371–380 of 433 posts
Of course, if you can modify the SPF records, you can make the DMARC record say whatever you want.
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What's the problem with verifiable email? You can just delete old emails (if gmail or whoever archives them that's another problem). Most people probably operate under the assumption that email is verifiable in some way anyway. If you receive malicious email, isn't it a good thing to be able to verify where it came from? Doesn't that benefit senders and receivers alike? Or is this a case of "I want to verify you, but…
It's more "I want you to be able to verify I sent an email to you, but I don't want you to be able to prove to a third party that I sent it." The fact that this is possible is some cryptography black magic.
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Oh, great to know. That gives me hope that we'll see Ed25519 certificates at some point then.
THE CABForum just updated its guidelines (in December) and elliptic curve wise only NIST P-256, NIST P-384 and NIST P-521 are accepted. (See https://cabforum.org/working-groups/server/baseline- requirements/requirements/#615-key-sizes) So on the general web it seems remote at best.
NIST P-curve certs were acceptable per the Base Requirements all the way back in 2012
* https://cabforum.org/uploads/Baseline_Requirements_V1_1.pdf
See "Appendix A - Cryptographic Algorithm and Key Requirements (Normative)", (3) Subscriber Certificates.
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> (you can't just square amounts of money, just consider how it would work if you changed currency: $8 is 1260¥, squares it makes it 1587000¥ which is $10k != $64) What can you square then? For example, can you square lengths? E.g. 1km is 1000m, what is its square?
1km² aka 1,000,000m², note how the resulting units aren't km and m but square kilometers and square meters. > What can you square then? In that case it's the number of operations (which is unitless) that must be squared and then multiplied by the cost of each operation. For instance (figures are completely made up for illustration purpose) if one individual operation costs 0.1 cent, and you have 8000 ops for the fact…
(p1^2) x (p2^2) = (p1xp2)^2 =cost^2
and gnfs search cost increases in cost by (roughly) the square of the number of bits.
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It'd be funny if we were working together and just telling the same story behind our aliases.
My case was a family court dispute where one parent forged an email from the other parent about the child's care. It was a pretty wild case. After that, I was pretty convinced some people are just evil.
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I personally factored 512 bit numbers in 2007 for a lot less than $8, so tbh I'm going to say your overestimation of your knowledge of cryptology is far more hilarious than my paranoia about the potential truth of claims made by people claiming to be experts in cryoptology. Your claim that factoring a 256bit number would cost fractions of a cent rather than my claim of roughly $3 is also very easily verifiable. Furth…
I'm charitably sharing this to you: https://news.ycombinator.com/item?id=42645216 because someone actually interested in learning things asked the right question. May you sleep less ignorant tonight. > Further I'll note you sound exactly like the kind of person insisting diffie hillman was a good key exchange mechanism prior to Snowdens disclosures. good luck with that. Before or after Snowden, Diffie-Hellman (it's M…
Meanwhile, ~10 years ago https://weakdh.org/imperfect-forward-secrecy-ccs15.pdf
After a week-long precomputation for a specified 512-bit group, we can compute arbitrary discrete logs in that group
in about a minute.
We find that 82% of vulnerable servers use a single 512-bit group, allowing us to compromise connections to 7% of Alexa Top Million HTTPS sites. In response, major browsers are being changed to reject short groups. We go on to consider Diffie-Hellman with 768- and 1024-bit groups. We estimate that even in the 1024-bit case, the computations are plausible given nation-state resources.
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I forget where but someone proposed regularly rotating your DKIM key and publishing old keys for deniability. So you can still use strong keys and provide a level of deniability.
I've been doing this since around 2018, and have seen a few others implement it. https://rya.nc/dkim-privates.html
Sometimes you've just gotta love those auto-shortened URLs: security.googleblog.com/2013/12/internet-wide-efforts-to-fight-email.html
Hopefully one day we'll win the fight.
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Old but still relevant: https://www.schneier.com/blog/archives/2009/09/the_doghouse_... These numbers have nothing to do with the technology of the devices; they are the maximums that thermodynamics will allow. And they strongly imply that brute-force attacks against 256-bit keys will be infeasible until computers are built from something other than matter and occupy something other than space. Long story short, brut…
That’s true for AES-256. But brute force attacks are not the most efficient way to attack RSA, so it’s not true in that case. (Eg quantum computers would break RSA-4096 but not AES-256).
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That’s true for AES-256. But brute force attacks are not the most efficient way to attack RSA, so it’s not true in that case. (Eg quantum computers would break RSA-4096 but not AES-256).
Grover’s algorithm could be described as quantum brute force that is able to break AES-128 but not AES-256
Breaking a 512-bit key for a good demonstration is very valuable security research, even if it's been done before. It's also legit to call out "Hey, here's a list of folks still using 512 bit, they should move off." ... but for me, actually cracking a real-world in-use key crosses an ethical line that makes me uncomfortable. IANAL but it might even be criminal. Just seems a bit unnecessary.
They only called out 1 out of the ~1.7k domains they found with keys shorter than 1024bits. They _did_ call out the 3 of 10 tested major email providers that don't follow the DKIM RFC properly: Yahoo, Tuta, Mailfence (after having notified them).
Matthias, co-founder of Tuta Mail