Nobody really knows when Bitcoin (BTC) and other cryptocurrencies will be “vulnerable” to the threat from quantum computers, according to most experts in the field. Twitter and other social media users have been warning and reminding people that we should stay informed about the latest developments in quantum computing, so that we are as prepared as possible when they finally arrive.
The last Quantum Risk Assessment Report was released in April 2020 from the http://globalriskinstitute.org.
As mentioned in the report:
“Currently deployed cryptographic systems, which include public-key cryptography, hash functions, and ciphers, underpin the security of virtually all communication protocols over the internet and related tools.”
These tools include existing digital payments systems, Internet of Things (IoT) devices and applications, cryptocurrencies, and various other mechanisms, the report confirms.
As noted by the research report’s authors:
“Quantum computers threaten the security of the aforementioned systems, by completely shattering the security of public-key schemes such as RSA and weakening the security of the so-called symmetric schemes, such as the AES family of ciphers.”
However, the exact time at which the present computer and networking systems will become potentially vulnerable to “systemic” quantum attacks mostly depends on just how large of a quantum computation is required to break these systems, the researchers noted.
Systemic quantum attacks could also be carried out once the required resources are available, the research study reveals.
New techniques have been found by scientists which “significantly reduce the size of the quantum circuit required to attack public-key cryptosystems, in particular RSA.”
Under reasonable or realistic assumptions, the physical resources needed to break RSA-2048 in less than a day has now decreased by “two orders of magnitude (from 172 million physical qubits to 1.17 million physical qubits, a two-order of magnitude reduction),” the researcher report confirms.
The researchers note that the potential impact for public-key systems based on ECDH is also “substantial.”
The research paper notes that “for the curve NIST P-256, we show a reduction from 67.7 million physical qubits to only 7.43 million physical qubits, an order of magnitude reduction, in order to break the scheme in under 24 hours.”
The paper recommends “monitoring all … advances [in this field] … [because the researchers claim it’s of] … paramount importance and stresses the importance of preparing for migration to quantum-resistant cryptographic systems.”
(More details about the study are available here.)
In early 2019, expert cryptographer Adam Back had argued that quantum computers (QCs) would not be a threat to Bitcoin’s security as software architects will have developed quantum-resistant blockchains.
However, some researchers still believe QCs might become a legitimate threat to distributed ledger technology (DLT)-based cryptocurrencies.
IBM has already developed QCs that are ready to promote the “commercialization” of this technology, which could lead to vast improvements and advancements in “materials and drug discovery, financial services, and artificial intelligence.”
Distributed systems expert Andreas Antonopoulos claimed in early 2017 that the only real threat Bitcoin might face from quantum computers is if they’re available to just one individual or entity. He had argued that if QCs may be used by everyone, then all users will have the option of upgrading their computer systems together.
Back, the co-founder at Blockstream, had noted in early 2019:
“[Advancements in quantum computing is] cool news, but the very least of Bitcoins tech focus for this decade. [There are] quite a number of Bitcoin[-related] applied crypto[graphy] protocol developments [that are focused on creating] an opt-in signature scheme upgrade with Schnorr, aggregatable + space and verification cost signatures, and that [crypto developers] know how to phase in new signature schemes. [With that said,] Bitcoin can calmly & slowly watch quantum computing [make more advancements].”