GPG smartcards handling 4096-bit keys

Question

are there smartcards that handle 4096-bit keys supported both by GPG and Enigmail (PAM would be additional benefit)? Preferably on USB.

Answer 1

I'm quoting somebody else here:

Actually the OpenPGP Card / Crypto Stick can handle 4k keys as well but GnuPG is not able to handle 4k keys of smart cards. To use 4k keys either GnuPG needs to be patched

4096 support in smart cards is relatively rare, the common size is currently 2048 for RSA (cards do have EC support though). The CryptoStick claims to support 3k RSA keys but apparently only because that's the limit for GnuPG, the card should be able to do more.

Answer 2

Not sure if you can get cryptocards that support 4096-bit keys, but as long as they're a PKCS11 smartcard, you'll find they'll work with most things. I formatted an unused Aladdin eToken as a standard PKCS11 token, and had it working with OpenSSH and Firefox. Getting it working with GPG, Enigmail and PAM would be trivial, I suspect.

Have a look at some of the stuff that uses OpenSC - that tends to support many different kinds of tokens and cryptocards.