RSA-1024 is approx 6 bits more security than the RSA-260 challenge, so ~64x more work to factor. That is negligible by cryptographic standards.
We don't know yet how much work OP put into factoring the RSA-260 challenge. No doubt it was a lot, but probably done with general purpose GPU hardware. That will continue to get cheaper to mount in the near future, and we ought to assume that nation states have access to RSA factoring hardware that would be multiple orders of magnitude more efficient.
It is quite likely that there are at least two actors (US and China) that can break RSA-1024, and they are no doubt working through a priority list of all accessible servers with such weak keys. If your firewall is not broken & now back-doored, it is only because you're not important enough to have gotten to yet.
RSA-2048 (or better, RSA-3072) is usually a drop-in replacement. ECC would be even better. There is no reason not to.
You are right that there are better options and there is no excuse not to choose something better today. But that’s not what GP is arguing! It’s just that: For any given interest level there is no way that expending the resources to attack the RSA key is valuable! You are either willing to expend resources then attacking the owner is far cheaper or not then you are also not investing weeks-to-month of cluster time.
And from that perspective RSA-1024 is still perfectly adequate
You don't know that. We're at the point where the NSA can assuredly break RSA-1024. We know they have sufficient processing power, and it would be silly of them not to have developed that capability.
"But they're not going to spend resources breaking my router!" No, not your router specifically. But batch GCD gives sqrt speedup over multiple keys, potentially 10's to 100's of millions of keys at once with off-the-shelf GPU clusters at NSA scale. Looking at that many keys at once tends to discover low-entropy biases common in consumer router hardware, which makes brute-forcing new keys from those devices trivial to do.
If you are actually operating a service relying on RSA-1024 security, it is almost certainly pwoned.
If you are actually operating a service relying on RSA-1024 security, it is almost certainly pwoned.
If you're running something with code from a large US corporation, or outsourced to contractors, or made in China, or with a web interface, or [3 more pages of stuff] and your main worry is the size of your RSA keys, then I've got a Fortigate security appliance to sell you.
I would have formulated it less dismissively than my sibling but yes. There are ~no scenarios, where the Cloud act is not the more straightforward solution. Even factoring RSA-1024 will take non-zero compute time. And that can be spend more productively
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ECC does have the benefit of smaller keys, but yes, RSA seems fine security-wise for the foreseeable future.
RSA-1024 absolutely is not.
Why not? What's the actual threat? Let's say I'm using RSA-1024 on my firewall today. What happens next?
RSA-1024 is approx 6 bits more security than the RSA-260 challenge, so ~64x more work to factor. That is negligible by cryptographic standards.
We don't know yet how much work OP put into factoring the RSA-260 challenge. No doubt it was a lot, but probably done with general purpose GPU hardware. That will continue to get cheaper to mount in the near future, and we ought to assume that nation states have access to RSA factoring hardware that would be multiple orders of magnitude more efficient.
It is quite likely that there are at least two actors (US and China) that can break RSA-1024, and they are no doubt working through a priority list of all accessible servers with such weak keys. If your firewall is not broken & now back-doored, it is only because you're not important enough to have gotten to yet.
RSA-2048 (or better, RSA-3072) is usually a drop-in replacement. ECC would be even better. There is no reason not to.
You are right that there are better options and there is no excuse not to choose something better today. But that’s not what GP is arguing! It’s just that: For any given interest level there is no way that expending the resources to attack the RSA key is valuable! You are either willing to expend resources then attacking the owner is far cheaper or not then you are also not investing weeks-to-month of cluster time.
And from that perspective RSA-1024 is still perfectly adequate
You don't know that. We're at the point where the NSA can assuredly break RSA-1024. We know they have sufficient processing power, and it would be silly of them not to have developed that capability.
"But they're not going to spend resources breaking my router!" No, not your router specifically. But batch GCD gives sqrt speedup over multiple keys, potentially 10's to 100's of millions of keys at once with off-the-shelf GPU clusters at NSA scale. Looking at that many keys at once tends to discover low-entropy biases common in consumer router hardware, which makes brute-forcing new keys from those devices trivial to do.
If you are actually operating a service relying on RSA-1024 security, it is almost certainly pwoned.
If you're running something with code from a large US corporation, or outsourced to contractors, or made in China, or with a web interface, or [3 more pages of stuff] and your main worry is the size of your RSA keys, then I've got a Fortigate security appliance to sell you.
I would have formulated it less dismissively than my sibling but yes. There are ~no scenarios, where the Cloud act is not the more straightforward solution. Even factoring RSA-1024 will take non-zero compute time. And that can be spend more productively
Not all attackers pay for compute. With enough stolen compute, breaking RSA-1024 is free and not that slow...