Quantum computing has raised concerns about the future of cryptocurrency and blockchain technology in recent years. For example, highly sophisticated quantum computers are thought to one day be able to break current cryptography, making security a concern for users in the blockchain space.
The SHA-256 cryptographic protocol used for the security of the Bitcoin network cannot be broken by today’s computers. However, experts predict that within a decade, quantum computing could break existing encryption protocols.
As for whether holders should worry about quantum computers being a threat to cryptocurrency, Johannes Poleczak, chief technology officer of QAN Platform, a layer-1 blockchain platform, told Cointelegraph.
“Of course. Elliptic curve signatures – which are powering all major blockchains today and have proven to be vulnerable to QC attacks – will be deprecated, making it the only verification method in the system. Once compromised, it becomes virtually impossible to distinguish between a legitimate wallet owner and the hacker who created one’s signature.
If current cryptographic hash algorithms are cracked, hundreds of billions worth of digital assets are vulnerable to theft from malicious actors. However, despite these concerns, quantum computing still has a long way to go before it becomes a viable threat to blockchain technology.
What is quantum computing?
Modern computers process data and perform calculations using “bits”. Unfortunately, these bits cannot exist in two places and in two different states at the same time.
Instead, traditional computer bits can have a value of 0 or 1. A good analogy is when a light switch is turned on or off. So, if there is a pair of bits, for example, those bits can only hold one of four possible combinations at any given time: 0-0, 0-1, 1-0, or 1-1.
From a practical point of view, the implication of this is that complex calculations that need to consider each and every possible configuration can take a lot of time on an average computer.
Quantum computers do not operate within the same limits as traditional computers. Instead, they use something called quantum bits or “qubits” instead of traditional bits. These qubits can exist simultaneously in the 0 and 1 states.
As we mentioned earlier, two bits can contain only one of four combinations. However, a pair of qubits can store all four at the same time. And the number of possible options grows exponentially with each additional qubit.
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As a result, quantum computers are performing multiple calculations simultaneously considering different structures. For example, consider the 54-bit Sycamore processor that Google built. The world’s most powerful supercomputer was able to complete a calculation in 200 seconds that would take 10,000 years to complete.
Simply put, quantum computers are much faster than traditional computers because they use qubits to perform multiple calculations simultaneously. In addition, since qubits can have a value of 0, 1, or both, they are more efficient than the binary bit system used by current computers.
Various attacks of quantum computers
Hoarding attacks involve a malicious party attempting to steal funds by targeting vulnerable block addresses, such as addresses where a wallet’s public key is exposed on a public ledger.
Four million bitcoins (BTC), or 25% of all BTC, are vulnerable to an attack by a quantum computer due to owners using unhacked public keys or reusing BTC addresses. The quantum computer must be powerful enough to distinguish the private key from the undeciphered public address. If the private key is successfully decrypted, the malicious actor can steal the user’s funds directly from their wallet.
But experts estimate that the computing power required to carry out these attacks would be a million times greater than existing quantum computers, less than 100 qubits. However, researchers in the field of quantum computing have hypothesized that the number of quantum numbers in use in the next ten years could reach 10 million.
To protect themselves from these attacks, crypto users should avoid reusing addresses or moving their funds to addresses where the public key has not been published. This sounds good in theory, but it can be very tedious for everyday users.
Someone with a powerful quantum computer could launch a transit attack and try to steal money from the blockchain transaction in transit. Since it applies to all transactions, the scope of this attack is very wide. However, executing it is more challenging because the attacker must complete the transaction before the miners can execute it.
In most cases, due to the verification time on networks like Bitcoin and Ethereum, an attacker has no more than a few minutes. Hackers also need billions of qubits to carry out such an attack, making the risk of a transit attack much lower than a storage attack. However, it is still something that users should consider.
Protecting yourself from attacks while traveling is no easy task. To do this, it is necessary to change the cryptographic signature algorithm underlying the blockchain to one that is resistant to quantum attacks.
Measures to protect against quantum computing
A significant amount of work needs to be done on quantum computing before blockchain technology can be a credible threat.
Furthermore, blockchain technology is very likely to solve the issue of quantum security when quantum computers are widely available. There are cryptocurrencies like IOTA that use directed acyclic graph (DAG) technology as quantum-resistant. Unlike the blocks that make up a blockchain, directed acyclic graphs are made up of nodes and connections between them. Therefore, records of crypto transactions take the form of nodes. Then the records of these exchanges are stacked on top of each other.
Block Lattice is another DAG based quantum resistive technology. Blockchain networks like the QAN Platform use the technology to enable developers to build quantum-resistant smart contracts, decentralized applications, and digital assets. Lattice cryptography is resistant to quantum computers because it is based on a problem that a quantum computer cannot easily solve. The name given to this problem is Short Vector Problem (SVP). Mathematically, SVP is a question of finding the shortest vector in a large-scale lattice.
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Due to the nature of quantum computing, SVP is considered difficult for quantum computers to solve. A quantum computer can use the principle of superposition only when the quantum states are perfectly aligned. A quantum computer A quantum computer can use the principle of superposition when quantum states are perfectly aligned. Again, more conventional calculation methods must be used when regions are not present. As a result, a quantum computer is more likely to succeed in solving the SVP. This is why lattice-based encryption is secure with quantum computers.
Even traditional organizations have taken steps towards quantum security. JPMorgan and Toshiba have teamed up to develop quantum key distribution (QKD), which they claim is quantum secure. Using quantum physics and cryptography, QKD can identify any effort by a third party to track the transaction while simultaneously trading confidential information. The concept is being seen as a useful security mechanism against hypothetical blockchain attacks that future quantum computers may carry out.