Future-proofing Blockchain Technology: QRL Uses Quantum Physics

Crytocurrency is uncharted waters for the whole of humanity. Even software developers and technology enthusiasts, the vanguard rushing into the field, know little about it and its possibilities. Consequently, there are some projects — those that aren’t flimsy and have little reason to exist — trying to see what the state of the blockchain industry will be a few years down the line.

What are the possible technological hurdles? What can serve as encouragement for adoption? Will current security measures, fundamentally important to blockchains, ever go obsolete?

While many projects are addressing the first two questions, via scaling solutions and enterprise adoption, the last one remains the focus of a very select few. Many coins are so determined to gain immediate recognition that they overlook the necessity of some long-term strategy, the absence of which could bring forth their demise.

Of the many ways that blockchain could be made to make self-preserving detours in the future, quantum computing stands as one as that is steadily approaching and almost inevitable. Blockchain technology thrives from the security of its protocol and this security is offered by asymmetric encryption.

Quantum computing could reshape the entire landscape of cryptography — and that could be a disaster for blockchain.

Quantum computing

In a previous article, we went into detail about what quantum computing is and how it could affect the progressive momentum of blockchain technology. Here, we’ll just quickly run through what quantum computing is before talking about how one particular project is looking to nip that problem in the bud.

Quantum computers, unlike classical computers, operate on qubits. Today’s computers operate on bits, which can exist in a state of either 0 or 1. Qubits can exist in both states simultaneously. As the number of qubits increase, the power of the quantum computer increases exponentially, at a rate that a classical computer cannot keep up with it.

This gives a quantum computer enormous power, letting it solve problems that are simply unresolvable with a classical computer.

However, one of these “problems” or rather, challenges, is that of cryptography. Today’s asymmetric cryptography standards, such as those used in on a blockchain, can theoretically be broken by a classical computer. It would just take a lot of time. Quantum computers, with their increased efficiency, could solve it much quicker with their better computing capabilities. This would render all encryption today useless and question the use of blockchains.

There are several other concerns regarding the advent of quantum computing. A “51% attack” on a blockchain network is when miners attempt to take over 50% of the network, allowing them to double spend and delete transactions from the ledger. A quantum computer could give them the processing power they need to do this. While this is a secondary concern about quantum computing, it exists nonetheless. The slated arrival of this capability is roughly 10 years.

The timeline for the arrival of quantum computing is disputed, but the general consensus is that it will make its appearance in ten to fifteen years. That timeline may even be shortened; recently, researchers at the University of South Wales designed a new quantum architecture similar to today’s computers. This system was capable of producing quantum calculations and is capable of being run on devices similar to the ones we use today. This is a major step forward for the quantum computing industry.

While it may be more than a decade before the first quantum computers arrive, blockchain developers must still prepare early for that future. Enormous funding is being poured into quantum computing research; its arrival is almost inevitable. That same urgency is not present with this particular aspect of blockchain — that of quantum immunization — and it could pose a serious problem to the industry’s growth.

It is therefore necessary to address this issue sooner or later. To tackle this issue before it can become a problem, some projects, like the Quantum Resistant Ledger, is laying out plans to prevent quantum computing’s eradication of blockchain security before it can begin.

The Quantum Resistant Ledger

The Quantum Resistant Ledger (QRL) is a coin whose foremost selling point is its intention to future-proof decentralized currency and tackle the threat of quantum computing. It is an ERC20 token, based off on the Ethereum blockchain, that runs on a Proof-of-Stake algorithm. Few coins are tackling the threat of quantum computing (IOTA is another one) and none in the manner that QRL is taking.

The project is led by Dr. Peter Waterland. It began as an idea in August of 2016. Soon after, a Proof-of-Work algorithm was designed based on Merkle signatures and Lamport Schemes. The QRL team then spent some time discussing the technology with developers and cryptographers, following which they released their white paper.

What Exactly is QRL Trying to Do?

The project itself describes itself as “meeting the needs of today while addressing the demands of tomorrow”. The project’s goal is to provide users with the same features as cryptocurrencies like Bitcoin and Ethereum, while also providing fairer mining processes, stronger security and better staking algorithms.

Their toke, Quanta, is what will power the transactions across the network while also acting as a repository of value. Currently, the token is valued at $2.42 (as of January 21, 2018) with a market cap of about $125 million. The circulating supply is 52 million while the maximum supply is 65 million.

QRL has hit an all-time high value of $3.70 and a market cap of $192 million. The coin has been performing well in recent months. The integration of smart contracts and introduction of an “ephemeral layer” in 2018 should bode well for the coin’s value.

The Technology that Provides Quantum-proof Security

QRL’s only really distinguishing feature is that it provably provides security against quantum attacks, or so the team says. A number of technological schemes go into achieving this which we’ve explained in brief below.

Additionally, QRL introduces a novel Proof-of-Stake mechanism that shifts requirements away from hardware mining equipment.

Let’s first take a look at what gives QRL its quantum-proof security.

Extended Merkle Signature Scheme (XMSS)

The Extended Merkle Signature Scheme (XMSS) is what provides security against quantum attacks. The signature scheme has been vetted and peer-reviewed. This scheme uses a one-time signature that can be associated with only one key. These keys are also generated on demand which means they are effective against pre-meditated attacks.

There are a series of solutions that could possibly work against quantum attacks, but the one XMSS is classified under, hash based signature schemes are generally agreed to be the best choice. It is resistant to quantum computers running Shor’s algorithm.

A random seed key is generated to offer an additional layer of security. It is from this seed that a set of pseudorandom keys will be generated. An XMSS address is derived frm the public key which contains the seed and merkle root. Wallets and nodes can generate numerous variations of the XMSS tree, which allows for as many unique addresses to be created.

Novel PoS

If you’ve been diving into the world of blockchain, then you will have come across the terms Proof-of-Work and Proof-of-Stake. These are two different approaches to how the blockchain network arrives at a consensus on the state of the blockchain.

Bitcoin operates on the Proof-of-Work algorithm. While it is effective at what it does, over time, as the blockchain size increases, it requires an increasingly more intensive computation to calculate the next block on the blockchain. The hardware power required to do this grows exponentially. The problem with this is, while also demanding high resources, it also pushes the mining process towards centralized entities who have the necessary resources.

Proof-of-Stake seeks to work around that problem by rewarding users on the network through the staking of coins. In QRL’s custom algorithm, any user with QRL in their accounts can choose to stake. These nodes, called stake validators, will compete with each other to produce a “winning adjusted hash value” blockheader. The strongest block travels around the network and is used in the next POS cycle. Hash values for each validator are predetermined and precautions have been put in place to prevent cheating.

All you really need to know is that this system is lightweight and flexible, and the stake with the highest number of QRL is most likely to win. This is not hardware intensive and anyone with an ordinary computer has a chance to win rewards.

QRL in Simple Terms

Here’s a much simpler explanation of QRL’s systems, sans technical jargon.

Current cryptocurrencies like Bitcoin are not quantum proof. Shor’s algorithm, running on a sufficiently powerful computer like a quantum computer, can break through the cryptographic schemes that protect most blockchains.

QRL is attempting to establish quantum-proof blockchains because quantum computing could evolve rapidly, putting the blockchain industry at risk. To do this, it uses a special signature scheme called hash based signatures. These are proven to be effective and lightweight. From a seed value that is generated from a public key, a number of one-time addresses can be created that are impossible to be forged or be the target of pre-determined attacks. This seed value is pseudo-random.

In other words, it is difficult for a quantum computer to break this encryption method because the tree of values that is created by XMSS is sufficiently complex and random that even a quantum computer could not break it.

This is a very broad and high level explanation of how the mechanism works, but it is the gist of QRL’s work. Their whitepaper is well worth a read if you would like to know the nitty gritty of how they secure the blockchain. It is highly technical in nature.

The QRL Team

The Quantum Resistant Ledger Team has strong credentials. The team is led by Dr. Peter Waterland, a core developer. The team is composed of PhD students and software experts, with specialities in post-quantum cryptography and blockchain technology. There are about 13 members in the team currently.

Is it a Solution or a Band Aid?

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It’s a gamble to make any predictions in technology. A lot can happen over one year. While QRL states that their quantum-proof mechanisms are a impenetrable way of defending against quantum attacks, it should not be counted against technology that it will not be able to derive a work around to this problem. The XMSS scheme is supposed to make it complex enough that brute force analysis will not be possible. However, perhaps quantum computing in combination with Artificial Intelligence will draw up a solution.

QRL must also successfully execute this project and be stress tested to check its integrity. Their solutions to the quantum problem must not be a band aid, but a permanent, tried and tested defense against the inevitable future.

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Conclusion

The Quantum Resistant Ledger is indeed stuff of substance and not merely style. The detailed descriptions of their technical architecture indicates that they truly believe that it can secure blockchain in an age of post-quantum cryptography. The XMSS mechanism must now be tested in a public setting — it is the execution of this coin that will determine its survival. While introducing this protection against quantum attacks so early is good to hear, one wonders where it can still manage to topple Bitcoin and Ethereum, regardless of the difficulty those blockchains might have in bringing quantum protection. That remainds to be seen.