top of page
Writer's picturemansour ansari

Post-Quantum Cryptography and blockchain

Will Quantinuum prevent hackers from breaking the blockchain?


What is blockchain technology?


Blockchain is a distributed ledger technology. The first era of the internet democratized the exchange of information. Blockchain, however promises to democratize the exchange of real value.

It goes back to the late 2008 era with the financial crisis of 2008. "Satoshi Nakamoto" released a new protocol for “A Peer-to Peer Electronic Cash System” and created a digital currency or cryptocurrency called Bitcoin based on blockchain technology, with the first Bitcoin transaction being realized on January 12, 2009.


Cryptocurrencies differ from traditional fiat money in that it is not issued by a national state. Bitcoins are not stored in a bank vault somewhere or a credit recorded in an electronic file somewhere; Bitcoin is a global spreadsheet or ledger of all transactions which leverages the resources of a large peer-to-peer network to review and approve each bitcoin transaction.

But blockchain is more than cryptocurrencies, blockchain has more applications, and investors realize commercial potential - money is flowing in at a fast pace.


This short blog post covers the work carried out by several companies working in collaboration to identify and eliminate quantum threats in blockchain networks. I read about them on Bloomberg News and then my research work began. These companies are:


  1. Cambridge Quantum Computing (CQC) - THEY CLAIM TO BE The World’s Largest Integrated Quantum Computing Company.

  2. The Inter-American Development Bank. The Inter-American Development Bank is the largest source of development financing.

  3. The IDB Lab, LACChain. LACChain. LACChain is a global alliance integrated by different actors in the blockchain environment and led by IDB Lab for the development of the blockchain.

  4. Tecnologico de Monterrey ? - I could not find any quantum cryptography related news on this company, but I am curious and I will update this post later.

  5. Quantinuum - https://www.quantinuum.com . A merger from Honeywell quantum systems and UK, Cambridge Quantum Computing systems. They claim to have the first quantum security solution for blockchain. I cover that in another post.

There is a looming threat -


The upcoming advancements in quantum computing threatens internet security protocols and blockchain networks because current blockchain technology lack quantum resistant cryptographic algorithms. When (unknown) these QCs become sufficiently powerful (error free - fault-tolerant ) to run Shor’s algorithm ( factoring large numbers named after Peter Shor. The algorithm is significant because it implies that public key cryptography might be easily broken) on a large scale, the most used asymmetric algorithms, will become open to hackers. Currently utilized for digital signatures and message encryption, such as RSA, (EC)DSA, and (EC)DH, blockchain will be no longer secure - that looks like a disaster waiting to happen, yet, completely preventable if the work done before a large-scale, fault-tolerant quantum universal quantum platform threaten the financial market. We may be few months or a few years away from reaching the point of no return!


Post-Quantum Cryptography Existing symmetric standards such as AES (The Advanced Encryption Standard ) believed in providing adequate security against the most capable classical adversaries, but any day, a capable quantum platform with just 1000 no noise perfect qubits can do just that in the matter of minutes if not seconds.


So, there is obvious concern that any day, a competent quantum computer with help from a classical computer together may be a threat, a capable adversary to the entire blockchain, financial market and quickly become a national security concern for any nation state.


Note: BC currently doesn't have any protection from a capable quantum platform. It is well known (by scientists) that public (asymmetric) key cryptographic protocols such as RSA , (Elliptic Curve) Digital Signature Algorithm , and (Elliptic Curve) Diffie-Hellman are considered vulnerable to quantum attacks. Post-Quantum Cryptography (PQC) refers to a new generation of asymmetric algorithms that cannot be broken by Shor’s algorithm. Unlike QKD, PQC does not rely on any underlying quantum processes but rather on more complex mathematical problems.


The main focus areas for postquantum algorithms to generate quantum-safe asymmetric key pairs are:


Hash-based Cryptography, based on the security of hash functions. Hash-based cryptography is the generic term for constructions of cryptographic primitives based on the security of hash functions. It is of interest as a type of post-quantum cryptography.

Code-based Cryptography, based on the difficulty of decoding generic linear code.

Lattice-based Cryptography, based on the difficulty of well-studied lattice problems For example, shortest vector problem. Lattice-based cryptography is the generic term for constructions of cryptographic primitives that involve lattices, either in the construction itself or in the security proof. Lattice-based constructions are currently important candidates for post-quantum cryptography.

Multivariate Cryptography, based on multivariate polynomials over a finite field. Multivariate cryptography is the generic term for asymmetric cryptographicprimitives based on multivariate polynomials over a finite field F.


I have included a downloadable PDF (below) that covers this new initiative in great detail. The Cambridge Quantum submitted a research paper that "identifies and eliminates" quantum threats in blockchain networks. They claim that "Only post-quantum keys, like Quantinuum’s pending announcement, will be able to protect these networks."


 

Quantum-resistance in blockchain networks

M. Allende1,2, D. L´opez Le´on1,2, S. Cer´on1,2, A. Leal1,2, A. Pareja1,2, M. Da Silva1,2, A. Pardo1,2, D. Jones3 , D.J. Worrall3 , B. Merriman3 , J. Gilmore3 , N. Kitchener3 , and S.E. Venegas-Andraca4 1 IDB - Inter-American Development Bank, 1300 New York Ave, Washington DC, USA 2LACChain - Global Alliance for the Development of the Blockchain Ecosystem in LAC 3Cambridge Quantum Computing - Cambridge, United Kingdom 4Tecnologico de Monterrey, Escuela de Ingenieria y Ciencias. Monterrey, NL Mexico


Resources:

"As with elliptic-curve cryptography in general, the bit size of the private key believed to be needed for ECDSA is about twice the size of the security level, in bits.[1] For example, at a security level of 80 bits—meaning an attacker requires a maximum of about 2^{80}operations to find the private key—the size of an ECDSA private key would be 160 bits. On the other hand, the signature size is the same for both DSA and ECDSA: approximately 4t} bits, where t} is the security level measured in bits, that is, about 320 bits for a security level of 80 bits."


Elliptic-curve Diffie–Hellman Elliptic-curve Diffie–Hellman (ECDH) is a key agreement protocol that allows two parties, each having an elliptic-curve public–private key pair, to establish 6 KB (892 words)

40 views

Comments


bottom of page