The data rate will be limited by the interface and the capabilities of the chip. The token can perform operations using stored private keys, and the private keys cannot leave the token at all. The other (better) way is to use the token's onboard hardware crypto. One is that a key file is stored on the token, and after authorization a program can request the file and then use it directly. A couple of modes of operation are typically possible depending on the hardware. The token itself is secured via a PIN, which must be entered by the user. What that kind of token does is offer secure hardware storage of various keys/certificates (or potentially other arbitrary data). I'll try to find some better resources as well (it's been a long time since I first started playing with this stuff), but you shouldn't have any trouble finding information via search engine. It's not very newbie friendly I'm afraid, but at least it has some terms that can get you started in searches. The OpenSC project is one of the major open source efforts, and can be integrated with OpenSSL and used by various applications, including Firefox. Some are very simple and meant for single user, some are intended for enterprise/government-class systems.

There are a lot of them, including both wholly proprietary systems and open ones. Click to expand.Go read about smart cards and USB tokens utilizing certificate/key structures.

Kdbx 4