No surprise, really. In fact, many companies have been using proprietary digital-signature technology for decades as part of electronic data interchanges. For now, your signature is likely to be a simple bit of encryption embedded in your PC that tells other computers that your request for a commercial transaction over the Internet is coming from your computer. In a couple of years, when technology improves, your signature could be an image of your retina, your fingerprint, or your face, scanned by a computer and matched with a bit of numeric code lodged on the servers of security companies that you've signed on with.
Nobody knows for sure yet.
But forget about writing your name in cyberspace. Computer-security companies design and incorporate these algorithms into software that customers can download from the Internet. But these keys are not interchangeable, like the key on your chain and the key under the rock by the porch, to unlock a house. With two keys at either end of the transaction, a consumer using a digital signature and a company providing a service over the Net could do business without divulging anything beyond that specific transaction. That will come when companies perfect techniques of facial recognition or fingerprint verification in conjunction with your encrypted signature key.