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Doesn’t this mean crypto has a major problem ?
by phas0ruk 3y ago
Doesn’t this mean crypto has a major problem ?
- was_a_dev 3y agoIn the realm of quantum computing, it always has
- aleph_minus_one 3y ago> In the realm of quantum computing, it always has No: https://en.wikipedia.org/wiki/Post-quantum_cryptography https://en.wikipedia.org/wiki/Post-quantum_cryptography
- adastra22 3y agoPQC is very immature.
- red_admiral 3y agoGenerally true, but Google has started using the stuff in production: https://cloud.google.com/blog/products/identity-security/why-google-now-uses-post-quantum-cryptography-for-internal-comms https://cloud.google.com/blog/products/identity-security/why...
- bawolff 3y agoBut its still bleeding edge. Its been used for experimental purposes but always in combination with a traditional algorithm (so if its broken the traditional algo still secures things). Its definitely not trusted yet.
- survirtual 3y agoYes, which is what google is doing if you read the blog post. They wrap PQC encrypted message with x25519.
- Aachen 3y agoI agree with you that the statement is overly broad, but the person is referring to asymmetric cryptography in the past tense, making me read it as not about PQC because PQC is indeed the fix for the stated problem but must be applied first and until then, indeed we've always known QC are going to be an issue that needs solving.
- was_a_dev 3y agoThank you, I did However I was also unaware of PQC, which has been an interesting rabbit hole for the day
- some_furry 3y agoSubtext: This is about quantum computers, which have been known to break RSA and ECC for the order of 30-ish years now.
- adastra22 3y ago*known to be able to No quantum computer has ever been used for that purpose in real life, however.
- bawolff 3y agoKind of goes without saying when nobody has built a quantum computer of the type we are talking about. No general purpose error corrected quantum computer has been used to do anything because they don't exist yet.
- Aachen 3y agoI don't think that's common knowledge. It's commonly accepted truth in the industry, but particularly when most people think of military/spies as secretly X years ahead (pick a number) of what the public knows is possible, the tech sector in general can't be expected to know this. It's good to add this in a thread with a headline that sounds like anyone using ecc keys might have a big problem.
- flangola7 3y ago>No general purpose error corrected quantum computer has been used to do anything because they don't exist yet. It isn't cryptographically relevant yet, but quantum supremacy was achieved in 2020: https://arxiv.org/abs/2012.01625 https://arxiv.org/abs/2012.01625
- less_less 3y agoI don't think that machine was either general-purpose or error-corrected though. IIUC we can build at most a few error-corrected gates right now.
- 3y ago
- NavinF 3y agohttps://pqcrypto.org/ https://pqcrypto.org/
- bawolff 3y agoSo its mostly just public-key encryption and its been a known issue since about 1994. We are still nowhere near making quantum computers that can crack them so its not an urgent thing. There has been a lot of research into alterantives though.
- wahahah 3y agoBeing able to crack present-day communications in the future is still a concern.
- its-summertime 3y agoHence https://en.wikipedia.org/wiki/Forward_secrecy https://en.wikipedia.org/wiki/Forward_secrecy to make things more difficult Compromising the main keys isn't enough, need to compromise each session key as well in turn, a massive increase.
- upofadown 3y agoForward secrecy does not provide any value against cryptography compromise. Quite the opposite as it depends on the security of the cryptography over the long term to insure old messages stay inaccessible after the key is forgotten. Forward secrecy addresses this specific attack: * Someone builds a archive of your encrypted messages, possibly without your knowledge or consent. * That someone then gets access to your secret key material. * They can then decrypt their archive. The session keys are exchanged by the asymmetrical systems that the imagined quantum computer would be able to break. So the attacker gets the session keys directly. So for, say, signal, they only have to break a new key exchange which doesn't happen all that often. They can just run the hash ratchet after that. Even for TLS that does a new session key per connection, that connection might last a fair time. The 10 min can be spread over multiple connections for this proposal. We are hardly talking about a massive increase of difficulty.
- bawolff 3y agoI mean, it depends a little bit on what your threat model is. If it takes a week to break a key, and you have hundreds of thousands of tls sessions without knowing which is the relavent one, it is definitely something. But yeah it seems like it would quickly become a minor hurdle once real quantum computers become a thing and presumably have their own moore's law.
- survirtual 3y agoEncrypted comms has a problem. Crypto does not, for a lot of reasons, but biggest I can think of is that hashing is still one-way, public keys are hidden (until used, which is why it is important to expose your public key only when using funds). When there is a viable ECC attack vector, it will not be much effort to migrate to a more mature PQC. Better to wait as long as possible, maybe even have a crypto built on PQC to field test it with money on the line -- a few billion in market cap goes a long way to incentivizing breaking the crypto involved.