4 ms·
Near the end of the post – after 50 years of axe grinding – djb does eventually get to the point wrt pqcrypto. I find the below excerpt particularly damning. Wh
by sigil 4y ago
Near the end of the post – after 50 years of axe grinding – djb does eventually get to the point wrt pqcrypto. I find the below excerpt particularly damning. Why not wrap nascent pqcrypto in classical crypto? Suspect!
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The general view today is that of course post-quantum cryptography should be an extra layer on top of well-established pre-quantum cryptography. As the French government cybersecurity agency (Agence nationale de la sécurité des systèmes d'information, ANSSI) put it at the end of 2021:
Acknowledging the immaturity of PQC is important: ANSSI will not endorse any direct drop-in replacement of currently used algorithms in the short/medium term. However, this immaturity should not serve as an argument for postponing the first deployments. ANSSI encourages all industries to progress towards an initiation of a gradual overlap transition in order to progressively increase trust on the post-quantum algorithms and their implementations while ensuring no security regression as far as classical (pre-quantum) security is concerned. ...
Given that most post-quantum algorithms involve message sizes much larger than the current pre-quantum schemes, the extra performance cost of an hybrid scheme remains low in comparison with the cost of the underlying post-quantum scheme. ANSSI believes that this is a reasonable price to pay for guaranteeing an additional pre-quantum security at least equivalent to the one provided by current pre-quantum standardized algorithms.
But NSA has a different position: it says that it "does not expect to approve" hybrids. Publicly, NSA justifies this by
- pointing to a fringe case where a careless effort to add an extra security layer damaged security, and
- expressing "confidence in the NIST PQC process".
Does that mean the original NISTPQC process, or the current NISTPQC process in which NIST, evidently surprised by attacks, announced plans to call for new submissions?
Of course, if NSA/IDA have secretly developed an attack that works for a particular type of post-quantum cryptosystem, then it makes sense that they'd want people to start using that type of cryptosystem and turn off the existing pre-quantum cryptosystem.
- tptacek 4y agoThis is the least compelling argument Bernstein makes in the whole post, because it's simply not the job of the NIST PQC program to design or recommend hybrid classical/PQC schemes. Is it fucky and weird if NSA later decides to recommend against people using hybrid key establishment? Yes. Nobody should listen to NSA about that, or anything else. But NIST ran a PQC KEM and signature contest, not a secure transport standardization. Sir, this is a Wendy's.
- sigil 4y agoIt’s compelling in context. If the NSA influenced NIST standards 3x in the past — DES, DSA, Dual EC — then shouldn’t we be on high alert this 4th time around? That NSA is already recommending against hybrid, instead of waiting for the contest results, might signal they’ve once again managed to game the standardization process itself. At the very least — given the exhaustive history in this post — you’d like to know what interactions NSA and NIST have had this time around. Thus, djb’s FOIA. And thus the lawsuit when the FOIA went unanswered. It all seems very reasonable to me. What’s that old saying, “fool me thrice…”?
- tptacek 4y agoEverybody is on high alert. Being on high alert doesn't make Bernstein right. I don't even support the premise of NIST crypto standardization, let alone trust them to do it.
- blueprint 4y ago> Everybody is on high alert. Being on high alert doesn't make Bernstein right. What exactly are you arguing for, with this? Pretty sure the dude you're replying to knows about the existence of cognitive biases, thanks.
- tptacek 4y agoIt's pretty obvious, right? What Bernstein is saying here can (and probably is) a load of horseshit, and it's still a terrible idea to trust NIST. Seems like a simple argument.
- blueprint 4y agoUh, would you take your simple argument and give me even a single sentence pointing out proof or clear indication it's horseshit. So far I only saw you arguing over words mostly