Thank you for the update. This is really useful. It would be really great, if you could commit to an update a few years down the road at the latest. E.g. "I will release an update no later than August 15th 2027". 3 years in the fast-changing world shouldn't be such a burden and it would help to settle many discussions somewhat reasonably with appeal to authority :-D No seriously, having something that can be considered current advice would be great.
Good list of early supporters near the bottom of the post text - Chrome, OpenSSH and iMessage are relevant for me.
As I understand it, the only reason pqc is of "practical" concern is the issue of "store now, decrypt later".
Is it possible to defend against this attack in a classical way? Some sort of time limit on decryption? Or an argument that it's impossible?
Excellent post, I've always recommended people to this series.
I'm curious what's the general opinion on the production-readiness of these solutions. Open Quantum Safe, for example, discourages it's use in production, and recompiling nginx to use PQC-BoringSSL feels risky since I'm not intimately familiar with both projects ("did I miss a --enable-security flag?").
> the PQ keys are 4 orders of magnitude larger
For McEliece, perhaps, but the algorithms in the tables are "only" 2 orders of magnitude larger.
“Classical cryptography” used to refer to historical ciphers, Vigenère and the like, tapering off after the World War 2-era cipher machines and definitely not used to describe asymmetric algorithms. There should be a different term for pre- (non-?) quantum cryptography from the modern era. We already suffered the redefinition of “crypto”.
NIST announcement:
* https://www.nist.gov/news-events/news/2024/08/nist-releases-...
See
* FIPS 203, Module-Lattice-Based Key-Encapsulation Mechanism Standard (ML-KEM / CRYSTALS-KYBER)
* FIPS 204, Module-Lattice-Based Digital Signature Standard (ML-DSA / CRYSTALS-Dilithium)
* FIPS 205, Stateless Hash-Based Digital Signature Standard (SLH-DSA / SPHINCS+)
From:
* https://csrc.nist.gov/News/2024/postquantum-cryptography-fip...
* https://www.federalregister.gov/documents/2024/08/14/2024-17...
Hostly, most cryptographic vulnerability today are because things are stuck in the NIST and FIPS regulation. Most vulnerable building blocks are still shipped to have their certification to begin with. Why there's still excitement to their work?
I've always found it a bit disquieting how many times people feel the need to update these "cryptographic right answers" blog posts.
This is what, a fourth or fifth version since 2009?
Meanwhile everything from ubuntu's apt-get to my connection to HN is secured with 2048-bit RSA - an algorithm invented in 1977 and in widespread use since at least 1995.
Am I getting crypto advice that will keep my data safe for 30+ years, if the advice changes every 3 years?
>Avoid: HMAC-MD5, HMAC-SHA1 and such. The underlying hash function has to be safe.
Interestingly enough, there is a proof out there that more or less states the opposite for HMAC-MD5 and HMAC-SHA1:
* https://eprint.iacr.org/2006/043.pdf
The issue here is that MD5 and SHA1 are broken for collisions. But no one could figure out an actual attack for HMACs based on them. The linked paper is an attempt to explain that.
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Great post! I was worried for a long time about this thing as I'm also working in DeFi field. It's great that governments are taking the quantum computer threat seriously
There are tables at the end describing the algorithms key sizes. be mindful of "(Size in bytes)" not bits. They cover that these algorithms use bigger keys, but it is 4 kilobytes.