Chain Key Cryptography: The Research Behind the Dfinity Internet Computer

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Blockchain is an innovation that has so much promise. In fact, by 2024, it’s estimated that businesses will spend over $20 billion every year on blockchain technology.

 

Although we can use the blockchain in nearly any industry and for many purposes, the technology currently has limitations. Many blockchain solutions are slow and difficult to scale.

 

Fortunately, blockchain brands like Dfinity are putting in the research to change the future of blockchain, enhancing the possibilities of this technology.

 

Dfinity’s Internet Computer (IC) uses protocols that revolutionize our understanding of the blockchain. This autonomous, independent blockchain is constantly innovating, and it’s all thanks to the engine powering the IC: Chain Key cryptography.

 

Let’s see how Dfinity’s Chain Key cryptography solves some of blockchain’s most significant pain points.

 

How Dfinity Began

Founded in 2016, Dfinity is a nonprofit based in Switzerland. Created by Ethereum’s former technologist, Dominic Williams, Dfinity now has a global footprint. From Japan to the United States, Dfinity’s growing 200-person team is revolutionizing the future of blockchain.

 

Dfinity has grown to become a favorite of blockchain enthusiasts, developers, and everyday users in the years since its inception. Thanks to its flagship Internet Computer offering, Dfinity is building the next stage of the internet without any centralized infrastructure.

 

While the Internet Computer is a remarkable invention on its own, it requires a lot of moving parts to operate efficiently. That’s why Dfinity rolled out Chain Key cryptography for the Internet Computer, building an infrastructure that never needs downtime for maintenance or upgrades.

 

The Research Behind the Internet Computer

To understand how revolutionary Chain Key technology is, we have to understand the research that went into Dfinity’s Internet Computer.

 

The IC is a very different breed of blockchain because it’s completely decentralized. It doesn’t use any infrastructure from Amazon, Microsoft, or Google, and it houses itself in independent data centers across the world.

 

The IC is made up of several subnets, which are composed of different nodes at different data centers. The IC protocol connects these nodes to canisters (small snippets of code) that execute specific tasks.

 

What’s impressive about the IC is that each canister runs on multiple nodes. Since the IC is designed to avoid single points of failure, the system never relies on a single node for an entire functionality. This also means the different nodes have to come to a consensus to execute orders, which is where Chain Key cryptography comes into play.

 

Dfinity designed the IC to evolve, so change is built into its DNA. Nodes can be added and removed from each subnet for security reasons, data center capacity, or hardware failures.

 

But since the nodes have to reach a consensus to execute a task, how do you reach a consensus when the nodes change all the time?

 

The answer is Chain Key cryptography.

 

What Is Chain Key Cryptography?

Chain Key is an innovation that makes it possible for the Internet Computer to scale autonomously. Chain Key is a cryptographic protocol that controls all the nodes in the Internet Computer’s various subnets.

 

Chain Key is an incredible innovation thanks to its smaller size. This Chain Key is just 48 bytes, which is very small compared to ethereum’s 400-gigabyte public key. It also isn’t necessary to add more blocks to the Internet Computer thanks to Chain Key, which keeps the blockchain moving at lightning speed.

 

Remember, the IC is made up of different subnets that are composed of different nodes across the world. They have to reach a consensus, but this needs to happen securely and quickly. Each subnet has its own public key, which it uses to authenticate messages. The nodes in that subnet have to sign off on this message, which they do with their secret keys.

 

While this process alone is pretty fascinating, Chain Key cryptography is changing the future of blockchain thanks to its three major features.

1. Single Public Key

Thanks to Chain Key, the Internet Computer has a single public key —  a huge advantage. This means any device can verify transactions on the Internet Computer, which isn’t possible with bulkier blockchains like Ethereum.

 

Chain Key also makes key management much easier. It means the blockchain can use the same subnet with a public key that doesn’t change, even as the nodes that comprise that subnet change.

2. Node Scalability

Chain Key cryptography allows the IC to add new nodes and subnets without limits, which means the blockchain can grow indefinitely.

 

This might sound like a security nightmare, but not with Chain Key cryptography. The IC doesn’t allow all its nodes to indefinitely store information. That would make the blockchain too bloated and slow down the user experience.

 

When new nodes join a subnet, they don’t see the full blockchain because that information is already removed. A catch-up package (CUP) lets the nodes jump to a specific part of the blockchain to start verifying messages. In practice, this means it isn’t a big deal if a subnet needs to add new nodes.

3. Internet Computer Upgrades

Upgrades are essential to keeping the IC running, but Dfinity wanted to create a blockchain that didn’t require downtime. With Chain Key cryptography, the algorithm behind the IC (Network Nervous System) can work autonomously.

 

This means the algorithm is capable of determining which nodes go to which subnet, assigning public keys, and upgrading nodes without downtime. With this setup, the IC can fix bugs and add new features while the system stays online.

Dfinity’s Research Improving Chain Key Cryptography

 

The great thing about blockchain technology is that it’s constantly evolving. Thanks to Dfinity’s research team, the IC can evolve automatically. To do this, the research team added several helpful processes to the IC blockchain.

Catch-up Packages

Dfinity’s CUPs are essential for securely adding or replacing nodes on a subnet.

 

CUPs allow the IC to revive a subnet if all its nodes crash. The IC will even generate new keys for the subnet. Although each subnet has a single public key, the parties using that public key can’t track changes to each node’s secret key.

 

So how do the nodes know where to jump into the blockchain? CUPs instruct the nodes to run a different version of the protocol, so they don’t require previous states to keep moving forward.

NIDKG Protocol

One of the big benefits of using the Internet Computer is that it’s so autonomous. Another cryptographic technology, called noninteractive distributed key generation (NIDKG), allows each subnet to stay the same, even if it changes the nodes that comprise the subnet.

 

Thanks to the NIDKG protocol, the IC has the power to create new subnets as needed. The IC shares encrypted keys to nodes on a particular subnet, but nodes can’t access encrypted keys that aren’t shared with them.

 

If a node is compromised in a cyberattack, it can hurt the system as a whole. That’s why Dfinity’s NIDKG protocol will refresh shares of a signing key and delete old key shares, so even if an attacker has access to old keys, they’re useless and the system remains secure.

Enhanced Security

Although the Internet Computer is incredibly secure, Dfinity’s research team built it on the principle of zero trust. The IC inherently distrusts nodes, which means the blockchain needs to verify that all of its messages truly come from the Internet Computer. That’s why the entire system requires every node in a subnet to sign off on a message; if one node is out of sync with others, the system doesn’t sign off on it.

 

Chain Key cryptography gives each node a secret key, which allows it to sign a message. Every node has a different component of that key and doesn’t know the keys of other nodes. If a node is attacked, the IC will replace the secret key share.

 

The system isn’t infallible, but the Chain Key setup makes it much more difficult to compromise the integrity of the Internet Computer.

 

Chain Key Cryptography: A Secure, Faster Future for Blockchain

Dfinity’s Internet Computer was already a breakthrough. Thanks to the efforts of its research team, Chain Key cryptography has the power to make this decentralized blockchain faster and more powerful than any other infrastructure.

 

Thanks to this innovation, there are no limits to the IC’s storage capacity. That means we’ll see cleaner integrations, better smart contracts, and improved security in the blockchain, thanks to Chain Key cryptography.