In recent years, there has been a substantial amount of research on quantum computers – machines that exploit quantum mechanical phenomena to solve mathematical problems that are difficult or intractable for conventional computers. They can process huge datasets in a fraction of a second that would have previously taken days and weeks. This speeds up Big Data analysis, searching very large, unstructured, unsorted data sets discovering patterns or anomalies extremely quickly. While quantum computing promises unprecedented speed and power in computing, it also poses new risks.
Cyber security has also become very important as Cyber-attacks are growing in number as well as sophistication. And Cyberwarfare is being used to damage enemy’s critical information infrastructure including electricity grids, health sector, water supplies, telecommunications, and banking
Quantum computers shall bring power of massive parallel processing, equivalent of supercomputer to a single chip. They can consider different possible solutions to a problem simultaneously, quickly converge on the correct solution without check each possibility individually. This dramatically speed up certain calculations, such as number factoring.
Quantum Computer will also be a threat to our cyber security. Security of our critical infrastructure depends on cryptography that provides security services such as confidentiality, integrity, authentication, and non-repudiation.
As this technology advances over the next decade, it is expected to break some encryption methods that are widely used to protect customer data, complete business transactions, and secure communications. Thus a sufficiently powerful quantum computer will put many forms of modern communication—from key exchange to encryption to digital authentication—in peril.
While traditional computers use bits to store and process information, quantum computers use qubits, which can exist in multiple states simultaneously. This property of quantum computing allows them to perform certain calculations much faster than classical computers, making them a powerful tool for solving complex problems that would take traditional computers a long time to solve.
However, this same property of qubits also makes quantum computers a potential threat to digital infrastructure. One of the key areas of concern is the potential impact of quantum computers on encryption.
Cryptography is based on mathematical problems that are extremely difficult for conventional computers to solve or avoid. However, the quantum machines of the future will be able to do so more easily, making our protection systems obsolete.
Many encryption algorithms used today are based on the difficulty of factoring large numbers, a problem that is currently very hard for classical computers to solve. However, quantum computers have the potential to make this problem much easier, which could compromise the security of many encrypted communications and transactions.
Vulnerability of Asymmetric cryptography or public-key cryptography
Many of our most crucial communication protocols rely principally on three core cryptographic functionalities: public-key encryption, digital signatures, and key exchange. Currently, these functionalities are primarily implemented using Diffie-Hellman key exchange, the RSA (RivestShamir-Adleman) cryptosystem, and elliptic curve cryptosystems. The security of these depends on the difficulty of certain numbers theoretic problems such as Integer Factorization or the Discrete Log Problem over various groups.
The security of these cryptographic algorithms is vulnerable to progress of computing technology, development of new mathematical algorithms, and progress in quantum computing technology. A quantum computer of sufficient size will be capable of executing Shor’s Algorithm, factorization of large prime numbers in hours or days compared to classical computer that would take billions of years of computing time to complete.
There are two approaches for encrypting data, private-key encryption and public-key encryption. In private-key encryption, users share a key. This approach is more secure and less vulnerable to quantum technology, but it is also less practical to use in many cases.
The public-key encryption system is based on two keys, one that is kept secret, and another that is available to all. While the public key is widely distributed, private keys are computed using mathematical algorithms. Therefore everyone can send encrypted emails to a recipient, who is the only one able to read them. Because data is encrypted with the public key but decrypted with the private key, it is a form of “asymmetric cryptography”.
Factorization involves decomposing a number into a product of two prime numbers, which is much more tricky than it seems when dealing with very large numbers. Similarly, for the time being, no algorithm can effectively calculate a discrete logarithm.
Breaking this encryption without the private key would mean finding the “prime factors” used to create the public key. These are two prime numbers that are multiplied together as part of the encryption process to form part of the public key. For sufficiently large prime numbers this is considered an impossible task for today’s computers.
“The algorithms are designed in a way that acquiring the private keys from the public keys is nearly impossible,” he said. “For traditional computers, for example, it would take thousands—to millions—of years, depending on how many bits there are in the keys, says Bikash Koley, CTO for Juniper Networks. Quantum algorithms can break current security by reverse computing private keys in only days or hours.
In theory, however, quantum computers should be good at prime factorisation and therefore able to decrypt messages using only the public, and not the private, key. Mathematics that would take thousands of years on today’s technology could be reduced to hours on a quantum machine – and much of today’s security would be obsolete.
By harnessing quantum super-positioning to represent multiple states simultaneously, quantum-based computers promise exponential leaps in performance over today’s traditional computers. Quantum computers shall bring the power of massively parallel computing i.e. equivalent of a supercomputer to a single chip. They shall also be invaluable in cryptology and rapid searches of unstructured databases.
A quantum computer of sufficient size and complexity will be capable of executing Shor’s Algorithm, a proven algorithm that can break factorization-based encryption that would take a classical computer billions of years of computing time to complete. This advance puts all systems running public key, or asymmetric, cryptography at risk.
In 1994, Peter Shor of Bell Laboratories showed that quantum computers, a new technology leveraging the physical properties of matter and energy to perform calculations, can efficiently solve each of these problems, thereby rendering all public-key cryptosystems based on such assumptions impotent.
In the twenty years since Shor’s discovery, the theory of quantum algorithms has developed significantly. Quantum algorithms achieving exponential speedup have been discovered for several problems relating to physics simulation, number theory, and topology. Quantum computing is also believed to be capable of tackling other mathematical problems classical computers can’t solve quickly, including computing discrete logarithm mod primes and discrete logs over elliptic curves.
Shor Quantum algorithm threat to encryption
Since the quantum computers works differently than classical computers therefore, they require different software approach and different quantum algorithms. One of the famous algorithms is Shor’s algorithm that perform integer factorization in polynomial time compared to exponential time taken by best classical algorithm
Shor’s algorithm is a quantum algorithm that is specifically designed to break the commonly used RSA (Rivest-Shamir-Adleman) encryption scheme, which is widely used in online transactions, banking, and other secure communications. The RSA algorithm works by using the difficulty of factoring large numbers to secure data, but Shor’s algorithm can quickly factor large numbers using a quantum computer, making it much easier to break RSA encryption.
Shor’s algorithm essentially works by finding the period of a function. It does this by using a quantum computer to create a superposition of all possible inputs to the function, and then applying a quantum Fourier transform to measure the period. This allows the algorithm to factor the large numbers used in RSA encryption, breaking the encryption and potentially exposing sensitive information.
The impact of Shor’s algorithm on digital security could be significant. If a large-scale quantum computer is developed, it could potentially break many of the cryptographic algorithms that are currently used to secure digital infrastructure. This could have serious consequences for industries such as finance, healthcare, and government, where the confidentiality of data is critical.
In summary, the Shor’s algorithm is a quantum algorithm that could potentially break the commonly used RSA encryption scheme, which would have significant implications for digital security. To mitigate this risk, researchers are developing new quantum-resistant encryption schemes that can resist quantum attacks, even in the event that large-scale quantum computers become available.
According to Bart Preneel, professor of cryptography in Belgium: To crack a 1,024-bit encryption key, you need only 2,048 ideal qubits”. We saw earlier that error correction codes produce ideal qubit by linking tens of thousands of entangled physical qubits. Therefore, you need millions of physical qubits which means quantum computers will not be a threat to cryptography any time soon.
This advance will put all systems running public key cryptography at risk from key exchange to encryption to digital authentication methods. This would seriously compromise the security of our digital infrastructure including internet payments, banking transactions, medical and financial records, emails and even phone conversations.
Quantum computers have the potential to pose a significant threat to digital infrastructure.
Finally, the emergence of quantum computers also poses a risk to the confidentiality of sensitive data stored on traditional computers. Quantum computers can theoretically be used to break into encrypted data by reverse-engineering the encryption key. This could have severe consequences for businesses, governments, and individuals, as it could potentially allow attackers to steal sensitive information such as financial data, trade secrets, and personal information.
An attacker needs about the same time to break the system as it takes the user to run it,” says Dr Tanja Lange, chair of the Coding Theory and Cryptology group at Technische Universiteit Eindhoven. This would seriously compromise the confidentiality and integrity of our global communication digital infrastructure including securing our internet payments, banking transactions, emails and even phone conversations.
Another area of concern is the potential impact of quantum computers on the integrity of digital signatures. Digital signatures are used to verify the authenticity and integrity of digital documents and transactions, and they are based on mathematical algorithms that are currently difficult to break with classical computers. However, quantum computers could potentially undermine the security of digital signatures, which could have significant implications for digital identity and online trust.
Another area of concern is the potential impact of quantum computers on blockchain technology. Blockchains use complex mathematical algorithms to secure their networks, and while they are designed to be resilient to traditional attacks, quantum computing could potentially undermine this security.
It is worth noting that while quantum computers represent a significant threat to digital infrastructure, they are not yet a widespread reality. While researchers have made significant progress in developing quantum computers, they are still in the experimental stage, and it is likely to be many years before they become widely available. However, given the potential impact of quantum computing on digital infrastructure, it is important to start planning for this eventuality now.
If large-scale quantum computers are ever built, they will be able to break many of the public-key cryptosystems currently in use. Experts like Michele Mosca, co-founder of the Institute of Quantum Computing at the University of Waterloo (Canada), sees a chance of 50% that by 2031 quantum computers will be able of breaking RSA-2048 encryption—a scheme today regarded as secure. “
Quantum Computer Advancements
The power of quantum computers depends on the number of qubits and their quality measured by coherence, and gate fidelity. Qubit is very fragile, can be disrupted by things like tiny changes in temperature or very slight vibrations. Coherence measures the time during which quantum information is preserved. The gate fidelity uses distance from ideal gate to decide how noisy a quantum gate is.
We are now in era of Noisy intermediate-scale quantum (NISQ) in which quantum computers are composed of hundreds of noisy qubits that are not error-corrected. They Physical qubits are realized using superconducting Josephson junction qubits and the trapped-ion qubits. Other promising Qubits are Semiconductor based qubits; Topological qubits; and Photonic qubits.
Calculations using these noisy qubits can introduce errors and make long computations impossible. However, these computers still can demonstrate the advantages of quantum computing and various algorithms are being developed in disciplines such as machine learning, quantum chemistry and optimization.
For future fault-tolerant quantum computers Researchers have devised error-correction schemes such as surface code, that store data redundantly with information spread over tens of thousands of entangled physical qubits. These combined bits are collectively known as a logical qubit or perfect qubit. Previous research has found that a quantum computer with 300 perfect qubits could perform more calculations in an instant than there are atoms in the universe.
Osprey, the most powerful quantum computer in the world launched by IBM in November, operates with 433 qubits. IBM Osprey has the largest qubit count of any IBM quantum processor, more than tripling the 127 qubits on the IBM Eagle processor unveiled in 2021. This processor has the potential to run complex quantum computations well beyond the computational capability of any classical computer. For reference, the number of classical bits that would be necessary to represent a state on the IBM Osprey processor far exceeds the total number of atoms in the known universe.
Chinese team discovers new algorithms that could break encryption with less qubits
A Chinese team said its new algorithm could dramatically reduce the scale of a practical quantum computer required to break encryption to 372 qubits– even less than the most powerful quantum computer in the world, Osprey.
Mainstream encryption in use today may become vulnerable within years instead of decades after Chinese researchers proposed a new code-breaking algorithm to run on a small quantum computer built from technology already within reach.
Reports citing experts suggest that the latest claim by Chinese scientists has left senior security and quantum experts in the US concerned.
“It might not be correct, but it’s not obviously wrong. And there’s the nagging question of why the Chinese government didn’t classify this research,” American cryptographer Bruce Schneier said in a blog post.
Scott Aaronson, director of the quantum information centre at the University of Texas at Austin, said a major problem with the Chinese research paper was its failure to clarify the advantage of quantum technology over classical computers.
“It seems to me that a miracle would be required for the approach here to yield any benefit at all, compared to just running the classical Schnorr’s algorithm on your laptop,” Aaronson wrote in a blog post.
But some senior security and quantum experts in the United States have raised concerns as well as doubts about that claim coming out of China.
Mitigating the Quantum Computer threat
In summary, while quantum computers offer many exciting possibilities, they also pose significant risks to digital infrastructure. It is crucial that organizations and governments take steps to address these risks and ensure that their digital systems are secure and resilient to quantum attacks.
For now, quantum computers are not powerful or advanced enough to defeat today’s cryptographic protocols, but it is important to prepare for them.
Some experts even predict that within the next 20 or so years, sufficiently large quantum computers will be built to break essentially all public-key schemes currently in use. Researchers working on building a quantum computer have estimated that it is likely that a quantum computer capable of breaking 2000-bit RSA in a matter of hours could be built by 2030 for a budget of about a billion dollars.
“To factor [crack] a 1,024-bit number [encryption key], you need only 2,048 ideal qubits,” said Bart Preneel, professor of cryptography at KU Leuven University in Belgium. “So you would think we are getting close, but the qubits announced are physical qubits and there are errors, so they need about 1,000 physical qubits to make one logical [ideal] qubit. Qubits’ delicate quantum state can be disrupted by things like tiny changes in temperature or very slight vibrations, so it can require thousands of linked qubits to produce a single logical one that can be reliably used for computation. So to scale this up, you need 1.5 million physical qubits. This means quantum computers will not be a threat to cryptography any time soon.
Considering the fact that data needs to be kept confidential for 10 to 50 years, organizations should start planning to switch now. Therefore, regardless of whether we can estimate the exact time of the arrival of the quantum computing era, we must begin now to prepare our information security systems to be able to resist quantum computing.
Furthermore, the emergence of quantum computers will also require a shift in the way we think about cybersecurity. With the potential to break many of the cryptographic algorithms used today, traditional approaches to security may no longer be effective. Instead, organizations and governments will need to adopt a more dynamic and adaptive approach to cybersecurity, which involves continuously monitoring and updating their security protocols in response to emerging threats.
In conclusion, the emergence of quantum computers poses a significant threat to digital infrastructure, particularly in the areas of encryption, blockchain technology, and digital signatures. To address these threats, there is a need for continued research into the development of quantum-resistant cryptographic algorithms and security protocols, as well as a shift towards a more dynamic and adaptive approach to cybersecurity. While quantum computers are not yet a widespread reality, it is essential that organizations and governments start planning for their emergence now to ensure the security and resilience of their digital infrastructure.