Hardware signatures

If you read Planet Debian as well as this blog, you probably have noticed the number of Debian developers that changed their keys recently, after the shadows cast over the SHA-1 hash algorithm. It is debatable on whether this is an issue now or not, but that’s not what I want to discuss.

There are quite a few reasons why Debian developers are more interested in this than Gentoo developers; while we also sign manifests, there are quite a few things that don’t work that well in our security infrastructure, which we should probably pay more attention to (but I don’t want to digress now), so I don’t blame their consideration of tighter security.

I’m also considering the switch; while I have my key for quite a while, there are a few issues with it: it’s not signed by any Gentoo developer (I actually don’t think I have met anybody in person to be able to exchange documents and stuff), the Manifest signing key is not a subkey of my actual primary key (which by the way contains lots of data of my previous “personas” that don’t matter any longer), and so on so forth. Revoking this all and starting anew might be a good solution.

But, before proceeding, I want finally go get over with the thing and move to hardware cryptography if possible; I already expressed the interest before, but I never dug enough to find the important information, now I’m looking for that kind of information. And I want a solution that works in the broadest extension of cases:

  • I want it to work without SHA-1; I guess this starts already to be difficult; while it’s not clear whether SHA-1 is weak enough to be a vulnerability or not, being able to ignore the issue by using a different algorithm is certainly a desirable feature;
  • I want it to work with GnuPG and OpenSSH at least; if there is a way to get it to work with S/MIME it might also be a good idea;
  • I want it to work on both Linux and Mac OS X: I have two computers in my office: Yamato running Gentoo and Merrimac running OSX; I have to use both, and can’t do without either; I don’t care if I don’t have GnuPG working on OSX, I still need it to work with OpenSSH, since I would like to use it for remote access to my boxes;
  • as an extension to the previous point, I guess it has to be USB; not only I can switch it between the two systems (hopefully!), I’m also going to get a USB switch to use a single console between the two;

I guess the obvious solution would be a tabletop smartcard reader with one or more cards (and I could get my ID card to be a smartcard), but there is one extra point: one day I’m going to have a laptop again, what then? I was thinking about all-in-one tokens, but I have even less knowledge about those than I have about smartcards.

Can anybody suggest me a solution? I understand that the FSFE card only supports 1024 bit for the keys, which seems to be tied to weakness lately, no idea how much of that is true though, to be honest.

So, suggestions, very welcome!

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