8 ms·
… only if scalable quantum computers exist.
by ilya_m 2y ago
… only if scalable quantum computers exist.
- warkdarrior 2y agoIf scalable quantum computers do not exist, we do not need PQC.
- foota 2y agoHemomorphic encryption is not the same thing as post quantum crypto?
- deknos 2y agoHomomorphic Encryption does often use lattice mathematics
- Ar-Curunir 2y agoBut classically secure FHE is still a useful thing (even if it is broken by hypothetical quantum computers).
- Beldin 2y agoNo, they're orthogonal terms. Homomorphic encryption is encryption where a specific operation on ciphertexts (e.g., ×) translates into an operation on the underlying plaintexts (e.g., +). With fully homomorphic encryption, there are even two such ciphertext operations (and corresponding plaintext operations). Post quantum crypto is cryptography that cannot be broken by a quantum computer. This is rather nebulous, since we haven't yet discovered all possible algorithms that can run on quantum computers. Before you know it, someone comes along and finds a new efficient algorithm for quantum computers that breaks something thought to be post-quantum. Which is what is happening here - if the results stand up under scrutiny. Sidenote: it may turn out that any crypto scheme which supports some operation on ciphertexts that translates into an operation on the plaintexts is quantum-resilient (or, vice versa, quantum-vulnerable). But tgat would require a fornal proof.
- sgt101 2y agoWe need PQC about 20 years before practical, scalable gate quantum computers appear (if they can do all the right gates). I think that this will be signaled when someone factors a 32 bit integer on one. At that point I guess it'll be about 20 years before someone can factor a 2048 bit integer, and I'll get twitchy about what I am sending over the wire with PKI. My feeling is that all my secrets from 20 years ago are irrelevant to life now so I feel 20 years of warning is quite sufficient.
- adastra22 2y agoWe are within 20 years of scalable quantum computers already.
- adrianN 2y agoThe record for integer factoring on quantum computers was on the order of factoring fifteen into three times five the last time I checked. Can we do three digits now?
- baby 2y agoThe last time I checked they even cheated to factor fifteen
- WJW 2y agoYou should check again. Numbers like 1099551473989 have been factored successfully by now. The arxiv link in the sibling post is a good start.
- adgjlsfhk1 2y agobiggest number factored by a quantum computer isn't the right question. the right question is biggest number factored using a polynomial time algorithm. the answer to that as far as I know of still 15 (although I would be interested in papers that show more progress)
- Ar-Curunir 2y agoFHE is still only known from lattices, and has nothing to do with post-quantum computers.
- odyssey7 2y agoI wouldn't bet against the existence of a modern Bletchley Park analogue.