chain. Tokens created by smart contracts running on the Computation Layer would also be processed and validated here.

Computation layer

The computation layer is where the rules for smart contracts are interpreted and executed. This layer runs on top of the Settlement Layer, in that when a contract calls for transfer of value it would make a request to it.
But the computation layer supports the language of the smart contract by interpreting it. It would expect to be able to access an Oracle to gather world data, a clock to find a date and time, the blockchain to see past transactions and address balances, and data attached to those transactions.
In Cardano smart contracts can be written in lots of languages, and they are defined using a strict set of rules called the K framework.

The K framework

The K framework is the definition of the available base level commands available to smart contracts in Cardano. This framework is a scientific definition based on the idea that a mathematical proof should be possible to show that the software does what is intended. This means allowing the contract specification to be written in a formal language, and then offering a range of different languages into which it can be transposed.
Each language is fit for purpose, in that the syntax is designed to be understood clearly, but also is provably going to execute as expected. This requires a very careful mapping of the higher level language to the lower level one. The base language is called Plutus.


IELE is the Cardano blockchain virtual machine. Its pronounced Yelleh, and its the word for nymphs in Roman mythology. Don't ask me why they thought they should have nymphs running the blockchain, I assumed it would be an achronym. Maybe its an achronym as well. Anyway, its the thing that all the contract definition languages like Plutus and Marlowe run on.
There is a good description of it here and another here. Basicly smart contracts are stored immutably on the blockchain, and they have to be executed by a virtual machine that uses data such as the current time, the blockchain transactions and any data stored in them, or perhaps an oracle. The results are stored back onto the blockchain, again ummutably.
It has to interpret the language the smart contract is written in so there is a base language (like assembly code on normal computers) that it uses natively and which the contract language compiles down to. IELE is where Cardano really shines. It uses semantics based compilation to allow formal checks to be made that the contract really does what is intended, making many types of error impossible. This is possible by way of the K framework.
The fact that this is used at the bottom layer gives confidence that contracts can be relied on to do what they are meant to do without leaving openings for attack. This solid base can be built on by providing a range of different contract languages which are fit for purpose, so that tools can be built that are tailored for the user.


This is the EVM - or the Ethereum Virtual Machine - running under the K framework on Cardano. Solidity is the standard Ethereum smart contract language, and KEVM is a virtual machine that runs Solidity contracts on IELE, which is the name for the Cardano Virtual Machine. So thats easy.


Hydra is sharding for Cardano. It is called Hydra after the mythical creature from ancient Greek mythology which had lots of heads, all snakes. Whenever a snake was chopped off two more would grow in its place. Snakes are part of the Cardano image so the idea fits.
To achieve infinite scaling you need to be able to split into multiple blockchains as demand increases, with each chain building independantly, while at the same time validating all transactions on the whole. This can be done if the players on each chain can be trusted and the validity of a chain can be easily checked without rescanning. See KMZ sidechains for more on the technology.

History: Historical people and creatures things are named after...

Gerolamo Cardano (1501 to 1576)

Gerolamo Cardano - Italian mathematician, physicist, biologist, doctor, chemist, astrologer, philosopher, writer and gambler. During his life, he wrote more than 200 scientific papers and was one of the key figures in the field of mathematical probability in the Renaissance. For a cryptocurrency project that wants to use rigorous scientific methods based on mathematical proofs and game theory to build a very flexible and compatible form of programmable money, using the name of this Italian scholar makes sense, mostly.
Obviously we might want to play down the gambling connection, and dying in 1576 also cramped his style a bit. In fact, the thing he is most famous for is negative numbers, which weren't really a thing until he decided he needed them, probably due to his gambling I suppose.
Another thing we sidestepped was his rather errant son, Giovanni Battista, who was beheaded in 1560 for poisoning his wife. Apparently she was unfaithful, although we only have his word for that. Probably we should pick a different famous progeny for the coins then...

Ada Lovelace (1815 to 1852)

Ada Lovelace is an English mathematician and writer who was the first person to admit that computers can be used not only for adding up. She wrote the first algorithm used on a computer, making her the first programmer. She was years ahead of her time.

To honor her forsight and ingenuity (and because she has a short first name) Cardano has used her name for the coin, ADA. We have also used her second name, Lovelace, for the smallest sub-unit, in the same way as the smallest sub-unit of Bitcoin is called a Satoshi after Satoshi Nakamoto.
It is no coincidence that the first stage of the Cardano roadmap, which included the birth of ADA cryptocurrency in September 2017, was named after the father of Ada Lovelace - Lord Byron.

Lord Byron (1788 to 1824)

George Gordon Byron, 6th Baron Byron, was a British poet, politician, and leading figure in the Romantic movement. One of his most famous works was Don Juan, a long satirical poem in which Byron portrayed Juan as a man who was easily seduced by women, or vice versa.
Byron lived for seven years in Italy, where he became friendly with fellow poet Percy Bysshe Shelley, who was married to our next famous and important historical figure - Mary Shelley.

Mary Shelley (1797 to 1851)

Mary Shelley was an English author best known for writing Frankenstein, a novel about a scientist who creates a humanoid creature from bits of dead humans he finds lying around. Well, lying underground I think, since there was a bit of grave robbing involved. The novel was the result of a bet between Lord Byron, Percy Bysshe Shelley, and Mary Shelley about which of them could write the best horror story. I expect they never admitted her's was the best, and she published it anonomously.
If writing an infernal book about creating monsters from the dead was controvercial, it was put into shadow by her relationship with Percy. He was already married when he met her, and she went off around Europe with him at the age of 17, returning pregnant. It was ok in the end though, because his wife killed herself, so they could get married. Hmmm.
Anyway, we have used her name for the second phase of Cardano, where we join the parts together to create a decentralised system out of nothing. We're not creating a monster though - honest.

Joseph Goguen (1941 to 2006)

If it all feels like it is getting a bit incestuous, you will be relieved to hear that the third phase takes a different approach. Fast forward to Joseph Goguen, a computer scientist from the United States and a professor at universities in California and Oxford> He has held research positions at IBM and SRI International.
Goguen's work focuses on algebraic semantics and formal verification. He inspired Grigore Roche, a professor of computer science at the University of Illinois and CEO of Runtime Verification, to develop the K framework. It is used to formally check the code for smart contracts, so that they are automatically checked for defects. Many programming languages are defined in K, so there is an opportunity to allow those languages to be used for smart contracts in Cardano and formally prove that they are equivalent and safe.
Interestingly, there is a programming language called ADA (no relation) and it is very formal and precise in its structure. In the old days, when it was created, programming languages were immature, and most were informal. Goguen and the K framework were instrumental in the creation of ADA.

Matsuo Basho (1644 to 1694)

Matsuo Basho was the most famous poet of the Edo period in Japan. He created the Haiku form of poetry, which is created from three sentences of 5, 7, and 5 syllables each.
For example, Basho's 'Old Pond' is considered the most famous Japanese haiku. It can be translated as follows:
  Old pond - a frog jumping - the sound of water
Ok, so jumping frogs might not seem to have a lot to do with Cardano's fourth phase, which is about scalability, but we picked him anyway, possibly to help us to stay calm.

Voltaire Francois-Marie Aruet (1694 to 1778)

Francois-Marie Aruet, known as Voltaire, was a French writer, philosopher and historian who had influence in the Enlightenment movement. The ideas of the Enlightenment movement undermined the authority of the monarchy and the church and paved the way for political revolutions of the 18th and 19th centuries. Enlightenment also focused on scientific method and reductionism.
In fact he was a prolific writer, producing over 2,000 books and pamphlets. There are also more than 20,000 surviving letters written by him. Clearly he was keen to spread the word, and letters were the best way to get it out there in his day.
Needless to say, this made him somewhat unpopular with the authorities, but Cardano aren't planning to copy him there, we're going to be careful, and law abiding. Of course, modern laws are a bit more forgiving, hopefully.


In ancient Greek mythology, Daedalus was a skilled craftsman, innovator and artist. He is first mentioned in Homer's famous book of the Iliad and is father of Icarus.
On the Greek island of Crete, Daedalus was hired by King Minos and developed a labyrinth where the Minotaur, a creature which was half-man half-bull, was trapped. The official Cardano wallet was named after Daedalus, while the image of the Minotaur is used as its logo.
Unfortunately for Daedalus, King Minos had him imprisoned in a tower in the labrynth not long after it was completed, so that he had to escape by making wings fashioned from feathers and wax.


In the story of the Illiad, Icarus is the son of Daedalus and the two are forced to escape from the Labyrinth on a structure of feathers and wax. Daedalus is said to have warned Icarus not to fly too low or too high, as the sea will soak the feathers and the sun will melt the wax. Famously, Icarus got it wrong and flew too close to the Sun, melting the wings and falling to his death.
The prototype of Cardano's lightweight wallet, Icarus, was used as a starting point for the Yoroi wallet. Yoroi means armour in Japanese, and is a lightweight Chrome-based wallet.


Ouroboros is a symbol depicting a snake or dragon eating its own tail. Although the name Ouroboros is derived from ancient Greek, its first known appearance was in an ancient Egyptian text from around 1400 BC. The word has been adopted for the protocol in Cardano used for creating the blockchain because of the way blocks are connected to each other indefinitely.
The word ouroboros is often interpreted as a symbol for eternal cyclic renewal or a cycle of life, death and rebirth. The skin-sloughing process of snakes symbolizes the transmigration of souls, the snake biting its own tail is a fertility symbol.
All very dry. More interestingly, many academics think the tail of the snake is a phallic symbol, and the mouth is a yonic or womb-like symbol. They clearly have a very good imagination. So, this implies that the ADA blockchain is named after a sybol for oral sex. Well, I doubt that will put anyone off.

Blockchains: General blockchain concepts...


UTXO is an achronym standing for Unspent Transaction Output. The idea is quite commonly understood in blockchains because its used in Bitcoin. In this model any address containing a bit of ADA must be fully used when it is consumed in a transaction. Since the transaction has to balance to zero, and you have specified how much goes to the destination address and transaction fee, there will be some change left over. The change goes back to the spender and the source transactions get marked as spent.
The alternative is called the Account Balance model, which is used by Ethereum. Here you just take what you need and leave the rest. So UTXO is a bit like cash; you can't tear a note in half so you give the whole note away and get change back. The Account Balance model is like a bank account, deducting from the balance. There can be advantages in the Account Balance model when writing smart contracts, since it is simpler, but UTXO is considered better because the Account Balance model can be subject to double spend attacks unless measures are taken to prevent them.
With UTXO the blockchain is easier to validate since every movement of funds clears the address balance leaving no possibility of a second spend. Here is a good article explaining it in full.


UTXOma adds Multi-Asset support to UTXO. It is a new idea developed by IOHK as an alternative way of generating user-defined tokens. Ethereum and many blockchains support tokens as a side-product of a Turing complete scripting language. A token is created by a smart contract which can access a distributed database and apply rules. This is complex and means the tokens are not native to the blockchain. It leads to risk from bugs and hacks.
The UTXOma model extends UTXO to add Multi-Asset support natively using a scripting language built into the protocol and optimised for the purpose. This both simplifies the process of creating and makes the rules of the token easier to validate. Validating the tokens on the blockchain also means you don't need a centralised component, such as an asset registry or database. Here is the link to the whitepaper which describes it in full.

KMZ sidechains

KMZ stands for Kiayias, Miller and Zindros. These were the three people who wrote the witepaper defining how to generate transactions which are defined outside the Settlement Layer but carried out on it. The paper was written around the Bitcoin protocol as a "proof of proofs of work" concept, but it can be re-engineered around the Ouroborus protocol for use in Cardano.
Funds can be moved according to the rules of a smart contract, or according to any compatible rules, and might be reflected in transactions on a different blockchain. An important feature here is that a transaction can be validated without having a full copy of the remote blockchain, since that wouldn't scale.
This provides a degree of separation, so that validation of each layer can be carried out separately. It also allows for the whole project to scale, and allows smart contracts are built on a different layer. This means that rules can be invented to control tokens which live separately from ADA, similar to an ERC20 token in Ethereum. Here is the whitepaper.


Recursive Internetwork Architecture. This is the proposed mechanism by which Cardano will eventually scale beyond what is possible on a single blockchain. The Cardano protocol is fast, because it optimises the number of nodes which will mine new blocks, and does not need Proof Of Work.
Nevertheless it cannot scale enough to suport all the transactions of the world on a single chain. For that it needs to run multiple parallel chains and have the ability to recursively spawn new capacity when it is needed, growing according to throughput. This will be the job of RINA, and it will be implemented only when it is fully developed, tested, and needed.

Assurance level

Assurance levels are not special to Cardano; all blockchains have them. When your transaction is added to the block on the end of the chain it means a miner has validated it. However, from the point of view of the receiver, things can still go wrong. Maybe the miner is dishonest, or maybe a different chain might be adopted by the world because it is longer.
The transaction becomes gradually safer as blocks are built on top of the block it is in, since re-organisations rarely happen which affect more than a couple of blocks. When the block containing your transaction has less than 3 following blocks it has "low assurance", up to 8 blocks is medium, and 9 or more is high. The last 9 blocks would never get completely rewritten in a good decentralised blockchain.
If blockchains confuse you, my page explaining how they work might help.

Psi calculus

Psi calculus is a branch of mathematics which allows the sense-compute-act cycle used in programming languages to be generalised and defined in a mathematically rigorous way. The process involves defining a space, objects in the space, and definitions of the interactions between them in an algebraic style, so that the properties of the whole can be formally understood. It can be used to develop specifications in a form that can be transposed into software while guaranteeing that the original purpose is not lost in translation. Psi calculus is the basis of Plutus.

Merkle tree

Everything in a blockchain seems complicated at first glance, but in fact its quite simple. When a miner is building a block out of transactions there might be quite a lot of data in the block, maybe a megabyte. The trouble is that working out a SHA256 hash of a million byte string is slow work, so he wants to break it up into bite sized chunks.
The miner finds the hash of each transaction one at a time. The hashes are short, so now he can then take pairs of hashes and hash each of them. Then take pairs of those hashes to produce another set with half as many values. Then keep going combining pairs, until he only has one hash. The last one is the root.
If any of the data in the block changes it will be easy to spot, since it will invalidate the calculations of dependant hashes, and which always include the root.
In software terms this is a tree, because it has a root with branches below it, then branches on those branches, etc. Trees are quite common in software.
Merkle trees got their name from Ralph Merkle because he invented them and got a patent in 1979. In my explanation each hash is created from two hashes from the level below, making it a binary merkle tree. This is the most common type, since it can be shown to be the fastest, but you can create a tree with more branches coming from each node if you like, and if your blockchain rules allow it.

This website was created by Kevmate. Its all my own work. Contact me by emailing me at kev@kevmate.com