6 ms·

Elephant in the room: Quantum computers will destroy Bitcoin

4 points by r33b33 2y ago

Someone had to say it. Maybe the current drop is normies finally waking up and realizing that extrapolated accelerating developments in quantum computers will break encryption used in Bitcoin within 5 years. It's also extremely naive to assume it will be easy to transfer a massive decentralized project to a post-quantum algorithm. Maybe new cryptos will be invented, but Bitcoin will not "retain value". Things that will retain value if the entire internet is broken due to rapid deployment of quantum computers will be: - Real estate - Physical assets (gold, silver, etc) - Physical stock certificates (printed on actual paper) - Paper money Since internet, cards, finance may just stop functioning one day as quantum computers break all encryption. Feel free to prove me wrong.

deleted 2y ago
[deleted]
nabla9 2y ago
Less than 9% of current Bitcoin supply using obsolete Pay-to-Public-Key (P2PK) method would be in danger. Instead of ranting in public maybe study subject like hour or so.
- r33b33 2y ago
  Please educate me how that is the case. It could derive private key from public key.
  - nabla9 2y ago
    Other methods don't reveal the key.
    - r33b33 2y ago
      What "other methods"?
      - nabla9 2y ago
        P2PKH,P2SH,P2WPKH,P2WSH,P2TR
        r33b33 2y ago
        > Spelunking for Bitcoin by generating all possible keys and checking their account balances is not prevented by PQ algorithms. And how will you solve this?
        nabla9 2y ago
        Quantum computers are not magic. Only quadratic speedup for most problems, like search. That's why hash functions with key size 256 or higher are safe, for example.
    - tromp 2y ago
      They at least reveal it when publishing a spending transaction, opening a roughly 10 minute window for finding the private key and publishing a double spend with a much higher fee to steal the funds.
mikeodds 2y ago
I think it’s the other way around. It’s naive to assume miners will not sufficiently coordinate to stop Bitcoin becoming worthless. They are all economically incentivised to keep the network continuing to function.
westurner 2y ago
There is a pending hard fork to PQ Post Quantum algorithms for all classical blockchains. There will likely be different character lengths for account addresses and keys, so all of the DNS+HTTP web services and HTTP web forms built on top will need different form validation. Vitalik Buterin presented on this subject a few years ago. Doubling key sizes may or may not be sufficient to limit the risk of quantum attacks on elliptical curve encryption algorithms employed by Bitcoin and many other DLTs. The Chromium browser now supports the ML-KEM (Kyber) PQ cipher. Very few web servers have PQ ciphers enabled. It is as simple as changing a text configuration file to specify a different cipher on the webserver, once the ciphers are tested by time and money. There are patched versions of OpenSSH server, for example, but PQ support is not yet merged in core there yet either. There are PQ ciphers and there are PQ cryptographic hashes. There are already PQ-resistant blockchains. Should Bitcoin hard fork to double key sizes or to implement a PQ cipher and hash? Spelunking for Bitcoin by generating all possible keys and checking their account balances is not prevented by PQ algorithms. Banking and Finance and Critical Infrastructure also need to upgrade to PQ ciphers. Like mining rigs, it is unlikely that existing devices can be upgraded with PQ software; we will need to buy new devices and recycle existing non-PQ devices. If banks are on a 5 year IT refresh cycle, that means they need to be planning to upgrade everything to PQ 5 years or more before a QC quantum computer of a sufficient number of error-corrected qubits is online for adversaries that steal cryptoassets from people on the internet.
- westurner 2y ago
  The market does not appear to cost infosec value, risk, or technical debt into cryptoasset prices. PQ or non-PQ does not predict asset price in 2025-02. Breach disclosures apparently hardly affect asset prices; which is unfortunate if we want them to limit their and our taxable losses.
  - r33b33 2y ago
    It's pricing it in now, with 2 week lag.
    - westurner 2y ago
tromp 2y ago
Only time will prove you wrong. Breaking secp256k1 requires thousands of logical qubits, in turn requiring millions of physical ones. I really don't expect to see that in the next 10 years.

4 points by r33b33 2y ago

deleted 2y ago

[deleted]

nabla9 2y ago

Less than 9% of current Bitcoin supply using obsolete Pay-to-Public-Key (P2PK) method would be in danger. Instead of ranting in public maybe study subject like hour or so.

r33b33 2y ago
Please educate me how that is the case. It could derive private key from public key.
- nabla9 2y ago
  Other methods don't reveal the key.
  - r33b33 2y ago
    What "other methods"?
    - nabla9 2y ago
      P2PKH,P2SH,P2WPKH,P2WSH,P2TR
      - r33b33 2y ago
        > Spelunking for Bitcoin by generating all possible keys and checking their account balances is not prevented by PQ algorithms. And how will you solve this?
        nabla9 2y ago
        Quantum computers are not magic. Only quadratic speedup for most problems, like search. That's why hash functions with key size 256 or higher are safe, for example.
  - tromp 2y ago
    They at least reveal it when publishing a spending transaction, opening a roughly 10 minute window for finding the private key and publishing a double spend with a much higher fee to steal the funds.

mikeodds 2y ago

I think it’s the other way around. It’s naive to assume miners will not sufficiently coordinate to stop Bitcoin becoming worthless. They are all economically incentivised to keep the network continuing to function.

westurner 2y ago

There is a pending hard fork to PQ Post Quantum algorithms for all classical blockchains. There will likely be different character lengths for account addresses and keys, so all of the DNS+HTTP web services and HTTP web forms built on top will need different form validation. Vitalik Buterin presented on this subject a few years ago. Doubling key sizes may or may not be sufficient to limit the risk of quantum attacks on elliptical curve encryption algorithms employed by Bitcoin and many other DLTs. The Chromium browser now supports the ML-KEM (Kyber) PQ cipher. Very few web servers have PQ ciphers enabled. It is as simple as changing a text configuration file to specify a different cipher on the webserver, once the ciphers are tested by time and money. There are patched versions of OpenSSH server, for example, but PQ support is not yet merged in core there yet either. There are PQ ciphers and there are PQ cryptographic hashes. There are already PQ-resistant blockchains. Should Bitcoin hard fork to double key sizes or to implement a PQ cipher and hash? Spelunking for Bitcoin by generating all possible keys and checking their account balances is not prevented by PQ algorithms. Banking and Finance and Critical Infrastructure also need to upgrade to PQ ciphers. Like mining rigs, it is unlikely that existing devices can be upgraded with PQ software; we will need to buy new devices and recycle existing non-PQ devices. If banks are on a 5 year IT refresh cycle, that means they need to be planning to upgrade everything to PQ 5 years or more before a QC quantum computer of a sufficient number of error-corrected qubits is online for adversaries that steal cryptoassets from people on the internet.

westurner 2y ago
The market does not appear to cost infosec value, risk, or technical debt into cryptoasset prices. PQ or non-PQ does not predict asset price in 2025-02. Breach disclosures apparently hardly affect asset prices; which is unfortunate if we want them to limit their and our taxable losses.
- r33b33 2y ago
  It's pricing it in now, with 2 week lag.
  - westurner 2y ago

tromp 2y ago

Only time will prove you wrong. Breaking secp256k1 requires thousands of logical qubits, in turn requiring millions of physical ones. I really don't expect to see that in the next 10 years.