Citadel SDK & Rusk VM 2.0: Mainnet Deliverables are Shipped

Citadel SDK and Rusk VM 2.0 are shipped

Today is an incredibly exciting day, as we can announce our first 2 milestones on the road to mainnet, the Citadel SDK and Rusk VM 2.0, are both delivered! The delivery of the Citadel SDK and Rusk VM 2.0 mark the first two deliverables for the timely and successful delivery of mainnet. 

Both are huge achievements for the team, and the community can be proud of the work that is being done. 

Not to mention the fact that both are ground-breaking firsts for the blockchain industry!

The Rusk VM 2.0 will make Dusk the only ZK-friendly Layer One capable of supporting confidential smart contracts, while Citadel is the first decentralized and private identity tool capable of performing KYC in a way that is both compliant and private. 

Let’s have a look at what is being shipped, and then go into a deep dive on what each deliverable is, why it was needed, and how it fits into the wider Dusk ecosystem and mission. 

Rusk VM 2.0 - a privacy-friendly virtual machine for powerful use cases

Rusk VM 2.0 is the first virtual machine that can natively support privacy preserving smart contracts, while also allowing for ultra lite clients with the instant, trustless sync up of nodes and wallets. 

It solves many problems faced by other blockchains, and is the foundational piece of our broader mission. 



See the code for yourself!



VM and smart contracts tutorial

Key points

  • The Rusk VM 2.0 is ZK-friendly and can support natively deployed confidential smart contracts, both for institutional users and individual developers. 
  • It manages storage infinitely better than competitors, and clients can sync up almost instantly downloading one block, rather than taking days/weeks/months/years to download the entire blockchain. 
  • It is up to 500% faster than its predecessor (Rusk VM 1.0) and scales infinitely. 


The Citadel SDK - KYC Redesigned 

Next up, we have the Citadel SDK, our decentralized, privacy-friendly licensing tool, which is especially designed for know-your-customer (KYC) and anti-money-laundering (AML) needs. If we want on-chain, decentralized finance, we need an on-chain, decentralized identity tool. That tool is Citadel. 

Citadel is both more efficient than current identity solutions, is specially built to be privacy-friendly and to fit into decentralized systems, and paves the way for business adoption of DLT. 



Check out the code for yourself!



Citadel Wiki with tutorial

Key points

  • Citadel makes Dusk the first Layer One to have an out-of-the-box identity protocol.
  • Even better, it’s ZK-based and privacy-preserving.
  • It allows anyone - be it an institution, a DEX, or a subscription service - to provide (or deny) access to services without revealing the details of the user. 
  • It facilitates the onboarding of regulated finance by allowing institutions to perform their checks, while keeping a users’ data private, and being compatible with blockchain. 
  • It is a huge improvement on the current system, being more efficient and saves time and resources. 

Get to know Rusk VM 2.0 and Citadel

Want to know more about both of these innovative products? Keep reading, and get a deeper understanding of what both of these products are, how they work, and why they solve a myriad of problems. 

A Deeper Dive: The Rusk VM 2.0 

The Rusk VM 2.0 is our novel, and groundbreaking, virtual machine that will power not only the Dusk infrastructure, but all of our partners who build on top of us, and secure billions if not trillions of dollars worth of assets. This is the second iteration of our virtual machine and brings with it a lot of improvements and benefits over its predecessor.

It is the foundational piece of a financial system that is decentralized, private, and permissionless.

This is where it gets a bit technical! There are 3 layers that make up the virtual machine: Web Assembly, Piecrust, and the Rusk nodes, with “Rusk VM 2.0” being the term that refers to all 3 of these layers. 

Web Assembly is the base layer, and executes transactions. However, it knows nothing about blockchain, so Piecrust is the next layer and “teaches” Web Assembly about blockchain. Piecrust, however, knows nothing about zero-knowledge, so Rusk VM 2.0 makes it possible to transact in a way that is privacy-friendly. 

Why was the Rusk VM 2.0 necessary?

One of the hardest things about crypto is cutting through the noise, so while it may appear that there are many privacy-friendly projects out there, most (if not all) are built on top of existing systems, either as applications or as Layer Twos. 

This wasn’t good enough for us; we needed infrastructure that met our needs, and thus we needed a Layer One that was privacy-friendly from the beginning, and that used zero-knowledge proofs not to scale existing blockchains, but to provide privacy. This is not possible when building on top of a system that wasn’t designed for privacy, the information leaks somewhere. 

Secondly, we found other VMs out there to have long-term difficulties when it came to storage and scalability and we foresee that many will have issues further down the line. As such it was necessary for us to build our own virtual machine from scratch in order to ensure that Dusk is always easy to use and doesn’t suffer from memory or scalability issues. 

What is Rusk VM 2.0?

Rusk makes Dusk the only Layer One blockchain capable of deploying natively privacy-preserving smart contracts.

Privacy and compliance are built in from the ground up, enabling real real-world assets to not only be tokenized on-chain, but to be natively issued on-chain, thus ushering in a new, decentralized form of finance that is faster, more efficient, and more effective.

This is the first step in our journey towards becoming the first decentralized financial market infrastructure (FMI) for regulated assets, that is capable of replacing vast amounts of outdated processes and middlemen, and make financial assets, capital, and most importantly, opportunities for financial freedom and inclusion, available to all. 

The problems Rusk solves

Rusk is faster, more scalable, and more private than anything that exists out there. 


It is privacy-friendly and allows for the deployment of confidential smart contracts. This means that anyone can deploy smart contracts that preserve users’ privacy, be it a stock market exchange or an anonymous developer building a DEX. 

This opens up so many possibilities, as privacy is now the standard and the default, not the exception or the modification.

Infinitely better memory storage 

The Rusk VM 2.0 is also leaps and bounds ahead when it comes to memory and state management.

The challenge most blockchains face is that when a new client wants to join the network, as a node provider for example, they have to sync up to the network. This has meant downloading every single block the blockchain has produced, all the way back to the genesis block. 

This takes a long time! Weeks, months, and in the future, years. 

With the Rusk VM 2.0, new joiners to the network only have to download the latest block, and are instantly caught up with the entire blockchain. 

This makes it so much easier to participate in the network and is a revolutionary way to manage “state bloat” that would otherwise make it all but impossible for new clients to join the network. 

Up to 500% faster than before

The new VM is also fast, much faster, than its previous iteration performing up to 5x more transactions per block than its predecessor. While testing it was also found that improvements do not scale linearly, but infinitely. 

Complex proofs have to be generated in order to generate ZKPs and confirm the transactions, and to have sped the processing so much is a huge achievement. We now have the foundations for a Layer One blockchain that is fast and private.

A Deeper Dive: Get to Know Citadel

Why was Citadel necessary?

Citadel was needed both to bridge regulated finance on-chain, and to improve the KYC process more broadly. With Citadel it is possible to verify someone’s credentials without needing to know who they are. 

It’s an amazing application of zero-knowledge proof cryptography, where your proof acts as a pass that either opens the door to a service, or it doesn’t, but no personal information is shared. 

This is a huge win for privacy, decentralization, and the onboarding of the trillion dollar market of real-world assets. We also see regulations like this start to creep into DeFi with DEXs starting to require KYC. 

What is Citadel?

Citadel is a privacy-preserving, decentralized licensing tool that has a number of exciting applications. It essentially issues a pass or access card (known as a “proof”) that can be used to prove that you have the right to use services or products, without having to reveal your identity or personal information. 

The experience of using it is much like using a building pass; if you have the authorization to enter a room, the door will open when you present your key. If you don’t, then it doesn’t. 

Citadel can be used for KYC, subscription services, and a whole host of other things. If you need to have a way of verifying who can access your platform, due to paying a membership fee or being of the right age or not from a banned jurisdiction, Citadel does this for you in a way that is private, decentralized, and on-chain.

The problems Citadel solves

More efficient 

The current approach to KYC is clunky and inefficient, with enterprises spending billions to replicate a process that has already been done. This inefficiency costs money, prevents competition by making it hard for new and innovative firms to enter the market, and puts users at risk due to sharing their information so widely. 

With Citadel, you provide your details once, for example to your bank, and are then issued with a license which you can use to access other services and products. It’s like getting a pass card, and rather than having to share your details, you just swipe your card. 


Instead of having to share who you are, you share your proof which proves no more and no less than that you are able to access these services. 

There is no reason to continually leak information when all a provider needs to know is that you can access their services. Citadel preserves your privacy while allowing you to interact with regulated assets, while also making it easy for enterprises, institutions, or lone wolf developers to create services that are compliant. 

This is groundbreaking, for institutions who no longer have to spend billions verifying information that has already been verified, and for users who don’t want to have to give their data to everyone when all they need to prove is that they are over a certain age, or from a certain jurisdiction. 


In order to deal in regulated, real-world assets, organizations must comply with regulations. Citadel meets the requirements of the EUDI directive for digital wallets, and thus makes it easy for everyone to be compliant while enjoying the benefits of blockchain. 

Without this tool, protocols and institutions will either not be compliant, or they will have to rely on outdated KYC methods which are highly centralized, expensive, do not integrate well with blockchain, and do preserve users’ privacy. 

Beyond KYC

Citadel is not only for KYC, although that is a strong use case. Citadel can also be used for subscription services, memberships, tickets, even digital identities. 

The Road Ahead

Both Citadel and the Rusk VM 2.0 set a new standard in blockchain technology. Prioritizing privacy and efficiency, these are both 2 vital tools to enabling decentralized finance at its highest level, with the potential of decentralizing and increasing access to traditional financial tools, slashing costs, and opening up the economy. 

The unique blend of privacy, decentralization, and solutions to the toughest problems facing institutions and blockchains alike, makes Citadel and the Rusk VM 2.0 not only two achieved milestones for us, but two groundbreaking additions to the blockchain and finance space.