in internet there are many services that require a digital signature with a smart card.
I would like to know how it works... I can see that in eBay sell smart card with reader/writer for low money, but those companies that need Digital Signatures offer the same thing for much more money.
Is it the same stuff? If I buy one kit on eBay for about 20/30$, than I can pay taxes online and certify my Outlook emails?