I've factored the RSA keys of a Certificate Authority from the 90s
mcpherrin.ca
mcpherrin.ca
Just to reply to some people in the comments. Yes, we knew export grade encryption was weak - that was the point - that the NSA could decrypt it - and the govt. required us to do it anyway.
FWIW - we had the goal of expanding the list of root authorities in the 4.5x release - and this might have been the first release to monetize the root slots because Netscape was under severe pressure to generate revenue.
(Also - Verisign hated that we were expanding competition and tried to convince us to implement a program that would re-restrict the list to a set of "responsible" companies aka Verisign and one or two others. We declined.)
Suppose you live in South America, register a domain from a registry in Canada and then have users accessing it from Ukraine. Are we going to give every local government a global root certificate? Have a single one in California or Texas that every other country is somehow forced to use? Or make it so people in Europe can't access sites in Asia and vice versa?
The existing system is more than the usual amount of messed up but that seems like one of the things that could actually make it worse.
Just publish a public key in your DNS TXT records. ACME is just that anyways but with extra (pointless) steps.
The whole SSL certificate grift is just a way to extort money out of nothing.
DNSSEC is probably not even used, though I never checked.
Eg. as a domain owner, you will put a cryptographic hash into your DNS zone so a CA can validate you have control over it, and then issue a different cryptographic hash derived from their private key, and browser will use their public key to validate this cryptographic hash (TLS cert) is valid.
So we could simply push public key into a DNS zone, and browsers could use it to decrypt the traffic encrypted by the private key from the server hosted under that DNS name: no CAs needed, similar to SSH except the DNS-ownership-implied-trust component.
"Extended validation" certificates involved a lot more (in theory, checking true ownership, business address, physical presence, etc), but nobody really cares about these, and with the push to automated renewal and 45-day expiration dates by 2028, it's going to make even less sense.
Edit: I realize now that you may be referring to the fact that MITM DNS server can inject a different public key in there and thus DNSSEC is required — you are absolutely right, and this is a good and important point.
After that, open source efforts to rebuild the entire browser and mail client took years as XUL and Gecko were being built as very generic reusable components, opening up the space for competition to spring up. On top of that, Microsoft leveraged the Windows moat, including IE 3.0 and later 4.0 as the basis of Windows "97" (95 something-something) and 98, along with ActiveX push. By the time legal systems caught up with the practice of bundling a browser into a dominant OS, Netscape and Mozilla were toast.
Everything from there on was an uphill battle, and when KHTML was turned into WebKit by Apple, and adopted by Google for Chrome, there was also an open source engine (or two) supported by infinite money.
That's at least how I remember it, but you are welcome to fact-check me on any of those since this is now 20-30 years ago.
These days with the CA/Browser forum, CCADB, and openly run root programs from Mozilla, Chrome and others, this is all much better documented than what went on in the early days, so I definitely have some strong historical interest in what came before.
Update: found this explanation in a comment at the top of the (surprisingly short) Go file in the linked repo:
The target client is Netscape Communicator 4.51 (both the 40-bit export build and the 128-bit US build) with its clock set to the year 2000.
Go's crypto/tls cannot help: it dropped SSLv3 in Go 1.14, never accepted the SSLv2-compatible ClientHello that Netscape 4 sends, and never had RC4-MD5 or the 40-bit export suites. So this file carries its own tiny SSLv3 server-side implementation on top of stdlib primitives (RSA PKCS#1 v1.5, RC4, DES, 3DES, MD5, SHA-1). The server key is 512-bit RSA so that export clients can encrypt the premaster secret to it directly, without a ServerKeyExchange.
I've written and worked on a few TLS implementations, so it wasn't terribly interesting to me. And I have to go to work tomorrow and solve real, modern CA problems :)
But in short, I wanted to use Go, and it doesn't support SSLv3, the SSLv2 Client Hello, or the 40-bit RC4-MD5 export-grade cipher suites which I wanted to support too.
I was more shocked that I managed to get stock OpenSSL to issue a certificate that worked. There's a number of things that didn't work there, too. You can find my scars in mkcert.sh in the repo. Perhaps all of this is worthy of a follow-up post.
I could have tried to get some old server running instead, but I wouldn't have wanted to deploy that on the internet, even on an isolated Fly VM.
From my prospective, the outputs of a bot aren’t the interesting bits, it’s the input prompt that should warrant more attention.
Since inputs are more interesting than outputs I've included my prompt; you should submit it to your AI to see why you're wrong.
> I'm debating with someone online. Can you come up with a counter argument? Here's what they said: <QUOTE>
They used a similar kind of custom (and flawed) TLS implementation in their game(s) which allowed signing new certificates after brute forcing.
The benefit to this is that users can now play these games without needing to burn a new CD with either the SSL certs swapped, or the code patched to dummy out the checks. A "retail CD" will simply work with private servers now.
I've also been on the other side of the fence, building a "retro internet" service [1] has meant trying to implement ancient SSL/TLS services for things and people that want to use them on the network.
Getting modern OpenSSL (aka what ships in Debian) to even accept these ciphers, let alone keys that short is an uphill battle. Understandably, they're disabled by default and (in Debian at least) the cipher support isn't even compiled into the binary! This requires building a custom OpenSSL to build Nginx against to serve ancient SSL.
Presumably for the OP this kind of work was either outside of their realm of knowledge, or simply "easier" to outsource to the slop machine. Though I hope the machine they're running their demo TLS implementation on is separated completely from their own network. Rolling your own crypto libraries is always a bad idea [2] and I doubt LLM's have "improved" that
[1] https://www.youtube.com/watch?v=cSJsGNIDjtc
[2] https://soatok.blog/2025/01/31/hell-is-overconfident-develop...
When you outsource to the slop machine, you don't have anything interesting to say (usually).
I will say that my projects have a "leading the pack" anti-AI policy [1]
“Presumably for the OP this kind of work was either outside of their realm of knowledge,”
Unnecessary? I don’t even follow the statement’s framing even if I validated the apparent nerdswipe tendency.
It's okay to "not know things". Computers are such an incredibly vast field that there's chunks of them that can simply be beyond some of us
Absolutes like this aren’t absolutely true.
It’s interesting because in a related comment, someone claimed that I was “rolling my own crypto” https://news.ycombinator.com/item?id=37368245
>>>a few odd coding decisions, such as rolling your own crypto (RNG)<<<
Let me give some context here. MaraDNS is a DNS server that’s been around for a very long time, since 2001. There has never been, in those 25 years, any security holes found having to do with the RNG code used by MaraDNS. MaraDNS originally used an AES variant for the RNG; when DJB found cache timing attacks a little over two decades ago, I revised the AES-based RNG code to minimize the impact of such impacts, making the code slower and more complicated. So, about two decades ago, I implemented a new RNG based on RadioGatún, an algorithm which isn’t vulnerable to cache timing attacks and, indeed, has no known attacks which break its cryptographic claims, even though those claims were made over two decades ago.
My code has been extensively audited by multiple AI-based security researchers, and while they found two minor issues with the DNS-over-TCP code in the recursive resolver, and a minor issue with the RFC8482 reply in the recursive resolver, no issues have ever been found with the RNG code in MaraDNS (except the issue with possible cache timing attacks I fixed myself after learning about them). [1]
In the same time period, OpenSSL has had a large number of security issues, security advisories, and so on. OpenSSL has had countless security holes and patches in the last two decades (Heartbleed, etc.); MaraDNS has had precisely 0 known issues with its RNG code in the same time period. If I had relied on OpenSSL to keep MaraDNS’s cryptography secure, it would had been exposed to many more attacks than it has, since the code I rolled myself ended up being far more secure than using the code in a third party library.
Point being, it is possible for someone to roll their own secure RNG. I wouldn’t do so in a corporate context, for the simple reason management often times puts unreasonable time constraints on developers, but for an open source project developed on my own timeline, it can be, in fact it has been very secure.
Also: I was never exposed to the Lastpass breach because, instead of using Lastpass, I rolled my own secure website password generator. [2]
The advantage of using a cryptographically secure stream cipher [1] is that we only need about 128-256 bits of good entropy to generate an arbitrary large number of secure random numbers, across multiple systems (e.g. MaraDNS has a native Windows port where /dev/urandom randomness is instead done with proprietary Windows API calls). It can even give us some level of protection on systems where the OS level random API is compromised: Some people are wary of RDRAND because they think Intel might actually use an insecure PRNG for the numbers, and Coldcard Bitcoin seed generators were compromised a little over a month ago because their version of /dev/urandom was completely insecure on some of their devices.
[1] Yes, libsodium supports them: https://libsodium.gitbook.io/doc/advanced/stream_ciphers
The application domain where this tends to get brought up as a problem is in large-scale simulation. I have no opinion about whether getrandom is fast enough for simulation, but here we're talking about cryptographic random numbers, not simply high-quality random numbers. If you want to use something like PCG for your simulations I won't dunk on you.
getrandom() is another possible solution, but the problem with getrandom() is that it’s also not part of the POSIX spec, and my program needs to compile in an anally POSIX compliant system: While my programs use chroot() and setgroups(), both of which aren’t part of the POSIX spec, it has a configure time option to disable both chroot() and setgroups() so everything will compile as long as the underlying system follows POSIX.
The reason for this strict compliance with POSIX is because the changes to the C compilers (gcc and clang) between 2022 and 2026 made previous versions of MaraDNS have issues compiling everything, and, indeed, with these C23 changes to C compilers, unpatched djbdns no longer even compiles with a modern compiler. I changed everything to work with the new C23 spec, then I changed the compile flags to compile with a strictly compliant C99 compiler, but to get that to work, I had to make the program strictly POSIX compliant (with the exceptions of chroot() and setgroups()).
This way, should MaraDNS not compile in the future (remember: The post-C23 changes broke a lot of programs that used to compile just fine), it’s a bug with the compiler not following C99 and/or POSIX, and not a bug with MaraDNS.
Hence, my homegrown secure pseudo random number generator, so I can make strong random numbers while remaining POSIX compliant (we seed the PRNG before entering the chroot() sandbox). Of course, /dev/urandom is also not part of POSIX, but it’s on pretty much any modern *NIX, and trying to open /dev/urandom is not going to raise compile-time errors.
Is there anything published online about this? It looks like the Sylverant website still requires patching the game.
The CADO-NFS page gives some benchmark results for 16 threads, suggesting the algorithm parallelises at least somewhat well.
Looks like 70% of cloudflare requests are using post-quantum TLS! https://radar.cloudflare.com/post-quantum
The idea would be to use an existing connection (established via normal TLS) to agree upon and exchange a pre-shared key. For subsequent connections, that key would be incorporated as one extra input to the key derivation function, and a new key would be derived.
This would make TLS more secure against adversaries who can break asymmetric encryption (now or later) and monitor some of your communications, but who do not have access to all of your communications. If you managed to get on an unmonitored network even once (foreign hotel WiFi, coffee shop without a wiretap), and securely establish a PSK there, all future interactions would be inaccessible to an adversary who can't break symmetric crypto.
Probably not too many, because anonymous political speech from 10+ years ago isn't that interesting. Punishing people a decade after the fact isn't very effective for anything.
It sends a very clear message: even if it takes a decade, we will find you and punish you.
There was a project in 2021 to talk to the banks and brokers that we connected and ask them to upgrade their keys and ciphers to modern versions.
IIRC, the oldest key/cipher was from the late 2000s so it wouldn't surprise me if someone is using RSA keys from the 90s somewhere.
You can read more about how hedge funds use FTP here: https://x.com/alexpotato/status/1809579426687983657?s=20
Or listen to patio11 and I talk about these systems in general here: https://www.complexsystemspodcast.com/episodes/two-banks-can...
Nothing like being on-call when the file doesn't get delivered, or fails to parse
Fortunately most feeds deliver reference data inband these days
I guess in some ways this is better but SWIFT is famously a giant pain in the ass to install and support.
> The Web PKI deprecated 1024-bit RSA over a decade ago, and while I don’t know of anyone factoring a key of that size, it’s within the realm of possibility for a government or other organization with a large number of computers.
Is it? How do I verify such claim?
---
> Just a few days ago, someone factored the 862-bit RSA-260 key from the RSA factoring challenge.
Yeah, but how much time it required? and what about the resources? It is just a number, it is not all the 861 bits n numbers.
A Cost-Based Security Analysis of Symmetric and Asymmetric Key Lengths https://cr.yp.to/bib/2000/silverman.pdf
It was a response to the idea that 1024 bit RSA was under threat at the time.
The security of RSA however depends on the factoring of very large numbers, and that means that for example, RSA-2048 doesn't translate into 2048 bits of security but 112 (roughly symmetric equivalent) bits based on the best factoring algorithms (for comparison, the RSA-512 the article mentions has an 56 bit equivalent and RSA-1024 has a 80 bit equivalent security, so RSA-1024 would take roughly 2^(80-56) ~= 17 million times to compute the worst-case scenario and RSA-2048 would take 2^(112-80) = 4.3 thousand million times more).
According to the Wikipedia article on RSA numbers, RSA-220 (66b) was factored in 2016, RSA-230 (69b) in 2018, RSA-240 (72b) in 2019 and RSA-260 (76b) this year, which is too close to RSA-1024 (80b) to be comfortable.
For RSA-250, the team reported it took "roughly 2,700 core-years, using Intel Xeon Gold 6130 CPUs at 2.1 GHz.". I am not going to (or feel qualified to) make estimates of how that would translate to RSA-1024, but it does sound plausible given enough resources.
Consider it broken already for AI or NSA guys
> How do I verify such claim?
Step 1: Become a cryptography expert. ;)
What better reason is there to do something than it being fun?
It's essential that you do, because generating pretty plausible outputs is an LLM's bread and butter. Otherwise, only the one that you actually tested should be expected to be correct.
The biggest thing I'm afraid of is that the generated scripts missed some entries, or otherwise mis-classified them, in particular whether it got the trust bits right for each root. I would put the chances of that having some errors relatively high.
But there's too many roots across too many browser installers, so I'm not going to confirm the Netscape UI matches what the extracted data says.
Consumer hardware doing it in a couple of days in 2025 is roughly in line with Moore's Law extrapolations people were drawing at the time. The surprise isn't really the timeline. It's that someone did it as a weekend project rather than a nation-state effort.
PGP (1991) was considered secure as it was considered not brute forceable. With 128 bits, it was considered military grade at the time and the US had an export restriction due to that. That might have been an incentive for GNU Privacy Guard. In France you had to give your private key to the government authority if an encryption system used anymore than 56 bits (as I recall, I don't remember the exact number).
When a research team actually factored RSA-155 in August 1999, it took 8,400 MIPS-years due to efficiencies discovered. It still took 35 CPU-years spread across a cluster of 300 fast SGI/SUN workstations and Pentium II PCs (400-500 MIPS each), crunching in parallel for seven months. https://cs.ccsu.edu/~pelletie/local/risks/cryptography/Facto...
Robert Silverman, a senior research scientist at RSA Laboratories, published an analysis projecting these new hardware requirements against Moore's Law. His expectation was that within 10 years (roughly 2009–2010), common desktop machines would possess the speed and memory necessary to handle a 512-bit factorization entirely on their own. https://cr.yp.to/bib/2000/silverman.pdf
And assuming about ((32x32 core-hours) / 8766 (hours/year)) x 45,000 = 5256 MIPS-years.
So within the order of magnitude of the 1999 factoring! Of course, the MIPS number is kinda made up, so
The planet has a lot of people.
Probably zero doing anything worth MitMing, though.
Install CADO-NFS per upstream directions.
Get the number you want to factor. I just did this in a python repl, something like:
from cryptography import x509
f = open("gold-server.pem", "rb").read()
print(x509.load_pem_x509_certificate(f).public_key().public_numbers().n)
Then pass it to CADO-NFS. The full invocation for the server root was:
./cado-nfs.py 10754123440737946604182274398563307850262685121187325065132187145895199633213947273310647001521000121802425390193123548314361970563322281259804690831526167 -t 32 --workdir /data/cert1
openssl rsa -in private.key -text -noout
prime1:
00:f7:5b:73:5c:13:9b:7b:70:58:36:22:d6:25:e6:
44:15:f3:f7:b3:18:c5:11:65:77:f2:85:af:cc:79:
fa:d2:bd
prime2:
00:d4:81:b4:f5:af:a8:56:0e:a3:34:c0:e3:e8:60:
fb:b2:96:83:e2:af:6d:d7:09:3f:37:2a:bf:31:32:
cf:92:63Remember, Shor is like a coded gate level algorithm expressed as sequences of interconnected stable QuBits. So, if you double the cost for each RSA bit you add, its not "nothing" in terms of how you wire the rig.
(not a cryptographer, or a QC person so I expect to be hit by a very cold but stable quantum clue-by-four shortly. Maybe they have to hit me 1 million times, to confirm I'm hit. Its statistics.)
Steve Weis, who has been doing RSA factoring on some large GPU clusters, estimates factoring 1024-bit RSA would take about 2000 GPU-years, which is well within the range of anyone with a serious budget.
Naively looking at scaling factors is going to be tricky, because computation of this scale is going to involve things like "how do I hijack every GPU on the planet", or worrying about when the sun will run out of hydrogen if you're using a single CPU.
says approximately the same as a 112-bit symmetric key, so 1/65536 as fast as however your target platform does at AES128, but probably 2000 times slower again because RSA is a really slow algorithm.
128-bit security is the de-facto minimum standard. Anything less than that is suspect. That's a 3072-bit RSA key. We only ever tolerated shorter keys because RSA is so slow. You should switch to ed25519 if you can.
2048 Bit RSA and the Year 2030 https://articles.59.ca/doku.php?id=em:20482030
We don't have any way to predict when and if 2048 bit RSA would be factorable at this time. We would need a breakthrough in hardware and/or algorithms. The common estimation that it is equivalent to the difficulty of brute forcing symmetrical 112 bit encryption seems to be based on some sort of straightforward extrapolation. It doesn't take into account the amount of memory required for the poorly reducible matrix reduction step in the currently known best algorithm. That's 10^18 bytes of memory, or a million terabytes, somehow coupled to enough processing power to actually make anything possible.
Even if you accept the 112 bit estimate, that works out to something like 400 thousand years using the Bitcoin network as a reference to what we could reasonably achieve.
I know that factoring (which attacks RSA) is sub-exponential, and I know that implementations of RSA (bad choices of primes, timing attacks, etc) can have weaknesses ... I'm just interested as to whether you have something else in mind.
Thx.
Reference to a scientific paper is given: https://www.ams.org/notices/199612/pomerance.pdf
I know there are other attacks on RSA, I was interested to know if the poster to whom I was replying knew of any others (other than factoring, which is kinda obvious). After all, I said:
> I know that factoring (which attacks RSA) is sub-exponential, ...
www.techtarget.com/cybersecurity/tip/The-ROCA-vulnerability-How-it-works-and-what-to-do-about-it%3famp=1
In practice it was confined to specific TPM modules, but in principle it shows how one flaw in the RNG can jeopardize the whole system.
I also remember seeing a similar vuln in certificates where an attacker _generated_ millions of certs and was able to somehow get the private cert by trying every possible seed for the RNG. (Like seeding every second from 2003-2011 for example, then generating a cert with it). I know I'm getting major parts of this wrong but it conveys the general idea.