SHA3-256 is quantum-proof, should last billions of years

Ye Olde hash standard looks like it can beat the coming of the quantum cats


Although it's reasonable to assume that a world with real quantum computers will ruin traditional asymmetric encryption, perhaps surprisingly hash functions might survive.

That's the conclusion of a group of boffins led by Matthew Amy of Canada's University of Waterloo, in a paper at the International Association of Cryptologic Research.

The researchers – which included contributions from the Perimeter Institute for Theoretical Physics and the Canadian Institute for Advanced Research – looked at attacks on SHA-2 and SHA-3 using Grover's algorithm (a quantum algorithm to search "black boxes" - Wikipedia).

They reckon both SHA-256 and SHA3-256 need around 2166 “logical qubit cycles” to crack.

Perhaps counter-intuitively, the paper says the problem isn't in the quantum computers, but the classical processors needed to manage them.

The paper notes: “The main difficulty is that the coherence time of physical qubits is finite. Noise in the physical system will eventually corrupt the state of any long computation.”

“Preserving the state of a logical qubit is an active process that requires periodic evaluation of an error detection and correction routine.”

If the quantum correction is handled by ASICs running at a few million hashes per second (and if Vulture South's spreadsheet is right), Grover's algorithm would need about 1032 years to crack SHA-256 or SHA3-256.

That's considerably longer than the mere 14 billion years the universe has existed, although less than the estimated 10100 years until the heat death of the universe. Even if you didn't care about the circuit footprint and used a billion-hash-per-second Bitcoin-mining ASIC, the calculation still seems to be in the order of 1029 years. ®

Similar topics

Broader topics


Other stories you might like

  • Protecting data now as the quantum era approaches
    Startup QuSecure is the latest vendor to jump into the field with its as-a-service offering

    Analysis Startup QuSecure will this week introduce a service aimed at addressing how to safeguard cybersecurity once quantum computing renders current public key encryption technologies vulnerable.

    It's unclear when quantum computers will easily crack classical crypto – estimates range from three to five years to never – but conventional wisdom is that now's the time to start preparing to ensure data remains encrypted.

    A growing list of established vendors like IBM and Google and smaller startups – Quantum Xchange and Quantinuum, among others – have worked on this for several years. QuSecure, which is launching this week after three years in stealth mode, will offer a fully managed service approach with QuProtect, which is designed to not only secure data now against conventional threats but also against future attacks from nation-states and bad actors leveraging quantum systems.

    Continue reading
  • D-Wave deploys first US-based Advantage quantum system
    For those that want to keep their data in the homeland

    Quantum computing outfit D-Wave Systems has announced availability of an Advantage quantum computer accessible via the cloud but physically located in the US, a key move for selling quantum services to American customers.

    D-Wave reported that the newly deployed system is the first of its Advantage line of quantum computers available via its Leap quantum cloud service that is physically located in the US, rather than operating out of D-Wave’s facilities in British Columbia.

    The new system is based at the University of Southern California, as part of the USC-Lockheed Martin Quantum Computing Center hosted at USC’s Information Sciences Institute, a factor that may encourage US organizations interested in evaluating quantum computing that are likely to want the assurance of accessing facilities based in the same country.

    Continue reading
  • BMW looks to quantum computers to speed R&D
    Pasqal to provide compute based on approaches by Qu&Co acquisition

    BMW has become the latest company to give quantum an early chance, with the goal of shrinking development cycles beyond traditional means.

    Quantum computing systems and software startup Pasqal announced that it is partnering with the German automaker, which will use the French biz's proprietary differential-equation-solving algorithm to test quantum computing's applicability to metal-forming modeling.

    BMW is experimenting with Pasqal's systems to reduce time spent building and testing physical models of metal components, which often have to be minutely tweaked after testing to achieve the results designers and engineers want.

    Continue reading
  • IBM: Give us three years to solve quantum computing scaling
    Big Blue claims it'll have a 4,158 qubit system by 2025

    IBM Think IBM has big plans for its quantum computing gambit, including the launch of a 4,158-qubit system by 2025. To put that in context, the company just launched it's 127-qubit "Eagle" system in 2021.

    The ambitious qubit count goal was presented at IBM Think 2022 during a tour of IBM's expanded supercomputing roadmap, which takes Big Blue through 2025, the year IBM Quantum VP Jay Gambetta said says "will have effectively removed the main boundaries in the way of scaling quantum processors." 

    IBM telegraphed its quantum computing plans in 2020 when it revealed its plan to design quantum computers that work with classical computers and interconnects to form one big datacenter style quantum system. 

    Continue reading

Biting the hand that feeds IT © 1998–2022