Cryptographic Right Answers: Post Quantum Edition • Hacker News Board

Re: Cryptographic Right Answers: Post Quantum Edition

#11

Post by defrost » Thu, Aug 15, 2024, 10:35 AM UTC

michaelt wrote: post #8

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+ ye…

an algorithm publicly published in 1977.

The Ellis, Cocks and Williamson algorithm has existed since at least 1973.

Re: Cryptographic Right Answers: Post Quantum Edition

#12

Post by librasteve » Thu, Aug 15, 2024, 10:57 AM UTC

Good list of early supporters near the bottom of the post text - Chrome, OpenSSH and iMessage are relevant for me.

Re: Cryptographic Right Answers: Post Quantum Edition

#13

Post by Rhapso » Thu, Aug 15, 2024, 11:00 AM UTC

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.

Re: Cryptographic Right Answers: Post Quantum Edition

#14

Post by throw0101d » Thu, Aug 15, 2024, 11:03 AM UTC

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...

Re: Cryptographic Right Answers: Post Quantum Edition

#15

Post by Rhapso » Thu, Aug 15, 2024, 11:05 AM UTC

michaelt wrote: post #8

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+ ye…

On one side, there is good in "This is the best prediction of the future we have right now and we update it as our knowledge changes".

They also have a consulting product to sell you. When you build your entire society on "greed as a virtue", it is reasonable to assume it as a primary motivation for a profit seeking entity.

Re: Cryptographic Right Answers: Post Quantum Edition

#16

Post by [deleted] » Thu, Aug 15, 2024, 11:08 AM UTC

throw0101d wrote: post #14

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…

[deleted]

Re: Cryptographic Right Answers: Post Quantum Edition

#17

Post by ccppurcell » Thu, Aug 15, 2024, 11:34 AM UTC

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?

Re: Cryptographic Right Answers: Post Quantum Edition

#18

Post by kientuong114 » Thu, Aug 15, 2024, 11:37 AM UTC

michaelt wrote: post #8

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+ ye…

The right answer is not always about straight-out security: 2048-bit RSA is not broken and won't be broken for the foreseeable future, but we know that it is much less efficient and more error-prone than e.g. ECDH. So why suggest the former when the latter is a better alternative?

You should consider these "right answers" as if the question were, "I want to develop a new product today. What cryptographic primitive should I use?"

Re: Cryptographic Right Answers: Post Quantum Edition

#19

Post by candiddevmike » Thu, Aug 15, 2024, 11:39 AM UTC

ccppurcell wrote: post #17

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?

Sneakernet or OTP

Re: Cryptographic Right Answers: Post Quantum Edition

#20

Post by maxbond » Thu, Aug 15, 2024, 11:45 AM UTC

michaelt wrote: post #8

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+ ye…

> Am I getting crypto advice that will keep my data safe for 30+ years, if the advice changes every 3 years?

If you drill into the details a lot of things haven't changed. Eg, the key size and HMAC recommendations go back to the original version (among others).