I would say, there are known sub-exponential algorithms for factoring, while nothing better than (exponential) brute force is known for ECC. So, slightly better algorithms that erode RSA further are incremental improvements, while anything sub-exponential at all for ECC would be a breakthrough. Of course as someone once said, predictions are hard to make, especially about the future.
Just looking at the keys in authorized_keys, that short ECC key feels like any algorithmic breakthrough is going to turn it trivial… RSA already has those easier algorithms, but it also has the brute force bits to make the easier algorithms harder.
Most of us don’t have control over the public keys we use. We connect to a web site with a browser, and the server supplies the public key.
If you want public keys for your own purposes, I guess nothing stops you from generating 4096 bit (or whatever) ECC keys. Of course the arithmetic will be slow.
If you’re really paranoid about potential math advances affecting ECC and/or RSA, then you may be best off avoiding public key schemes altogether. Just use secret keys, and maybe Merkle tree signatures.
They can be less convenient, yes, but a situation where you need truly public keys is probably not that secure to begin with. If you’re just trying to talk to your friends from your tree house, symmetric encryption is completely practical, including using something like DUKPT for forward secrecy.
I would say, there are known sub-exponential algorithms for factoring, while nothing better than (exponential) brute force is known for ECC. So, slightly better algorithms that erode RSA further are incremental improvements, while anything sub-exponential at all for ECC would be a breakthrough. Of course as someone once said, predictions are hard to make, especially about the future.
Just looking at the keys in authorized_keys, that short ECC key feels like any algorithmic breakthrough is going to turn it trivial… RSA already has those easier algorithms, but it also has the brute force bits to make the easier algorithms harder.
Difficult to see, always moving the future is.
You could say the same things about AES keys being short.
And I do…
Academically, I trust the more modern algorithms with the shorter keys - not least because all the guidance says to trust them.
Viscerally, looking at the keys, the short ones just feel more vulnerable.
Most of us don’t have control over the public keys we use. We connect to a web site with a browser, and the server supplies the public key.
If you want public keys for your own purposes, I guess nothing stops you from generating 4096 bit (or whatever) ECC keys. Of course the arithmetic will be slow.
If you’re really paranoid about potential math advances affecting ECC and/or RSA, then you may be best off avoiding public key schemes altogether. Just use secret keys, and maybe Merkle tree signatures.
You mean symmetric keys? They’re great, but they aren’t terribly practical in MANY application scenarios.
They can be less convenient, yes, but a situation where you need truly public keys is probably not that secure to begin with. If you’re just trying to talk to your friends from your tree house, symmetric encryption is completely practical, including using something like DUKPT for forward secrecy.
A banking website?