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Notice they used only 760 bit RSA and it only has to be factored once. Then you can brute force the remaining 40-bit keyspace with GPUs.
I was under the impression that the NSA created a public/private key pair and gave this public key to Lotus Notes to use.
There was also a key marked as 'NSAKEY' in a normally encrypted part of Windows NT that was revealed in a Service Pack. However Microsoft said it had another purpose. http://en.m.wikipedia.org/wiki/NSAKEY
I don't have the reverse engineering skills/IDA Pro license to verify this, but fwiw I trust and respect this person's skills.
But lets do a thought experiment.
1. How much would the NSA gain from pressuring Microsoft into backdooring (or as they say, "enabling") Windows, in terms of systems they could not access before that they can access now?
2. How much would it cost the NSA, in terms of effort, good will, and exposure to risk by the people at Microsoft who would know about the backdoor and may leak or abuse it? How bad would it be if the public got wind of it? How hard would it be to keep it secret over the years, especially as engineers moved around to other companies? Would they have to involve foreign nationals on the dev team? Could they be trusted not to warn their governments?
3. How many times could they abuse their backdoor before it was obvious Windows couldn't be trusted? When/if that happened, what would be the damage to the US economy, and to their ability to penetrate systems?
When I put myself in the shoes of DIRNSA and ask myself these questions, backdooring Windows (at least through official channels, like _NSAKEY supposedly is) seems like an insane proposition.
Earlier quoted context omitted.
It is stronger than the 512-bit RSA factored in the FREAK attack but is still factorable with clusters. I wonder how fast a FPGA would be able to do it.
FPGA are very very inefficient at doing anything, they are very flexible and you can program them to perform specific operations very quickly relative to general purpose hardware however most of the silicon is dedicated to facilitate the programmability of the FPGA rather than the actual processing. If you only have access to commodity hardware than GPU's would probably be better. Xeon Phi is also insanely cheap righ…
tptacek said it's extraordinarily unlikely NSA can scalably factor RSA-1024 today [1].
Look at how difficulty increases in the Yafu with GGNFS benchmark on wikipedia [2].
1 - https://news.ycombinator.com/item?id=8844239
2 - https://en.wikipedia.org/wiki/RSA_%28cryptosystem%29#Integer...
Notice they used only 760 bit RSA and it only has to be factored once. Then you can brute force the remaining 40-bit keyspace with GPUs.
Are you saying that the NSA would have to brute force this public key? I was under the impression that the NSA created a public/private key pair and gave this public key to Lotus Notes to use.
There was also a key marked as 'NSAKEY' in a normally encrypted part of Windows NT that was revealed in a Service Pack. However Microsoft said it had another purpose. http://en.m.wikipedia.org/wiki/NSAKEY
Earlier quoted context omitted.
FPGA are very very inefficient at doing anything, they are very flexible and you can program them to perform specific operations very quickly relative to general purpose hardware however most of the silicon is dedicated to facilitate the programmability of the FPGA rather than the actual processing. If you only have access to commodity hardware than GPU's would probably be better. Xeon Phi is also insanely cheap righ…
Factoring RSA-2048 in 2020 sounds impossible. tptacek said it's extraordinarily unlikely NSA can scalably factor RSA-1024 today [1]. Look at how difficulty increases in the Yafu with GGNFS benchmark on wikipedia [2]. 1 - https://news.ycombinator.com/item?id=8844239 2 - https://en.wikipedia.org/wiki/RSA_%28cryptosystem%29#Integer...
Also, there's the possibility that even if a product uses a 2048 bit RSA key it might have been weakened.
"As of 2010, the largest factored RSA number was 768 bits long"
I read this as "today, 1024 bit factorizations are possible"
There was also a key marked as 'NSAKEY' in a normally encrypted part of Windows NT that was revealed in a Service Pack. However Microsoft said it had another purpose. http://en.m.wikipedia.org/wiki/NSAKEY
A buddy who is an excellent reverse engineer assures me that this isn't a conspiracy. Crypto services had to be verified by a key; the NSA's crypto services were classified, so they couldn't let Microsoft sign them; therefore, they needed their own key. The key is only used to authenticate crypto services, which I think Douglas Adams would describe as Mostly Harmless. I don't have the reverse engineering skills/IDA P…
1 - Privileged access to the dominant consumer operating system, also used by many corporations likely to be targeted.
2 - Minimal effort cost. Good will cost seems like something NSA ignores. Exposure to risk seems minimal given the existence of NDA contracts.
3 - I think anyone who isn't deluded and/or a member of the "nothing to hide; nothing to fear" camp already knows you can't trust Windows. The damage to the US economy seems minimal in light of the Snowden leaks that implicate nearly every US-based technology company, and Microsoft is investing heavily into things like X-box to diversify their revenue streams. I don't think there'd be any fallout worth mentioning, tbh.
When I put myself into the shoes of the DIRNSA and ask myself these questions, backdooring Windows seems like an obvious "Yes".
_NSAKEY may very well not be a backdoor, but I find the suggestion that Windows doesn't contain one to be laughably naive.
Earlier quoted context omitted.
A buddy who is an excellent reverse engineer assures me that this isn't a conspiracy. Crypto services had to be verified by a key; the NSA's crypto services were classified, so they couldn't let Microsoft sign them; therefore, they needed their own key. The key is only used to authenticate crypto services, which I think Douglas Adams would describe as Mostly Harmless. I don't have the reverse engineering skills/IDA P…
Answers from my POV: 1 - Privileged access to the dominant consumer operating system, also used by many corporations likely to be targeted. 2 - Minimal effort cost. Good will cost seems like something NSA ignores. Exposure to risk seems minimal given the existence of NDA contracts. 3 - I think anyone who isn't deluded and/or a member of the "nothing to hide; nothing to fear" camp already knows you can't trust Windows…
But NSAKEY isn't that.
Earlier quoted context omitted.
FPGA are very very inefficient at doing anything, they are very flexible and you can program them to perform specific operations very quickly relative to general purpose hardware however most of the silicon is dedicated to facilitate the programmability of the FPGA rather than the actual processing. If you only have access to commodity hardware than GPU's would probably be better. Xeon Phi is also insanely cheap righ…
Factoring RSA-2048 in 2020 sounds impossible. tptacek said it's extraordinarily unlikely NSA can scalably factor RSA-1024 today [1]. Look at how difficulty increases in the Yafu with GGNFS benchmark on wikipedia [2]. 1 - https://news.ycombinator.com/item?id=8844239 2 - https://en.wikipedia.org/wiki/RSA_%28cryptosystem%29#Integer...
NSA can virtually certainly target a specific, hardcoded 1024 bit key and break it. In fact, leaving out the cost and difficulty of recruiting the team to actually put the pieces together, the typical California venture capital firm has the resources to build a machine to do that today. Eran Tromer put the cost of such a machine in the single-digit millions, many years ago.
Apropos nothing: the gap between a 1024 bit key and a 2048 bit key is enormous. The thing that allows the NSA to meaningfully attack a 2048 bit key is likely to take RSA out altogether (and with it probably multiplicative finite field --- ie, "conventional" --- Diffie Hellman).